Contents
1996
Volume: 16 Issue 12
35 Article(s)
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Atmospheric Optics and Oceanic Optics
Compensation Experiment of Focused Beam Turbulence Effect
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The compensation experiment of simulated turbulence effect of focused beam is reported. Integral probability of compensation efficiency Strehl ratio is given in the sense of short exposure. The ensemble calibration of the relation between the compensation efficiency of the adaptive optics system and the turbulence coheThe compensation experiment of simulated turbulence effect of focused beam is reported. Integral probability of compensation efficiency Strehl ratio is given in the sense of short exposure. The ensemble calibration of the relation between the compensation efficiency of the adaptive optics system and the turbulence coherent length has been done..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1786 (1996)
Optical Structure of Fried′s Coherence Length in the Convective Turbulent Tank
[in Chinese], [in Chinese], and [in Chinese]
The Fried′s Coherence Length quantitatively was measured by means of two different methods in the convective turbulent tank for adaptive compensation experiments. The spectra of arrival angle fluctuations and its probability distribution were given. It was showed that the spectra of arrival angle fluctuations agreed wiThe Fried′s Coherence Length quantitatively was measured by means of two different methods in the convective turbulent tank for adaptive compensation experiments. The spectra of arrival angle fluctuations and its probability distribution were given. It was showed that the spectra of arrival angle fluctuations agreed with the theoretical prediction “-8/3” power law. The fluctuations of phase fellowed a normal distribution. The χ 2 distribution appeared to be a reasonable assumption for variance of arrival-angle fluctuations. The spectrum of arrival-angle in X axis same as the spectrum in Y axis indicated obviously that the turbulence in the tank was isotropic feature. The experimental results between the Fried's Coherence Length and temperature differences between heated-plate and cooled-plate, agreed with the similar relationship in fluid mechanics and thermodynamics experiments in the convective tank..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1790 (1996)
Holography
Locally Adaptive Clipped Model and Its Application in of Traffic Sign Recognition
[in Chinese], and [in Chinese]
The storage capacity and addressability of Hopfield model decline greatly when stored patterns are not of independence and equal number of 1, 0 state. To remove this drawback, an neural networks of locally adaptive clipped model is proposed and realized with encoding method of beam direction. This model is also appliedThe storage capacity and addressability of Hopfield model decline greatly when stored patterns are not of independence and equal number of 1, 0 state. To remove this drawback, an neural networks of locally adaptive clipped model is proposed and realized with encoding method of beam direction. This model is also applied to the recognition of traffic sign. The experimental results show that locally adaptive clipped model and the optical system performs well..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1750 (1996)
Implementation of Optical Addressed 2×2 Photonic Switch and 3 D Stacked Optical Butterfly Interconnection Network
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The optical 2×2 switching is the key part of the implementation of the optical multistage interconnection network. In this paper, a method to construct the optical addressed 2×2 switching is presented. It is based on the birefrigence property of the calcite crystal, and the PROM device is used to control the The optical 2×2 switching is the key part of the implementation of the optical multistage interconnection network. In this paper, a method to construct the optical addressed 2×2 switching is presented. It is based on the birefrigence property of the calcite crystal, and the PROM device is used to control the polarization of the input light. This photonic switching has many advantages, and it can be stacked in 3 D directions. The 3 D stacked butterfly network is easy to implement by using this switching..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1757 (1996)
Study of Converter Holographic Grating and Its Applications
[in Chinese], [in Chinese], and [in Chinese]
Concept of converter holographic grating is proposed and its structure characteristics are theorelically analysed. Three kinds of experimental device to make converter holographic grating are designed. It is proved that combining converter holographic grating with lens can produce variable angle between reference lightConcept of converter holographic grating is proposed and its structure characteristics are theorelically analysed. Three kinds of experimental device to make converter holographic grating are designed. It is proved that combining converter holographic grating with lens can produce variable angle between reference light and object light and variable size of holographic facula..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1762 (1996)
