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Contents
2003
Volume: 22 Issue 1
18 Article(s)
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Research Article
STUDY ON THE RAMAN SPECTRA OF GaP NANORODS SYNTHESIZED WITHIN CARBON NANOTUBE TEMPLATES
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The Raman spectra of GaP nanorods grown in carbon nanotube templates have been reported. The red shifts of the TO and LO modes were observed due to phonon confinement effect in GaP nanorods. The measured red shifts range from 2 to 10cm -1 depending on the size of the measured nanorods. It has been found that the polariThe Raman spectra of GaP nanorods grown in carbon nanotube templates have been reported. The red shifts of the TO and LO modes were observed due to phonon confinement effect in GaP nanorods. The measured red shifts range from 2 to 10cm -1 depending on the size of the measured nanorods. It has been found that the polarization properties, which cannot be well explained by the selection rules of single nanorod, result from the direction disorder of nanorods in the measured area. The more the disorder is, the weaker the directionality of polarization properties is. The decrease of the Raman frequency of the TO and LO mode of the nanorods with the increasing power of the exciting laser suggests that the heating effect of the nanorods is far stronger than the bulk material. In addition, the saturation and then decrease of the Raman intensity with the increasing laser power indicate the rapid increase of the defects in the nanorods exposed to a strong exciting laser..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 1 (2003)
RAMAN SPECTROSCOPY STUDY ON LO PHONON-PLASMON COUPLED MODE IN GaN THIN FILMS
[in Chinese], and [in Chinese]
A series of Si doped GaN thin films grown on sapphire substrate were measured by Raman spectroscopy. Both high-and low-frequency branches of the longitudinal-optical (LO) phonon and plasmon coupling modes (LPP modes) were resolved. With the increasing of doping level, the LPP mode shifts toward higher frequency. The twA series of Si doped GaN thin films grown on sapphire substrate were measured by Raman spectroscopy. Both high-and low-frequency branches of the longitudinal-optical (LO) phonon and plasmon coupling modes (LPP modes) were resolved. With the increasing of doping level, the LPP mode shifts toward higher frequency. The two branches in each spectrum were independently lineshape-fitted based on scattering analysis, and plasmon frequency and damping constant were obtained, thus the free carrier concentration and mobility could be deduced. The carrier concentration derived from each branch of the single spectrum coincidences with each other, and it is also consistent with infrared (IR) reflection and Hall results. The mobility from the low branch fitting is in agreement with the IR values, and is about half values of the Hall mobility, which is close to the conduction drift mobility in the regime of ionized impurity scattering. The high branch mobility is even smaller, which implies some additional scattering effect..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 8 (2003)
SPECTROSCOPIC ELLIPSOMETRY STUDIES OF BaxSr(1-x)TiO3 MULTILAYER STRUCTURE
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Ba xSr (1-x)TiO 3 single layer and graded multilayer structure films (Ba 0.7Sr 0.3TiO 3, Ba 0.8Sr 0.2TiO 3, Ba 0.9Sr 0.1TiO 3, BaTiO 3) deposited on si(100) substrate were prepared by sol-gel technique. The variable angle spectroscopic ellipsometric spectra of the Ba xSr (1-x)TiO 3 multilayer structure film were obtainBa xSr (1-x)TiO 3 single layer and graded multilayer structure films (Ba 0.7Sr 0.3TiO 3, Ba 0.8Sr 0.2TiO 3, Ba 0.9Sr 0.1TiO 3, BaTiO 3) deposited on si(100) substrate were prepared by sol-gel technique. The variable angle spectroscopic ellipsometric spectra of the Ba xSr (1-x)TiO 3 multilayer structure film were obtained in the spectral range of 380～800nm, and the thickness and refractive index of the Ba xSr (1-x)TiO 3 multilayer structure film were determined for the first time. The results show that the thickness of multilayer structure film from ellipsometric spectra is consistent with that from RBS, and the refractive index of BaTiO 3 film in multilayer is much larger than that in single layer, but closer to that in single crysal..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 13 (2003)
