Contents
2006
Volume: 26 Issue 2
31 Article(s)
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Fiber Optics and Optical Communications
Study of Soliton Pulse with Small Pedestal Based on Adiabatic Soliton Compression Effects
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The generation of ultra-short optical pulses with high repetition rate is one of the key technologies for high-speed optical time division multiplexing systems. However, the pulses directly generated by ordinal ultra-short pulse sources are usually not narrow enough. To meet the demand of high-speed optical communicatiThe generation of ultra-short optical pulses with high repetition rate is one of the key technologies for high-speed optical time division multiplexing systems. However, the pulses directly generated by ordinal ultra-short pulse sources are usually not narrow enough. To meet the demand of high-speed optical communication systems, the pulses should be compressed. Using a 360 m dispersion decreasing fiber, 5.40 ps and 4.60 ps pulses with the repetition rate of 10 GHz and central wavelength of 1546 nm generated from a regeneratively mode-locked fiber laser (RMLFL) are adiabatically compressed into soliton pulses with pulse-width of 1.93 ps and 1.71 ps, respectively. The compression factors are 2.80 and 2.69, respectively. With a high quality and a small pedestal, the compressed solition pulse can be applied to 160 Gb/s optical time division multiplexing system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 166 (2006)
Influence of Lateral Pressure on Phase and Group Modal Birefringence in Microstructure Fiber
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The influence of lateral pressure on the birefringent characteristics of high-birefringent microstructure fiber is theoretically investigated using a full-vector finite element method, which is different from other reports applying hydrostatic pressure. In the wavelength range 600～1700 nm, the results indicate that theThe influence of lateral pressure on the birefringent characteristics of high-birefringent microstructure fiber is theoretically investigated using a full-vector finite element method, which is different from other reports applying hydrostatic pressure. In the wavelength range 600～1700 nm, the results indicate that the variation of the phase and group modal birefringence is different, when the lateral pressure is applied along the slow axis and fast axis of the microstructure fiber, respectively. Furthermore, when the lateral pressure is applied along the slow axis and fast axis, respectively, the effect of lateral pressure on the sensitivity of phase and group modal birefringence of microstructure fiber is also different. The research has great signification in microstructure fiber designing, microstructure fiber sensors especially multidimensional optical fiber sensors..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 171 (2006)
Acquisition and Tracking of Image Beacon for Deep Space Optical Communication
[in Chinese], [in Chinese], and [in Chinese]
With laser to return the scientific data of deep space exploration to earth, the up beacon cannot provide enough tracking rate for its serious optical attenuation, so the image of a natural object is usually used as the beacon. Successful acquisition and beacon tracking is the key of setting and keeping the deep space With laser to return the scientific data of deep space exploration to earth, the up beacon cannot provide enough tracking rate for its serious optical attenuation, so the image of a natural object is usually used as the beacon. Successful acquisition and beacon tracking is the key of setting and keeping the deep space optical communication link. Storing an image in the aircraft as the reference, using the correlation of the reference image and the detected image to acquire the beacon, the theoretical analysis and computer simulation show that it can accurately confirm the initialized pointing direction of the optical antenna and make PAT subsystem enter the tracking model. Calculating the translation of beacon based on discrete Fourier transform (DFT) and maximum likelihood criterion, need solve two nonlinear equations, and the linearly approximated result shows that the total translation error is below 0.5 pixel, the translation error in X direction is 3.3%, and the translation error in Y the direction is 2.7%, can meet the need of deep space optical communication, so it is a feasible scheme..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 176 (2006)
Hybrid OCDMA Coding Scheme of Time-Spatial Frequency Spreading Spectrum Based On Optical Imaging Transmission
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
For using the time and space frequency resources in imaging transmission fully, a new hybrid optical code division multiaddress (CDMA) coding scheme is proposed, which is based on imaging transmission with two-dimensional optical orthogonal pattern code and time frequency spread spectrum. Then the authors analyze the mFor using the time and space frequency resources in imaging transmission fully, a new hybrid optical code division multiaddress (CDMA) coding scheme is proposed, which is based on imaging transmission with two-dimensional optical orthogonal pattern code and time frequency spread spectrum. Then the authors analyze the multiplex access interference noise and calculate the probability density function of interference noise in interfering optical orthogonal signature codes. The bit-error rate caused by the multiplex access interference noise is derived and plotted as a function of receiver threshold, number of users, code length and code weight product. Compared respectively with time spreading code and spatial spreading code optical CDMA, the authors' scheme has a lower bit-error rate and releases the requisition of relative devices such as the number of code chips in time domain and the pixels in space domain. Finally a design scheme of encoder-decoder is presented..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 181 (2006)