Effect of Quantization Error on the Computed Phase of Phase Shifting Measurement
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The effect of the quantization of the fringe intensity on the phase error in phase shifting measurement is formulated. An expression of the statistical relationship between the measured phase error and the fringe intensity error is presented. The expansion of the intensity error in Fourier series allows to obtain an anThe effect of the quantization of the fringe intensity on the phase error in phase shifting measurement is formulated. An expression of the statistical relationship between the measured phase error and the fringe intensity error is presented. The expansion of the intensity error in Fourier series allows to obtain an analytic expression for the variance of the phase given by a standard N sample algorithm. A numerical simulation is performed, and its result is in good agreement with the analytic one. Several factors influencing the quantization effects are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1767 (1996)
Instrumentation, Measurement and Metrology
Rebuilding Principle Formula of Optical Triangulation Method of Displacement Measurement in View of the Lambert′ Theory
[in Chinese], [in Chinese], and [in Chinese]
In view of the Lambert′ theory, the authors have rebuilt the principle formula of optical triangulation method for displacement measurement. Comparison has been made between the new formula and the old formula built on geometric optics. Using the new formula, analysis of the principle factors which affect the displacemIn view of the Lambert′ theory, the authors have rebuilt the principle formula of optical triangulation method for displacement measurement. Comparison has been made between the new formula and the old formula built on geometric optics. Using the new formula, analysis of the principle factors which affect the displacement measurement precision of optical triangulation method has been carried out. The experemental results has been reported. The methods has been suggested for decreasing and coorecting the errors..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1802 (1996)
Lasers and Laser Optics
Saturable Absorption of Cr4+:YAG and Its Performance as Passive Q-Switches
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Key absorption parameters of Cr4+:YAG are calculated based on rate equations. Pulsed Nd:YAG laser is Q-switched using Cr4+:YAG to generate 8 ns laser pulse. CW Nd:YAG laser is also Q-switched using this crystal and both period jitter and amplitude fluctuation of output pulse train are less than 5%.Key absorption parameters of Cr4+:YAG are calculated based on rate equations. Pulsed Nd:YAG laser is Q-switched using Cr4+:YAG to generate 8 ns laser pulse. CW Nd:YAG laser is also Q-switched using this crystal and both period jitter and amplitude fluctuation of output pulse train are less than 5%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1665 (1996)
Output Characteristics of Linear Cavity Erbium Doped Fiber Laser
[in Chinese], [in Chinese], and [in Chinese]
The output characteristics of linear cavity erbium doped fiber laser have been analyzed theoretically and explicitly by solving rate equations. Analytical expressions are evaluated for threshold pump power, output power, and slope efficiency of the laser under steady state conditions. The expression of minimum and optiThe output characteristics of linear cavity erbium doped fiber laser have been analyzed theoretically and explicitly by solving rate equations. Analytical expressions are evaluated for threshold pump power, output power, and slope efficiency of the laser under steady state conditions. The expression of minimum and optimum fiber length for designing a linear cavity erbium doped fiber laser has been given..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1671 (1996)
Analytical Studies on Output Characteristics of Erbium Doped Fiber Lasers
[in Chinese], [in Chinese], and [in Chinese]
Starting from the rate equations applicable to the erbium doped fiber lasers, analytical studies on erbium doped fiber lasers pumped at 980 nm and 1480 nm bands by strong pump light have been carried out. The implicit or explicit analytical expressions of some important parameters describing the output characteristics,Starting from the rate equations applicable to the erbium doped fiber lasers, analytical studies on erbium doped fiber lasers pumped at 980 nm and 1480 nm bands by strong pump light have been carried out. The implicit or explicit analytical expressions of some important parameters describing the output characteristics, such as the output power, slope efficiency, have been obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1676 (1996)