THERMAL AND OPTICAL ANALYSIS OF MAGNETO-OPTICAL RECORDING MULTILAYER FILM SYSTEM
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Optical matrix method was used to analyze the magneto-optical response, light intensity distribution and Joule loss distribution for a magneto-optical multilayer thin film system. Three-dimensional finite element method was applied to determine the temperature profile in the MO disk when it was exposed with a laser beaOptical matrix method was used to analyze the magneto-optical response, light intensity distribution and Joule loss distribution for a magneto-optical multilayer thin film system. Three-dimensional finite element method was applied to determine the temperature profile in the MO disk when it was exposed with a laser beam. The combination of the optical matrix method and finite element method can be used to design the MO disk..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 18 (2003)
STRUCTUREAL AND OPTICAL PROPERTIES OF PbZr0.5Ti0.5 O3/La0.5Sr0.5CoO3 MULTILAYER THIN FILMS PREPARED BY CHEMICAL SOLUTION ROUTES
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
La 0.5Sr 0.5CoO 3(LSCO)thin films were deposited on Si substrate by metalorganic chemical liquid deposition (MOCLD). PbZr 0.5Ti 0.5O 3(PZT)were deposited on LSCO thin films by sol-gel process. X-ray diffraction investigation shows that PZT/LSCO multilayer thin films are polycrystalline with preperential (110)-orientatiLa 0.5Sr 0.5CoO 3(LSCO)thin films were deposited on Si substrate by metalorganic chemical liquid deposition (MOCLD). PbZr 0.5Ti 0.5O 3(PZT)were deposited on LSCO thin films by sol-gel process. X-ray diffraction investigation shows that PZT/LSCO multilayer thin films are polycrystalline with preperential (110)-orientation and contain perovskite phase only. The grain diameter of PZT was estimated to be about 50～80nm by Scherrer's equation. Atomic force microscopy measurement shows that the films have smooth surface with RMS<5nm. Raman spectrum was used to study the structural property of PZT/LSCO thin films. The optical properties of the films were measured by spectroscopic ellipsometry in the wavelength range of 400～1700nm. Lorentz model was used to express the optical properties of PZT and LSCO thin films. Optical constants (refractive index n and extinction coefficient k) of the PZT and LSCO films were obtained..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 23 (2003)
Te ION VACANCY RESONANCE LEVEL IN Hg1-xCdxTe MATERIALS
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The MOVPE Hg 1-xCd xTe epitaxial film, LPE Hg 1-xCd xTe epitaxial film and Hg 1-xCd xTe bulk wafers grown by ACRT-Bridgman and Te solvent methods were measured by means of Raman microscopy in the room temperature. In all the experimental specimen, the micro-Photoluminescence emission centered above the bottom of Hg 1-xThe MOVPE Hg 1-xCd xTe epitaxial film, LPE Hg 1-xCd xTe epitaxial film and Hg 1-xCd xTe bulk wafers grown by ACRT-Bridgman and Te solvent methods were measured by means of Raman microscopy in the room temperature. In all the experimental specimen, the micro-Photoluminescence emission centered above the bottom of Hg 1-xCd xTe conduction band about 1.5eV were observed for the first time. It is confirmed that the micro-photoluminescence was induced by the Te ion vacancy resonance level..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 27 (2003)
SIZE EFFECT ON OPTICAL EFFECT IN Cr-Ag GRANULAR FILMS
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A series of Cr xAg 1-x(x=19,28,36) samples were prepared by ion beam co-sputtering and post-annealed in vacuum at different temperatures for one hour. The structure, surface topography and optical properties of the samples for different annealing temperatures were studied by using X-ray diffraction, AFM and optical meaA series of Cr xAg 1-x(x=19,28,36) samples were prepared by ion beam co-sputtering and post-annealed in vacuum at different temperatures for one hour. The structure, surface topography and optical properties of the samples for different annealing temperatures were studied by using X-ray diffraction, AFM and optical measurement. Results show that the optical properties are closely related to the particle size..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 31 (2003)
STUDY ON PERIODICAL POLARIZATION CHARACTERISTICS OF NEAR-STOICHIOMETRIC MgO-DOPED LiNbO3 CRYSTAL