Research on Pupil Configuration of Dual Three Sub-Apertures Sparse-Aperture System
[in Chinese], [in Chinese], and [in Chinese]
The modulation transfer function (MTF) of a sparse-aperture system is lower than that of a filled-aperture system within the cut-off frequency. The zero values of MTFs may be produced at some mid-spatial frequencies, which affects the image quality. Configuration optimization of sparse-aperture systems can achieve a spThe modulation transfer function (MTF) of a sparse-aperture system is lower than that of a filled-aperture system within the cut-off frequency. The zero values of MTFs may be produced at some mid-spatial frequencies, which affects the image quality. Configuration optimization of sparse-aperture systems can achieve a sparse-aperture configuration with more uniform MTF. A criterion is given to optimize the sparse-aperture system, which is directly linked with the maximum spatial frequency ρR (or practical resolution) and the diameters of the sub-apertures. Optimal configuration of dual three sub-apertures and the image simulations are obtained. Wiener filter technique is applied. The image simulations and the MTFs comparison of optimized configuration and un-optimized configuration of dual three sub-apertures show that configuration optimization is a key aspect of the design for sparse-aperture systems. The optimization criterion of sparse-aperture systems is reasonable and the image quality can be improved by optimizing configuration..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 187 (2006)
Instrumentation, Measurement and Metrology
Three-Dimensional Displacement Measurement in Electronic Speckle Pattern Interferometry by Using Reversed Phase Calculation
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A method for three-dimensional displacement measurement by separating out-of-plane displacement from in-plane displacement is presented. A reference laser beam is added to dual beam symmetric illumination electronic speckle pattern interferometric (ESPI) system and is shared by the two illumination beams. The two illumA method for three-dimensional displacement measurement by separating out-of-plane displacement from in-plane displacement is presented. A reference laser beam is added to dual beam symmetric illumination electronic speckle pattern interferometric (ESPI) system and is shared by the two illumination beams. The two illumination beams are used separately in experiment for the displacement measurement. Then two phase maps, including out-of-plane and in-plane displacement, are obtained with phase shifting technique, then one of which is calculated by reversed phase calculation method. Theoretical analysis shows that subtraction of the phase maps can greatly decrease electronic noises, separate out-of-plane displacement easily from in-plane displacement and complete three-dimensiomal displacement measurement. The principle of the method is presented and proved by a typical three-point-bending experiment..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 193 (2006)
Research of High-Accuracy Digital Image Correlation Measurement System
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new high-accuracy digital image correlation measurement system based on double long-focus CCD microscope is presented. Combining photoelectric, digital image correlation and speckle technology, it has advantages of non-contact measurement, high accuracy, wide range, quasi real time, convenient operation, and can be uA new high-accuracy digital image correlation measurement system based on double long-focus CCD microscope is presented. Combining photoelectric, digital image correlation and speckle technology, it has advantages of non-contact measurement, high accuracy, wide range, quasi real time, convenient operation, and can be used to measure mechanical property of materials (especially flexible high molecular synthetic materials) and linear expansibility of novel low expansibility material. Sensitivity is less than 1 με when the system is used in strain measurement, while the theoretical sensitivity of conventional digital image correlation technology is 20 με. Array optical element is used to set the micro high contrast mark of 0.05 mm. Time-average method is used to eliminate the gray noise of digital image and makes the correlation measurement accuracy achieve 0.01 pixel stably. Experimental result of the tension stress measurement for metal material is listed, and the result shows the accordance with the theoretical value. Moreover, digital image correlation measurement method is described as a measurement technique which has better resolution than Rayleigh criterion..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 197 (2006)
Optical Testing of Dynamic Characteristics of a Micro-Machined Vibratory Gyroscope
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
To evaluate precisely the dynamic characteristics of the resonator of a micro-machined vibratory gyroscope during its design process, an optical method for measuring the dynamic characteristics of a micro-resonator is proposed. In the proposed method, a digital image correlation technique is used to calculate the correTo evaluate precisely the dynamic characteristics of the resonator of a micro-machined vibratory gyroscope during its design process, an optical method for measuring the dynamic characteristics of a micro-resonator is proposed. In the proposed method, a digital image correlation technique is used to calculate the correlation coefficients among the temporal series images of the micro-resonator captured using a high\|speed video camera in order to acquire the displacement, velocity and accelerator curves of the micro-resonator in the atmosphere, and then the natural frequency and the quality factor of the micro-resonator is obtained accordingly. The proposed approach has a high precision since the vibrating displacement is measured at submicrometer resolution. The natural frequency and the quality factor in atmosphere for the driving mode of the tested gyroscope are measured as 2061.67 Hz and 66.67 respectively. The present method may provide an accurate and effective measurement tool for the evaluation of the dynamic characteristics of a micro-machined vibratory gyroscope..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 202 (2006)