An Active Mode Locked Semiconductor Laser with a Single Mode Fiber Phase Grating External Cavity
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An active mode locked semiconductor laser with a single mode fiber photo induced refractive phase grating external cavity is described. Near transform limited ultra short optical pulses with pulse width of 15 ps, repetition rate of 1.065 GHz, and wavelength of 1.53 μm were obtained.An active mode locked semiconductor laser with a single mode fiber photo induced refractive phase grating external cavity is described. Near transform limited ultra short optical pulses with pulse width of 15 ps, repetition rate of 1.065 GHz, and wavelength of 1.53 μm were obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1681 (1996)
Spantaneous Emission of Free Electron Laser with Plane Undulator and Axial Guide Magnetic Field
[in Chinese]
Spantaneous emission of an electron in planar undulator with an axial guide magnetic field is investigated. A general expression for the emission spectrum is derived. The lineshape of the spectrum is determined by the function sinc (u) and the spantaneous emission is elliptically polarized only when γ is very large or Spantaneous emission of an electron in planar undulator with an axial guide magnetic field is investigated. A general expression for the emission spectrum is derived. The lineshape of the spectrum is determined by the function sinc (u) and the spantaneous emission is elliptically polarized only when γ is very large or observed on axis. Use of axial magnetic fields of appropriate strengths enhances the intensity of spontaneous emission spectrum, the enhancements are more marked at the principal and the lower harmonics..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1684 (1996)
Intracavity Doubling of a Q Switched Nd:S-VAP Laser Pumped by Xenon Flash Lamp
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By using xenon flash lamp as pump source, KTP as frequency doubling crystal and BDN dye film as passive Q switch, Nd:S VAP green laser generation at 0.5325 μm has been realized. The green laser output energy and pulse width were measured under the conditions of different resonator lengths and small signal transmission By using xenon flash lamp as pump source, KTP as frequency doubling crystal and BDN dye film as passive Q switch, Nd:S VAP green laser generation at 0.5325 μm has been realized. The green laser output energy and pulse width were measured under the conditions of different resonator lengths and small signal transmission of dye film. The Q switching coupling wave rate equations for intracavity doubling are given and the experiment results are in agreement with the numerial solutions of the equations..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1690 (1996)
An Improved Design Method for Diode Laser Longitudinally Pumped Solid State Lasers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A improved design method for diode longitudinally pumped solid state laser was developed based on space dependent rate equation analysis. It provides a useful guideline for optimization of the laser mode sizes and output mirror transmission simultaneously for a given pump configuration. Experimental examples are given A improved design method for diode longitudinally pumped solid state laser was developed based on space dependent rate equation analysis. It provides a useful guideline for optimization of the laser mode sizes and output mirror transmission simultaneously for a given pump configuration. Experimental examples are given for an end pumped Nd:YAG laser, showing a good agreement with the design predictions..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1695 (1996)
Frequency Stabilization of Diode Laser Pumped Nd:YVO4Lasers
[in Chinese], and [in Chinese]
We present the results on frequency stabilization of a diode laser pumped Nd:YVO 4 laser, which is locked to a resonant reference cavity by modulating the reference cavity. In the locking case, a drift rate of 75.75 kHz/s and jitter of approximately ±1 MHz were obtained.We present the results on frequency stabilization of a diode laser pumped Nd:YVO 4 laser, which is locked to a resonant reference cavity by modulating the reference cavity. In the locking case, a drift rate of 75.75 kHz/s and jitter of approximately ±1 MHz were obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1700 (1996)
Numerical Analysis of Output Mode of UR90 Unstable Ring Resonator