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The fine near-stoichioment MgO-doped LiNbO 3 crystals were fabricated by the vapor transport equilibration and the dependence of the switch field on / ratio was systematically investigated. The results show that the switch field for 180° ferroelectric domain reversal in the near-stoichioment Mg:LiNbO 3 crystal decThe fine near-stoichioment MgO-doped LiNbO 3 crystals were fabricated by the vapor transport equilibration and the dependence of the switch field on / ratio was systematically investigated. The results show that the switch field for 180° ferroelectric domain reversal in the near-stoichioment Mg:LiNbO 3 crystal decreases as / ratio incrwases. 180° domain reversal in the 1.0mm near-stoichiometric Mg:LiNbO 3 samples is successfully achieved by using 3.5kV/mm switch field. A reasonable explanation for experimental results is given, which is based on the Li-site vacancy point defect model..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 35 (2003)
SYUDY ON THE MICRO-MECHANISM OF MG-DOPED LITUIUM NIOBATE CRYSTALS AGAINST PHOTOREFRACTION
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The ultraviolet-visible and infrared absorption spectra of Fe 2O 3 and MgO co-doped lithium niobate (LiNbO 3) crystals were studied. It was found that some Fe 2+ ions were still in Li-sites though Fe 3+ ions changed their site occupation from Li-sites to Nb-sites while the doping concentration of MgO was above the threThe ultraviolet-visible and infrared absorption spectra of Fe 2O 3 and MgO co-doped lithium niobate (LiNbO 3) crystals were studied. It was found that some Fe 2+ ions were still in Li-sites though Fe 3+ ions changed their site occupation from Li-sites to Nb-sites while the doping concentration of MgO was above the threshold (the first threshold). Defect chemical analysis shows that the amount of Fe 2+ ions will decrease as the doping concentration of Mg increases, and when the doping concentration reaches a suitable value (the second threshold) all Fe 2+ ions in Li-sites will diminish. It is expected that LiNbO 3 crystal doped with the second threshold will have an excellent ability to resist laser induced optical damage. This phenomenon is called as double thresholds effect..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 40 (2003)
THE STUDY OF A AUTO ELLIPSOMETER SYSTEM BY USING A TWO-DIMENSIONAL CCD ARRAY DETECTOR
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new type of CCD ellipsometer was designed and constructed to study the optical properties of materials in 5000～10000 angstrom wavelength range. In the system, the polarizer are driven by a stepping motor that have hollow shafts. The traditional spectroscopic monochromator and photomultiplier were replace by a two-dimA new type of CCD ellipsometer was designed and constructed to study the optical properties of materials in 5000～10000 angstrom wavelength range. In the system, the polarizer are driven by a stepping motor that have hollow shafts. The traditional spectroscopic monochromator and photomultiplier were replace by a two-dimensional Si-Based CCD array detector and an integrated grating consisting of three sub-gratings to avoid mechanical transmission, vibration problems and scanning grating entirely. It makes the system simple and reliable, and shorten the time of measurement greatly. The system adopted the technique of arranging CCD Spectrometer at the back. Thus, a series of problems were investigated and solved including the optical principle, instrument design, system calibration, spectra measurement and data analysis. The results from the measured spectra of the complex refractive index for a gold-film sample are presented. It well agrees with the value based on the Drude theory..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 45 (2003)
HYPER-RAMAN AND SURFACE ENHANCED HYPER-RAMAN SPECTRA OF BENZENE, PYRIDINE AND PYRAZINE