Integrated Optics
Characteristic Analyses of Series-Coupled Multiple-Ring Resonator Filter
[in Chinese], [in Chinese], and [in Chinese]
By introducing the equivalent four-port network, the general formulas for the series-coupled multiple-ring resonator were derived with the transfer matrix method. The characteristic parameters of series-coupled double-rings resonator such as, amplitude flatness, bandwidth and phase group delay, were analyzed and optimiBy introducing the equivalent four-port network, the general formulas for the series-coupled multiple-ring resonator were derived with the transfer matrix method. The characteristic parameters of series-coupled double-rings resonator such as, amplitude flatness, bandwidth and phase group delay, were analyzed and optimized. Numerical results demonstrated that the propagation loss on the device was negligible with improved fabrication techniques. Since filter performances were determined by the coupling coefficients, the maximal flat response with sharper rolloff could be achieved by setting coupling coefficients symmetric and smaller in the middle. Compared with single-ring resonator, the series-coupled multiple-rings structure obviously improved the amplitude response and eliminated the second-order group delay dispersion..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 207 (2006)
Lasers and Laser Optics
M2-Factor of Partially Coherent Gaussian Schell-Model Beams Propagating in Media
[in Chinese], and [in Chinese]
Considering of the complex wave number, the second-order intensity moments and the M2-factor of partially coherent beams have been modified. A partially coherent Gaussian Schell-model beam progating in media is taken as typical example to study the change of M2-factor. It can be shown that unlike in free-space, the M2-Considering of the complex wave number, the second-order intensity moments and the M2-factor of partially coherent beams have been modified. A partially coherent Gaussian Schell-model beam progating in media is taken as typical example to study the change of M2-factor. It can be shown that unlike in free-space, the M2-factor of partially coherent beams in the gain or absorbing media does not only depend on the coherent parameter β. In gain media, the M2-factor increases with the increase of the propagation distance B and the parameter characterizing the media Ki, and with the decrease of the coherent length σ0 and the wave number Kr, whereas in absorbing media, the M2-factor decreases with the increase of the propagation distance B and the parameter characterizing the media Ki, and with the decrease of the coherent length σ0 and the wave number Kr. The result can offer some effective methods of beam quality control..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 212 (2006)
Experimental Study on Low-Noise Fiber Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
With the rapid progress of optical sensors and optical communications, the laser source with low phase noise and intensity noise is in urgent demand. To meet the needs, a novel low-noise fiber laser with compound cavity structure is designed. The stable single-mode operation is realized by using a transient self-writteWith the rapid progress of optical sensors and optical communications, the laser source with low phase noise and intensity noise is in urgent demand. To meet the needs, a novel low-noise fiber laser with compound cavity structure is designed. The stable single-mode operation is realized by using a transient self-written fiber grating, produced by the effect of saturable absorption within a section of unpumped erbium-doped fiber, as narrow band filter for mode selecting and linewidth squeezing. Through optical path modification, the spectral signal-to-noise ratio is better than 62 dB. With opto-electronic negative feedback, the intensity noise of the source is well suppressed, the intensity noise in the low frequency band is greatly improved and the relaxation oscillation peak is reduced with about 25 dB. The laser has an output power more than 1 dBm, linewidth less than 1 kHz, and side-mode-suppression ratio larger than 50 dB. The excellent noise property indicates that the source has important applications in optical sensors and optical communications..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 217 (2006)
Materials
Optical Properties of p-Type GaAs in Far-Infrared Region
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
GaAs is an important material for the fabrication of semiconductor heterostructure lasers working at terahertz frequencies. To study the optical properties of p-type GaAs in far-infrared region, p-type (Be-doped) GaAs with carrier concentrations varied from 1.54×1015～ 1.85×1019 cm-3 has been epitaxially grownGaAs is an important material for the fabrication of semiconductor heterostructure lasers working at terahertz frequencies. To study the optical properties of p-type GaAs in far-infrared region, p-type (Be-doped) GaAs with carrier concentrations varied from 1.54×1015～ 1.85×1019 cm-3 has been epitaxially grown by gas source molecular beam epitaxy (GSMBE) on semi-insulating GaAs(100) substrates. Fourier transform infrared (FTIR) spectrometer is employed to characterize far-infrared reflectance spectra of the p-type GaAs. Simulation of the measured far-infrared reflectance spectra has been performed. And refractive indices, extinction coefficients and absorption coefficients for different carrier concentrations have been determined. It is found that extinction coefficients and absorption coefficients increase with the carrier concentration in far-infrared region, and the maximum of absorption coefficients can reach 4.0×104 cm-1..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 221 (2006)