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, output modes of the UR90 (90° beam rotation) unstable ring resonator used chemical oxygen-iodine laser are obtained by numerical simulation calculation. The simulation included chemical kinetics, transverse gas flow and physical optics in the resonator. Distribution curves of near field intensity anIn this paper, output modes of the UR90 (90° beam rotation) unstable ring resonator used chemical oxygen-iodine laser are obtained by numerical simulation calculation. The simulation included chemical kinetics, transverse gas flow and physical optics in the resonator. Distribution curves of near field intensity and phase and far field intensity are presented with the magnification M and the distance a from the optical axis to the edge of scaper..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1704 (1996)
Nonlinear Optics
Study on Photochromic Effect in Spiro Oxazine Dye Doped Polymeric Films
[in Chinese], and [in Chinese]
A reversible strong photochromic phenomenon in spiro oxazine (SO) dye doped polyvinyl alcohol (PVA) films is reported. The absorption spectrum of the SO/PVA film shows that there are two characteristic absorption bands at 360 nm and 595 nm, which correspond to the two different molecular configurations SO 1 and SO 2, rA reversible strong photochromic phenomenon in spiro oxazine (SO) dye doped polyvinyl alcohol (PVA) films is reported. The absorption spectrum of the SO/PVA film shows that there are two characteristic absorption bands at 360 nm and 595 nm, which correspond to the two different molecular configurations SO 1 and SO 2, respectively. Then temporal behavior of the photo isomerization between the two molecular configurations is also investigated. The molecular absorption coefficients of SO1 to UV light and SO2 to the probe beam at 515 nm are found to be 1.2 cm2/J and 6×10-2 cm2/J, respectively. The life time of SO2 in dark is about 38 seconds. Spatial light modulation and UV-to-visible image conversion using this photochromic film are demonstrated experimently..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1714 (1996)
Study of Transient Characteristic of Excited State Nonlinear Absorption by Single Laser Pulse
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new method for studying excited state nonlinear absorption through measuring the temporal profile of input and output single laser pulses was presented. Using this method, the transient excited state nonlinear absorption of the solution of cadmium texaphyrin like in chloroform ((TXP)Cd) and the solution of methyl oraA new method for studying excited state nonlinear absorption through measuring the temporal profile of input and output single laser pulses was presented. Using this method, the transient excited state nonlinear absorption of the solution of cadmium texaphyrin like in chloroform ((TXP)Cd) and the solution of methyl orange are demonstrated by the ns laser pulse. The reverse saturable absorption in (TXP)Cd and the combination of saturable absorption and reverse saturable absorption in methyl orange are observed, respectively. The theoretical simulations agree well with the experiment results..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1719 (1996)
Charactersities of Magneto Fluid and Its Applitation
[in Chinese], and [in Chinese]
The relationship of magneto birefringence with ferrofluid parameters and external magnetic field is studied. On the basis that the magnetically induced birefringence relaxes to zero with a characteristic time constant propotional to the carrier viscosity, a fiber optic viscometer is established. And the initial experimThe relationship of magneto birefringence with ferrofluid parameters and external magnetic field is studied. On the basis that the magnetically induced birefringence relaxes to zero with a characteristic time constant propotional to the carrier viscosity, a fiber optic viscometer is established. And the initial experiments show its potential applications for nondestructive viscosity measurements..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1725 (1996)
Above Threshold Ionization and High Order Harmonic Generation
[in Chinese], and [in Chinese]
By solving the 1 dimensional time dependent Schrodinger equation, the above threshold ionization (ATI) and high order harmonic generation (HOHG) of atom under different laser intensity are obtained, and the relation between the ATI and HOHG is discussed. The results show that under higher laser intensity, both the ATI By solving the 1 dimensional time dependent Schrodinger equation, the above threshold ionization (ATI) and high order harmonic generation (HOHG) of atom under different laser intensity are obtained, and the relation between the ATI and HOHG is discussed. The results show that under higher laser intensity, both the ATI and HOHG have plateau and cutoff, but under lower laser intensity, the HOHG has plateau and the ATI decreases monotonically..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1730 (1996)
On the Optimal Tuning of F-P Resonator for Compression of Optical Chirped Pulse
[in Chinese], [in Chinese], and [in Chinese]