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The hyper-Raman and surface enhanced hyper-Raman spectra of benzene, pyridine and pyrazine were calculated by ab initio method. The results of theoretical calculation and experiments were compared. The molecular dipole moments, the polarizabilities, and hyper-polarizabilities were calculated by using density functionalThe hyper-Raman and surface enhanced hyper-Raman spectra of benzene, pyridine and pyrazine were calculated by ab initio method. The results of theoretical calculation and experiments were compared. The molecular dipole moments, the polarizabilities, and hyper-polarizabilities were calculated by using density functional theory (DFT) methods based on Gaussian 98. The dipole moment and polarizability derivatives were provided automatically by Gaussian 98, but the hyper-polarizatibily derivatives were determined by a finite difference method. To make sure the accuracy of this method, it was used to calculate the infrared (IR) and Raman spectra, and the results are in agreement with the analytical results provided by Gaussian 98. The methods for calculating spectra of IR, Raman, surface enhanced Raman scattering (SERS), hyper-Raman scattering (HRS), and surface enhanced hyper-Paman scattering (SEHRS) of molecules were built up based on ab initio and the finite difference method..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 51 (2003)
SIMULATION STUDY FOR OPTICAL FILTER THIN-FILM DEPOSITION MONITORING
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The simulation study of the filter's optical character affected by the In-situ optical monitoring the layer thickness and its deviation during deposition process for the optical narrow band-pass filter thin film was reported. Both of the ideal monitor trace and the simulation of optical parameters distributing curvThe simulation study of the filter's optical character affected by the In-situ optical monitoring the layer thickness and its deviation during deposition process for the optical narrow band-pass filter thin film was reported. Both of the ideal monitor trace and the simulation of optical parameters distributing curve of the 4-cavity DWDM filter were given. The simulation results are very useful in the practice of high quality optical filter thin film deposition. The filters are designed to meet specific 100GHz,200GHz DWDM and CWDM bandwidth requirements, and the three and four cavity narrow band-pass filters are produced for the industry application..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 56 (2003)
INVESTIGATIONS ON THE INFRARED SPECTROMETRIC ELLIPSOMETRY OF PbZr0.52Ti0.48O3 THIN FILMS
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
PbZr 0.52Ti 0.48O 3(PZT) thin films were grown on Pt/Ti/SiO 2/Si substrates by RF-magnetron sputtering method. X-ray diffraction analysis shows that the PZT thin films annealed are polycrystalline. Ellipsometric spectra of PZT thin films were measured by using infrared spectrometric ellipsometry in the wavelength rangePbZr 0.52Ti 0.48O 3(PZT) thin films were grown on Pt/Ti/SiO 2/Si substrates by RF-magnetron sputtering method. X-ray diffraction analysis shows that the PZT thin films annealed are polycrystalline. Ellipsometric spectra of PZT thin films were measured by using infrared spectrometric ellipsometry in the wavelength range of 2.5～12.6μm. The classical dispersion relation is used in the fitting for the PZT thin films, and the optical constants and thickness of the thin films were obtained. The thicknesses for the as-deposited PZT and annealed PZT thin films are 454.2nm and 450.3nm, respectively. The effective static charge obtained is |q|=1.769±0.024, which reveals that the charge transfer is not complete in the PZT thin films..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 59 (2003)
RESOLUTION IMPROVEMENT OF RAMAN DEPTH PROFILE
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The resolution ability of confocal Raman microscopy on the depth direction was theoretically discussed, and the response equation of confocal Raman microscopy on the depth direction was obtained by using properly approximation. A simply convolution model of thin sample (just like semiconductor film) was designed. BasedThe resolution ability of confocal Raman microscopy on the depth direction was theoretically discussed, and the response equation of confocal Raman microscopy on the depth direction was obtained by using properly approximation. A simply convolution model of thin sample (just like semiconductor film) was designed. Based on the confocal Raman spectrometer and depth profile method, the character of crystalline phase in laser recrystallized poly-Si thin films was researched. By using the deconvolution algorithm, the higher resolution structure distribution on depth direction of the film was obtained , and nano-crystalline phase was discovered locating only in the middle of thin film..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 63 (2003)
RECONSTRUCTION OF OPTICAL COHERENCE TOMOGRAPHY IMAGE BASED ON MONTE CARLO METHOD