Invesitigation on Upconversion Luminescence of Yb3+-Sensitized Tm3+-Doped Oxyhalide Tellurite Glasses
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The effects of Yb2O3 concentration on upconversion luminescence spectra of Tm3+/Yb3+-codoped oxyhalide tellurite glasses were studied, and upconversion luminescence mechanism of Yb3+ sensitize Tm3+ in oxyhalide tellurite glasses was analyzed. The results showed that intense blue (475 nm) and weak red (649 nm) emission The effects of Yb2O3 concentration on upconversion luminescence spectra of Tm3+/Yb3+-codoped oxyhalide tellurite glasses were studied, and upconversion luminescence mechanism of Yb3+ sensitize Tm3+ in oxyhalide tellurite glasses was analyzed. The results showed that intense blue (475 nm) and weak red (649 nm) emission corresponding to the 1G4→3H6 and 1G4→3F4 transitions of Tm3+, respectively, were simultaneously observed at room temperature under 980 nm laser diode (LD) excitation. Upconversion mechanism analysis showed that a two-photon upconversion process is assigned to the blue and red emission; with increasing Yb2O3 concentration, the lifetime of Yb3+ decreases, the energy transfer efficiency of Yb3+ to Tm3+ increases, upconversion blue and red emission intensities first increase, reach its maximum at molar ratio 3 of Yb2O3 concentration, and then decrease. It is considered that the concentration quenching of Yb3+ is due to energy back-transfer of 3H4 (Tm3+)→2F5/2(Yb3+). The results showed that Yb3+-sensitized Tm3+-doped oxyhalide tellurite glasses can be used as a kind of potential host materials for upconversion blue lasers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 225 (2006)
Medical Optics and Biotechnology
Optical System of Potential Vision Meter
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An instrument to measure the retinal potential visual acuity (PVA) of the patients, suffering from cataract, is studied. This instrument uses a transparent eye chart. With special optical system, the beam from the exit pupil of the instrument is thin enough to pass through the aperture of the opacity lens of eyes with An instrument to measure the retinal potential visual acuity (PVA) of the patients, suffering from cataract, is studied. This instrument uses a transparent eye chart. With special optical system, the beam from the exit pupil of the instrument is thin enough to pass through the aperture of the opacity lens of eyes with cataract and forms image on the retina. The move of the eye chart makes it possible to measure the PVA of the patients with diopter -7～+12 m-1. The design of the configuration of the instrument and some theoretical calculation are finished, along with experiments and tests. The experiment shows that the diameter of the spot at the exit pupil is 0.094 mm, and the vision measured with potential vision meter (PVM) accords with that measured with traditional method. The PVA of the patients can be accurately measured with the instrument before the operation, which is important to both the doctors and the patients..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 230 (2006)
Development of Fiber-Based Optical Coherence Tomographic Imaging System
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Optical coherence tomography (OCT) is a recently developed high resolution biomedical imaging method, allowing for noninvasive visualizing of internal tissue structure and physiology. It is built that a newly developed single-mode fiber-designed OCT system based on Michelson interferometer and optical heterodyne detectOptical coherence tomography (OCT) is a recently developed high resolution biomedical imaging method, allowing for noninvasive visualizing of internal tissue structure and physiology. It is built that a newly developed single-mode fiber-designed OCT system based on Michelson interferometer and optical heterodyne detection using a broadband near-infrared light source. With this developed system elastic light backscattered from the tissue is picked up, and two-dimensional (2-D) and three-dimensional (3-D) OCT images are reconstructed. Fiber-based OCT system is compact, flexible, and convenient to be combined with fiber catheter, endoscope and other imaging equipments to expand its observing scope and application fields..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 235 (2006)
Microscopy
Influence of Depth of Field on Resolution of a Microscope Polarization Interference Imaging Spectrometer
[in Chinese], and [in Chinese]
A scheme of microscope polarization interference imaging spectrometer (MPIIS) based on a Savart polariscope and its basic principles are introduced, and the relative expression of depth of field of MPIIS is derived with the geometrical-optics method. The relationship between the depth of field and the spectral resolutiA scheme of microscope polarization interference imaging spectrometer (MPIIS) based on a Savart polariscope and its basic principles are introduced, and the relative expression of depth of field of MPIIS is derived with the geometrical-optics method. The relationship between the depth of field and the spectral resolution is given. It proves that the existence of the depth of field renders the spectral resolution value unfixed, but changing continuously within a certain range. The influence of depth of field on resolution value of a MPIIS is analyzed through computer simulation. All of this provide important theoretical bases and practical guidances for realizing real-time measurement, decreasing influence of depth of field on spectral resolution, and the study, design and engineering of novel polarization interference imaging spectrometers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 239 (2006)