Dual Mechanism for optical chirped pulse being compressed with a F P resonator always simultaneously exists, which is the mechanism of filtering effect and dispersion effect. Dispersion of F P resonator can change the phase of wave spectrum of chirped pulse and appear as normal or extraordinary characters, depending onDual Mechanism for optical chirped pulse being compressed with a F P resonator always simultaneously exists, which is the mechanism of filtering effect and dispersion effect. Dispersion of F P resonator can change the phase of wave spectrum of chirped pulse and appear as normal or extraordinary characters, depending on the difference between the tuning wavelength of F P resonator and the optical carrier wavelength. It turns out that the optimal tuning wavelength range of F P resonator for compression of chirped pulse is a set of noncontiguous wavelength regions separated form each other with spacing of about several nm. The results here also have successfully explained the experimental results by M. Nakazawa et al in 1990, for the first time..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1734 (1996)
Optical Devices
The Analysis and Experiment of the Transformation of the Laser Beam from a Glass Ring
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new optical element called Glass Ring is introduced in this paper. It can transform laser beam into a laser beam plane. The mechanism of the laser beam plane forming is explained by the principle of multi light beams coherent interference. Some application and possible future applications of the glass ring are also iA new optical element called Glass Ring is introduced in this paper. It can transform laser beam into a laser beam plane. The mechanism of the laser beam plane forming is explained by the principle of multi light beams coherent interference. Some application and possible future applications of the glass ring are also introduced..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1809 (1996)
Analytical Solution for Passive Q Switching with Cr Ion Doped Saturable Absorber
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The behavior of passive Q-switching with a slow saturable absorber is analyzed. From the simplified rate equations for passive Q switching, the criteria for passive Q-switching using a saturable long recovery time and excited state absorption, and the analytical formulas for the peak power, pulse energy, pulse width anThe behavior of passive Q-switching with a slow saturable absorber is analyzed. From the simplified rate equations for passive Q switching, the criteria for passive Q-switching using a saturable long recovery time and excited state absorption, and the analytical formulas for the peak power, pulse energy, pulse width and energy extraction efficiency are derived. The general results have applications in the optimal design of such passive Q-switched lasers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1813 (1996)
Coupled Wave Analysis of Polarization Properties of Phase Gratings
[in Chinese], [in Chinese], and [in Chinese]
Based on the Maxwell′s equations and boundary continuity of electromagnetic fields, rigorous vector coupled wave equations of phase gratings are derived. It shows that coupling effects exist between every order diffractive wave. The polarization properties of gratings are analyzed when different polarized fields are inBased on the Maxwell′s equations and boundary continuity of electromagnetic fields, rigorous vector coupled wave equations of phase gratings are derived. It shows that coupling effects exist between every order diffractive wave. The polarization properties of gratings are analyzed when different polarized fields are incident. Experimantal results verified the theoretical analysis..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1819 (1996)
The Study of Proton Based Long Cycle Life All Solid State Electrochromic Device
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The internal factors leading to the degradation of proton based all solid state electrochromic device were discussed. Two factors were found for the degradation of EC device: in the bleaching process, water contained in WO 3 thin film would cause OH - ions to accumulate in the film and lead to an alkaline environment, The internal factors leading to the degradation of proton based all solid state electrochromic device were discussed. Two factors were found for the degradation of EC device: in the bleaching process, water contained in WO 3 thin film would cause OH - ions to accumulate in the film and lead to an alkaline environment, Wo 3 would be solvable in it and form tungstate; Electrolysis leading to the evolution of gas of hydrogen and oxygen would happen in the EC device under high voltage, and finally the film's peeling off. Through the improvement of the device's structure and the deposition technique, an good properties and long-cycle-life all-solid-state electrochromic device with ΔO.D. of 0.5 and C/B cycles beyond 106 was gained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1824 (1996)