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A method for improving the quality of the picture based on Monte Carlo simulation of imaging was presented. The point-spread-function needed by the simulation was achieved by Monte Carlo simulation of light propagation in bio-tissue. A raw picture by OCT of porcine tissue was reconstructed. The reconstructed picture haA method for improving the quality of the picture based on Monte Carlo simulation of imaging was presented. The point-spread-function needed by the simulation was achieved by Monte Carlo simulation of light propagation in bio-tissue. A raw picture by OCT of porcine tissue was reconstructed. The reconstructed picture has a better transversal resolution..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 68 (2003)
(Ba0.5Sr0.5)TiO3 THIN FILM'S PREPARATION AND IT'S ELECTRIC CHARACTERISTICS
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Ba 0.5Sr 0.5)TiO 3 ferroelectric thin films with pure perovskite structure and good dielectric and insulating properties were prepared by Sol-Gel processing. It was found that the purity and crystallinity and dielectric constant of (Ba 0.5Sr 0.5)TiO 3 ferroelectric thin films increased and the leakage current density dBa 0.5Sr 0.5)TiO 3 ferroelectric thin films with pure perovskite structure and good dielectric and insulating properties were prepared by Sol-Gel processing. It was found that the purity and crystallinity and dielectric constant of (Ba 0.5Sr 0.5)TiO 3 ferroelectric thin films increased and the leakage current density decreased with the increase of temperature. Films treated at 750℃ for 1h showed good and stable properties with a dielectric constant of 250 and a dielectric loss of 0.030 and a leakage current density of 6.9×10 -8A/cm2. The high dielectric constant, low dielectric loss and leakage current density may originate from the good Purity and crystallinity of the films. The J-U characteristics of films indicated that the conduction of the films obeyed the mechanism of the space-charge-limited injection model..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 71 (2003)
STUDY OF 100GHz NARROW BANDPASS DWDM FILTERS IN THE FIBER OPTICAL COMMUNICATION
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A three cavities 100GHz narrow band pass filer was designed and simulated according to the theory of dielectric Fabry-Perot filter. With the help of the Advanced Plasma Aided Deposition and an optical monitoring system, a DWDM filter was coated on the F7 substrate. And problems regards grinding, polishing etc. were solA three cavities 100GHz narrow band pass filer was designed and simulated according to the theory of dielectric Fabry-Perot filter. With the help of the Advanced Plasma Aided Deposition and an optical monitoring system, a DWDM filter was coated on the F7 substrate. And problems regards grinding, polishing etc. were solved. This device could be used in the optical communication or the areas related to information technology..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 75 (2003)
EFFECTS SPUTTERING Ar PRESSURE ON THE OPTICAL CONSTANTS OF Si/Ge MULTILAYERS
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The optical constants of Si/Ge multilayers, which prepared by magnetron sputtering system, have been measured by spectroscopic ellipsometry. The measured photo energy range is from 1.5eV to 4.5eV. The effects of sputtering Ar pressure on optical sonstants of Si/Ge multilayers have been analyzed. The results show that tThe optical constants of Si/Ge multilayers, which prepared by magnetron sputtering system, have been measured by spectroscopic ellipsometry. The measured photo energy range is from 1.5eV to 4.5eV. The effects of sputtering Ar pressure on optical sonstants of Si/Ge multilayers have been analyzed. The results show that the optical constants of Si/Ge multilayers increase with Ar pressure increasing in different degree within lower energy range, but the effects of Ar pressure are no more obvious in higher energy range. The peak positions of the complex dielectric functions and refractive index shift to lower energy direction with Ar pressure increasing. However, the changes of the peak positions of the extinction coefficient are very small, and their values increase with Ar pressure increasing..
Journal of Infrared and Millimeter Waves
- Publication Date: Feb. 01, 2003
- Vol. 22, Issue 1, 77 (2003)
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