Optical Design and Fabrication
Design of Volume Holographic Storage Optical System with Common Optical Axis for Signal Beam and Reference Beam
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The volume holographic storage optical system can be simplified, using the common optical axis for signal beam and reference beam by locating two diffusers on both sides of the incident plane. However, in this kind of holographic storage optical system, the total numerical aperture for signal beam and reference beam isThe volume holographic storage optical system can be simplified, using the common optical axis for signal beam and reference beam by locating two diffusers on both sides of the incident plane. However, in this kind of holographic storage optical system, the total numerical aperture for signal beam and reference beam is much larger than the numerical aperture for signal beam. The design requirement and optical parameter determination about signal optical path and reference optical path in this volume holographic storage optical system have be analyzed. In order to correct aberration in positive optical path and reverse optical path for the object beam, and meet the demand of reference beam at the same time, the multi-configuration method has been adopted to optimize the positine and reverse optical path of the object beam and the optical path of the reference beam. A holographic storage optical system with common optical axis for signal beam and reference beam achieving diffractive-limit has been designed. The focal lengths of the front and rear group lens are 33 mm and 30 mm, respectively, its front work distance is 30 mm, its back group lens has 30 mm focal length, its total numerical aperture for signal beam and reference beam is 0.53, and the wave aberration of the system is less than 0.071λ..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 244 (2006)
Design of an Ultralight and Compact Hybrid Refractive-Diffractive Projection Lens of Head-Mounted Projective Displays
[in Chinese], and [in Chinese]
Based on a 7-element lens, a refractive lens system and a 5-element hybrid refractive-diffractive lens system are designed. The optimization procedure and the performance of the systems are presented in detail. The systems are desigzned for a 1.3 inch (～3.3 cm) liquid crystal display (LCD) with 56° field of view, Based on a 7-element lens, a refractive lens system and a 5-element hybrid refractive-diffractive lens system are designed. The optimization procedure and the performance of the systems are presented in detail. The systems are desigzned for a 1.3 inch (～3.3 cm) liquid crystal display (LCD) with 56° field of view, 10 mm exit pupil diameter and 25 mm eye relief. The refractive projection system has a 28 mm diameter and 33 g weight. And the hybrid refractive-diffractive system has a 22.4 mm diameter and 11.9 g weight only. The maximum distortions of the two systems are less than 3.2% and 0.17%, respectively. Both the refractive and the hybrid refractive-diffractive system can display SXGA mode images, act as projection system of head-mounted projective displays (HMPDs) in the fields of medical collaborative environments, medical visualization for training, soldier equipped with digital system, and so on..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 249 (2006)
Optical Devices
Electro-Optical Switch with 280 mm×280 mm Aperture Drived by One-Pulse Process
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The large aperture optical switch used in the high-power laser driver for inertial confinement fusion adopts the plasma electrode Pockel cell. Being different with the regular plasma electrode electrooptical switch, the one-pulse-process (OPP) driving electrooptical switch is driven only through the positive and negatiThe large aperture optical switch used in the high-power laser driver for inertial confinement fusion adopts the plasma electrode Pockel cell. Being different with the regular plasma electrode electrooptical switch, the one-pulse-process (OPP) driving electrooptical switch is driven only through the positive and negative switching pulses with relatively high voltage, without isolated large current plasma generator. The design of the OPP electrooptical switch is described, and the experimental setup of the electrooptical switch with 280 mm×280 mm aperture is established. The testing results of the electrooptical switch with CW laser show the switch efficiency of this electrooptical switch is 99.3%, and the switch rising time is 90 ns..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 254 (2006)
A New Grooved Mirror of the Ring Laser Gyro
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Analyzed the shortcoming of traditional grooved mirror used on the ring laser gyro (RLG) about its masterial and structure, a new structure of grooved mirror was designed, which syncretized the advantanges of both of glass-ceramic (zerodur) and fused quartz. The body of the mirror is made of glass-ceramic, the same matAnalyzed the shortcoming of traditional grooved mirror used on the ring laser gyro (RLG) about its masterial and structure, a new structure of grooved mirror was designed, which syncretized the advantanges of both of glass-ceramic (zerodur) and fused quartz. The body of the mirror is made of glass-ceramic, the same material of the gyro block. The reflective stice is made of fused quartz, whose surface can be polished to higher quality. These two components are combined to become the new mirror. Accordingly a new method was put forward to machine the gyro block surface on which the grooved mirror fixed. It can make the block to suit to the new mirror without more difficulties. A new method was also put forward to polish the substrate and the spherical surface of the mirror separately. Not only has it resolved the problem that the helium leaks through the fused silica material, but also reduced the difficulties is superpolishing the surface of the mirror's substrate..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 259 (2006)