OPTOELECTRONICS
Deep Etch Binary Optics Element
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A novel deep etch binary optics element with phase depth exceeded 2π is developed. The relationship between deep etch binary element and diffrative efficiency is analysed theoretically and simulated by computer. The preliminary results about characteristics of the deep etch binary optics element are obtained.A novel deep etch binary optics element with phase depth exceeded 2π is developed. The relationship between deep etch binary element and diffrative efficiency is analysed theoretically and simulated by computer. The preliminary results about characteristics of the deep etch binary optics element are obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1796 (1996)
Quantum Optics
Effect of Pulse Walkoff on Optical Pulse Compression Based on Cross Phase Modulation in Single Mode Fibers
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Throuth computer simulation, we have numerically investigated the effect of pulse walkoff on optical pulse compression based on cross phase modulation in the normal dispersion regime of single mode fibers. It is found that even a small walkoff between the compressed bright pulse and the dark soliton can exert non ignorThrouth computer simulation, we have numerically investigated the effect of pulse walkoff on optical pulse compression based on cross phase modulation in the normal dispersion regime of single mode fibers. It is found that even a small walkoff between the compressed bright pulse and the dark soliton can exert non ignorable influence on the bright pulse compression. Pulse walkoff not only leads to the degradation of the compression ratio and compressed peak power of the bright pulse,but also leads to a longer fiber length at which the width of the compressed bright pulse is minimum, and leads to the non-symmetry of the compressed bright pulse. An asynchronous coupling method is proposed to reduce the walkoff effect, and the results show that asynchronously coupling of the bright pulse with the dark soliton can efficiently improve the bright pulse compression relative to the synchronous coupling method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1737 (1996)
Study of Force of TEM＊01Laser on Two Level Atoms
[in Chinese], and [in Chinese]
The steady and 1st order velocity dependent vector solutions of forces for two level atom are obtained. The solutions are applied to TEM01 laser beam and analysis shows that it exists vortex force acting on the atom. On the condition of z≤z0=kw2/λ and large blue detuning δ≥Ω0≥Γ, the forces of TEM01 travelling and standThe steady and 1st order velocity dependent vector solutions of forces for two level atom are obtained. The solutions are applied to TEM01 laser beam and analysis shows that it exists vortex force acting on the atom. On the condition of z≤z0=kw2/λ and large blue detuning δ≥Ω0≥Γ, the forces of TEM01 travelling and standing wave field acting on atom are analyzed. In general, for travlling wave filed the spontaneous emission playes an important role. In the region of r≤λ, atoms are only subject ot transeverse trapping force. For standing wave field the influence of spontaneous emission can be negligible. Averaging the forces in wavelength region along the direction of z, we show that there exist transverse trapping force and damping force for velocity vrer and there has not longtudinal trapping force but has longtudinal damping force for vzez. In the region of r≤λ, there only exists transeverse trapping force as well..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1745 (1996)
Rapid Communications
Heat Transfer Coefficient of Architectural Window with Energy Efficient Coating
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The heat transfer coefficient of architectural window with energy efficient coatings is an important parameter which reflects the performance of energy efficient coatings. In this paper, a method is put forword for calculating and measuring the heat transfer coefficient of architectural windows. Some of measured resultThe heat transfer coefficient of architectural window with energy efficient coatings is an important parameter which reflects the performance of energy efficient coatings. In this paper, a method is put forword for calculating and measuring the heat transfer coefficient of architectural windows. Some of measured results are presented. it is found that optical coatings can greatly improve the energy efficiency of windows..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1832 (1996)
[in Chinese]
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1836 (1996)
External Cavity Mode Locked Multiple Quantum Well Diode Laser
[in Chinese], [in Chinese], and [in Chinese]
An external cavity mode locked multiple quantum well diode laser is reported. Its pulsewidth is 2～5 ps, wavelength tuning range is 1.52～1.57 μm, mode locking frequency is 0.5～1.0 GHz, and average output power is 1 mW. This kind of diode lasers can be used as the light source of optical communication.An external cavity mode locked multiple quantum well diode laser is reported. Its pulsewidth is 2～5 ps, wavelength tuning range is 1.52～1.57 μm, mode locking frequency is 0.5～1.0 GHz, and average output power is 1 mW. This kind of diode lasers can be used as the light source of optical communication..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 18291831 (1996)
Spectroscopy
Spectral Characteristics of Er3+Ions in Er:YLF Crystal
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The radiative transition probabilities A JJ′ , nonradiative transition probabilities ω JJ′ and fluorescence lifetimes τ J of excited levels of Er 3+ ions in YLF crystal are calculated by using the Judd Ofelt theory. On the basis of equations of fluorescent dynamics the populations w J of excited levels, dependented on The radiative transition probabilities A JJ′ , nonradiative transition probabilities ω JJ′ and fluorescence lifetimes τ J of excited levels of Er 3+ ions in YLF crystal are calculated by using the Judd Ofelt theory. On the basis of equations of fluorescent dynamics the populations w J of excited levels, dependented on doped concentrations x, are calculated too. For 4I 11/2 → 4I 13/2 transition (at wavelength of 2.7 μm), only if doped concentration is bigger than 3 at.% the population inversion can be, and the fluorescence strength and doped concentration are increased. But for 4I13/2→4I15/2 transition (at wavelength of 1.73 μm), there is optimal doped concentration for which the fluorescent strength is maximal. When the pump probability is 103～105 s-1, the xop is 1.8～3.0 at.%. The spectral characteristic parameters of Er3+ ions in YAG crystal are calculated. Based on the comparison the advantages of Er3+:YLF as a laser crystal are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1708 (1996)
Thin Films
Study on Optical Storage Performance of a Cynine Polymer Film
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A cyanine polymer coating was prepared by spin coating process on pregrooved PC substrate, and its optical storage performance was studied. The reflectance and the absorbance at 830 nm of the coating are high enough for optical storage. With optimum recording condition, 58 dB CNR was obtained. The CNR, C (carrier signaA cyanine polymer coating was prepared by spin coating process on pregrooved PC substrate, and its optical storage performance was studied. The reflectance and the absorbance at 830 nm of the coating are high enough for optical storage. With optimum recording condition, 58 dB CNR was obtained. The CNR, C (carrier signal level) have following relations with ΔR (change of relfectance of the coating before and after recording): C∝lgΔR, CNR∝lgΔR..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1773 (1996)
Phase Films for Femtosecond Lasers
[in Chinese], [in Chinese], and [in Chinese]
The phase characteristics of the femtosecond lasers have been descibed, and the ultrashort pulse laser with the phase films compensation of the dispersion and phase self modulation have been discussed. The phase films have been designed.The phase characteristics of the femtosecond lasers have been descibed, and the ultrashort pulse laser with the phase films compensation of the dispersion and phase self modulation have been discussed. The phase films have been designed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1778 (1996)
Narrowband Spectral High Reflectivity Filter Coatings Composed of Ultrathin Metallic Film and Unsymmetrical Fabry Perot Interfere Filter
[in Chinese], and [in Chinese]
A new method for designing narrowband spectral high reflectivity filters, which combines ultrathin metallic film with unsymmetrical Fabry Perot interfere filter, is proposed in this paper. The reflection filter utilizes the metallic film material that has a property of n≈k. The layer structure in visible spectrum is giA new method for designing narrowband spectral high reflectivity filters, which combines ultrathin metallic film with unsymmetrical Fabry Perot interfere filter, is proposed in this paper. The reflection filter utilizes the metallic film material that has a property of n≈k. The layer structure in visible spectrum is given. A few of formulas of the spectral reflection properties, such as reflectivity, maximum reflectivity and reflection bandwidth, is derived and is proved by experiment. A method of designing narrowband spectral high-reflectivity filter in non-visible spectrum is provided..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 12, 1781 (1996)
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