A Novel-High Sensitivity Refractive Index Sensor with Temperature Self-Compensating
[in Chinese], [in Chinese], and [in Chinese]
Based on the novel ultra-long-period fiber grating (ULPFG) written by the high-frequency CO2 laser pulses, a new high-sensitivity refractive index sensor with temperature self-compensating is proposed. The theoretical and experimental results show that different shining order resonant peaks of the ULPFG have different Based on the novel ultra-long-period fiber grating (ULPFG) written by the high-frequency CO2 laser pulses, a new high-sensitivity refractive index sensor with temperature self-compensating is proposed. The theoretical and experimental results show that different shining order resonant peaks of the ULPFG have different temperature and refractive index sensitivities. Especially, it is found that there appears one resonant peak of ULPFG insensitive to the refractive index, which offers the potential application for simultaneous temperature measurement and can compensate the measurement errors induced by temperature change when other resonant peaks are measured. This refractive index sensor is simple, with a low cost, good strength and high sensitivity, when the surrounding refractive index varies in the range of 1.43～1.45, the refractive index measurement has a sensitivity of 240 nm/per unit refractive index, which has great potentials in industry applications..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 264 (2006)
Phase-Shifting Vectorial-Shearing Interferometer with Mach-Zehnder Configuration
[in Chinese], [in Chinese], and [in Chinese]
A novel phase-shifting vectorial-shearing interferometer with a wedge plate phase-shifter is presented to measure the laser wavefront, which is common-path and based on Mach-Zehnder configuration. Vectorial shear (shearing in x and y directions simultaneously) in arbitrary direction is introduced by inserting two wedgeA novel phase-shifting vectorial-shearing interferometer with a wedge plate phase-shifter is presented to measure the laser wavefront, which is common-path and based on Mach-Zehnder configuration. Vectorial shear (shearing in x and y directions simultaneously) in arbitrary direction is introduced by inserting two wedge plates orthogonally in two arms, respectively. One of wedge plates is split into two parts (parallel part and wedge part), and the phase shift is produced by moving the wedge part in contact along the parallel part, which results in the variation of the optical path difference. The moving distance for 2π phase shift is about several millimeters in a specific condition. Wedge plate phase-shifter increases the moving distance of PSI and makes the control of phase shift relatively easy. The lateral shear errors and phase shift errors induced by wedge plates are also discussed, and the experimental results of phase-shifting vectorial-shearing interference fringes are given..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 269 (2006)
OPTOELECTRONICS
Novel Blue Organic Light Emitting Diode with Highly Saturated Color and Weak Current-Induced Quenching
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Four blue organic light emitting diodes (OLED) based on anthracene derivatives( ADN) doped with different dopants have been prepared. The device structure is CuPc(12 nm)/NPB(40 nm)/ADN∶Dopant(50 nm)/Alq(12 nm)/LiF(4 nm)/Al. The four dopants are amino-substituted distyrylarylene derivatives(BCzVB), tetra-butylperylene (Four blue organic light emitting diodes (OLED) based on anthracene derivatives( ADN) doped with different dopants have been prepared. The device structure is CuPc(12 nm)/NPB(40 nm)/ADN∶Dopant(50 nm)/Alq(12 nm)/LiF(4 nm)/Al. The four dopants are amino-substituted distyrylarylene derivatives(BCzVB), tetra-butylperylene (TBPe), BCzVBi and DSA-ph. The optium concentration of dopants, the luminescence, current density, efficiency and color coordinates of these devices are explored. The device based on ADN doped with BCzVB shows high color purity and a weak current-induced fluorescence quenching. With CIE coordinates x=0.146,y=0.162, maximum luminance 11600 cd/m2 (15 V), current efficiency 2.8 cd/A, and luminous efficiency 1.79 lm/W. For comparison, the blue OLEDs based on ADN doped with TBPe BCzVBi and DSA-ph are also made. The first exhibits CIE coordinates x=0.162, y=0.222 (greenish blue) and a steep decline of efficiency with the increase of the current. The second gives a better purity (x=0.164,y=0.146) but lower current steeply declining with increase of current efficiency 2.03 cd/A. The last has high efficiency 8 cd/A and a weak current-induced fluorescence quenching, but poor CIE coordinates x=0.153，y=0.306, and it is suitable for white OLED..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 275 (2006)
Photonic Band Gap of the Distorted Face-Center-Cubic Structure Photonic Crystal Fabricated by Holographic Lithography
[in Chinese], [in Chinese], and [in Chinese]
The face-center-cubic structure obtained by four incident laser beams directly from air to photoresist of planar construction, is actually a kind of distorted face-center-cubic structure. Both of its lattices and its latticesites are lengthened along [111] direction. In the study on the lattice shape and band structureThe face-center-cubic structure obtained by four incident laser beams directly from air to photoresist of planar construction, is actually a kind of distorted face-center-cubic structure. Both of its lattices and its latticesites are lengthened along [111] direction. In the study on the lattice shape and band structure of this distorted face-center-cubic structure, using MIT's Photonic-Bands program, after calculating the relations between the energy band structure and all kinds of parameters of opal and inverse opal, a complete photonic band-gap in its opal structure is obtained. The largest photonic band-gap is obtained as the lengthening ratio is 2.1 and the filling ratio of silica is 13.7%. For fabrication of this structure with largest photonic band-gap by holographic lithography method, which needs two steps (fabrication of opal and fabrication of inverse opal by filling), the three outer beams are placed symmetrically around the central beam, the three outer beams are 54.0° apart, and the angles between the central beam and outer beams are 31.6°..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 279 (2006)
Synthesizer of Electro-Optical Birefringent System in Time Domain
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A synthesizer for waveform generation utilizing electro-optical birefringent networks is described, which consists of two polarizers, electro-optical elements and phase compensators. When a cosine function voltage is applied on the electro-optical crystals, this system acts as a multiple electro-optical birefringent neA synthesizer for waveform generation utilizing electro-optical birefringent networks is described, which consists of two polarizers, electro-optical elements and phase compensators. When a cosine function voltage is applied on the electro-optical crystals, this system acts as a multiple electro-optical birefringent network for synthesis of time domain waveform. Analysis in time domain based on Jones matrix theory is given for the synthesizer. The algorithm comparing of Fourier series coefficients in positive-direction is used to design the synthesizer producing other types of periodical waveforms in time domain. A kind of three-stage synthesizer is elaborated as an example and multiple structural parameters have been obtained for rectangular and triangular waveforms. The factors influencing the waveform, including the input signal error and the azimuth angle are also discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 283 (2006)
Physical Optics
Study on Encoding Using LiNbO3 Crystal in Laser Polarization Encoding Guidance
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In order to solve the theoretical limitation of laser beam energy modulating commonly applied in existing laser beam-rider guidance system, the principle of realization of space polarization encoding and decoding using lithium niobate (LiNbO3) crystal for its electrooptic effect is studied. The electrooptic effect of LIn order to solve the theoretical limitation of laser beam energy modulating commonly applied in existing laser beam-rider guidance system, the principle of realization of space polarization encoding and decoding using lithium niobate (LiNbO3) crystal for its electrooptic effect is studied. The electrooptic effect of LiNbO3 crystal is analyzed, based on which a modulator used in space polarization encoding system is designed. And applying the electric field in X direction is found to be the best means to make linear polarization have an expected polarization gradient distribution after passing encoder. Discussion of received data processing way proves that the difference over sum method is independent of rotation. Near field experiments using visible light in laboratory have got polarization states varying through approximately right-handed circular polarization on the top of the beam to the linear polarization at the center of the beam and then to left-handed circular polarization at the bottom of the beam. The curves of experiments show that experimental results accord with theoretical calculation basically..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 290 (2006)
Characteristics of Aperture-Array Diffraction and Its Application
[in Chinese], [in Chinese], and [in Chinese]
Based on the diffraction theory of monochromatic scalar wave，the characteristics of plane wave with uniform intensity diffracted by aperture-array from different angles were investigated. Considering the effect of the near apertures, the theoretical model and intensity distribution numerical integral expression were esBased on the diffraction theory of monochromatic scalar wave，the characteristics of plane wave with uniform intensity diffracted by aperture-array from different angles were investigated. Considering the effect of the near apertures, the theoretical model and intensity distribution numerical integral expression were established on the base of aperture diffraction theory, where the apertures are hard-edged. The intensity distribution patterns of diffraction when plane light with 500 nm wavelength went through the aperture-array were simulated with Matlab, and figures of one- and two-dimensional diffraction intensity distribution of aperture and apertures-array. The simulation results were applied to design optical system's structure parameters of a micro digital sun sensor and to determine the parameters in image processing of it. The experiments showed that simulation results of intensity distribution diffraction patterns were correct and the design results of sun sensor's optical system were resonable. The aperture-array diffraction theory provided a reliable theory for the optical system design of the sun sensor and image processing..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 294 (2006)
Quantum Optics
Teleportation of a Three-Particle GHZ State Via Three-Particle W States
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A scheme for teleporting a three-particle Greenberger-Horne-Zeilinger (GHZ) state from a sender to either of the two receivers is proposed, where the quantum channel is composed of two three-particle W states. The results show that, for such a maximally entangled quantum channel, there is still a certain probability ofA scheme for teleporting a three-particle Greenberger-Horne-Zeilinger (GHZ) state from a sender to either of the two receivers is proposed, where the quantum channel is composed of two three-particle W states. The results show that, for such a maximally entangled quantum channel, there is still a certain probability of successful teleportation if the sender performs two generalized Bell-state measurements and Hadamard operation while either of the two receivers performs the controlled-not operation and introduces an appropriate unitary transformation with the help of the other receiver's suitable measurements and classical information. The present scheme may be directly generalized to teleport an unknown n-particle GHZ state from a sender to either of the two receivers by introducing n-2 ancillary particles and performing n-2 controlled-not operations with the n-2 auxiliary particles as the target bit..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 300 (2006)
Experimental Generation of Entangled Lights from Resonating Frequency Doubler
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Following Anderson's recent investigation, the theoretical description of generating entangled light through type Ⅱ phase-matched doubling process is presented. Entanglement type, entanglement rate and relation between entanglement rate and pump power are derived. The nonlinear crystal is type Ⅱ noncritical phase-mFollowing Anderson's recent investigation, the theoretical description of generating entangled light through type Ⅱ phase-matched doubling process is presented. Entanglement type, entanglement rate and relation between entanglement rate and pump power are derived. The nonlinear crystal is type Ⅱ noncritical phase-matched KTP, and the resonant cavity is a monolithic, single ended, standing wave cavity. For the overlapping of the incident light and reflect light the entangled light cannot be retrieved from the cavity directly. They have to be retrieved in the form of a pair of coupled squeezed light, and then, squeezed light is interfered on a 50/50 optical beam splitter to restore the entangled light. The quantum entangled beams of subharmonic waves with anti-correlated amplitude-quadratures and correlated phase-quadratures are experimentally generated from a resonating frequency-doubler pumped by a subharmonic laser through a type-Ⅱ phase matching frequency-conversion. Noise power spectra of the amplitude sum and the phase difference between the entangled beams are 0.2±0.1 dB and 1±0.2 dB below the shot noise levels, respectively. Finally, the unequal entanglement rate of two quadrature is analyzed. Compared with the authors' frequently used method of generating entangled light——the optical parametric oscillator, the configuration of authors' system is relatively simple..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 305 (2006)
Thin Films
Microstructures and Photoluminescence Properties at Room Temperature of Highly Er/Yb Co-Doped ZnO Films
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Er/Yb co-doped ZnO films were fabricated by using radio-frequency reaction magnetron sputtering technique, and the influences of annealing temperature on the microstructures and photoluminescence (PL) properties of Er/Yb co-doped ZnO films were studied. The results of X-ray diffraction analysis showed that Er/Yb dopingEr/Yb co-doped ZnO films were fabricated by using radio-frequency reaction magnetron sputtering technique, and the influences of annealing temperature on the microstructures and photoluminescence (PL) properties of Er/Yb co-doped ZnO films were studied. The results of X-ray diffraction analysis showed that Er/Yb doping induced the crystallite refinement and the vanishment of preferential orientation of the ZnO films and the ZnO crystallite grain size grew with the increase of the annealing temperature. At 900 ℃, Er2O3 and Yb2O3 phases started to precipitate from the film. When the annealing temperature reached to 1000 ℃, a new phase of Zn2SiO4 due to the interfacial reaction of ZnO film with Si chip was observed. At 1200 ℃, ZnO film transited into Zn2SiO4 phase entirely. The PL measurement result indicatcd distinet PL spectra of the films about 1540 nm annealed above 900 ℃ were detected at room temperature and the maximum PL intensity was observed at 1050 ℃. The PL spectra showed typical sharp multi-peak structure characteristic owned by Er3+ ion PL spectra in crystal substrates. The effect on PL properties of the microstructure evolvement of the film was also discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 311 (2006)
X-Ray Optics
Experimental Results of Focusing Performance for the Compound High-Energy X-Ray Refractive Lenses
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The compound high-energy X-ray lens is a kind of novel refractive X-ray optical device. The latest experimental results of the focusing perfermance of the compound high-energy X-ray lens is designed with PMMA with the parameters of 40 plano-concave elementary lenses positioned in line with axial symmetry, 200 μm radiusThe compound high-energy X-ray lens is a kind of novel refractive X-ray optical device. The latest experimental results of the focusing perfermance of the compound high-energy X-ray lens is designed with PMMA with the parameters of 40 plano-concave elementary lenses positioned in line with axial symmetry, 200 μm radius of the concave surface, 0.15 nm working wavelength, 0.5 mm geometrical aperture and 8 mm length of the compound lens and 1.3 m focus length, are briefly introduced. Then the experimental setup for the focusing performance is described, and the focusing performance of the PMMA compound high-energy X-ray lens is tested under the inradiation of the 8 keV monochromatic X-ray. The experimental results are in general coincident with the calculated results..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 317 (2006)
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