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2003, 1(2) Column

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Chinese Optics Letters 第1卷 第2期

Author Affiliations
Abstract
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
In this paper, the spin-coated thin films of phthalocyanine dye are presented. Absorption spectrum of the thin film shows a comparatively broad absorption in the wavelength range 630-770 nm. Optical parameters of the thin film were measured by a spectroscopic ellipsometer system. 5-in CD-R discs made of this dye exhibit good performance with Yamaha 20-speed recorder. Jitters of land and pit are less than 30 ns, and the 3T-11T's signals show very good quality. This dye is a promising recording medium for CD-R with much higher recording speed.
160.4890 organic materials 210.4810 optical storage-recording materials 210.4590 optical disks 
Chinese Optics Letters
2003, 1(2): 02102
Author Affiliations
Abstract
Department of Dermatology, Huashan Hospital, Medical College of Fudan University, Shanghai 200040
In order to determine the appropriate treatment interval, 267 patients who underwent 3 sessions of treatment with Q-switched alexandrite laser were divided into 4 groups according to treatment interval, and their clinical responses were compared. Among them, 187 were asked about the process of pigment fading. Moreover, light and transmission electron microscopy were performed. It was noted that the clinical response of the 5-6 month interval group was significantly better than that of the 3-4 month group, but showed no significant difference from that of the 7-8 or >=9 month group. 80.21% of investigated patients stated that marked pigment fading could no longer be observed 7 months after irradiation. 4 months after irradiation, the degenerated melanosomes and cell debris were still scattered among collagen fibers, scavenged gradually by macrophage. In conclusion, an appropriate treatment interval is 5-6 months.
140.3540 lasers Q-switched 
Chinese Optics Letters
2003, 1(2): 02105
Author Affiliations
Abstract
Fiber Optic Sensing Technology Research Center, Wuhan University of Technology, Wuhan 430070
A new type of fiber optic glucose biosensor based on fluorescence quenching has been designed and its properties have been studied. Glucose can be oxidized by oxygen when glucose oxidase are used as the catalyst, therefore, the concentration of glucose can be measured by detecting the consumption of oxygen. For the detection of oxygen concentration, the ruthenium(II) complex, Ru(bpy)3Cl2, were used as the fluorescence indicator and its fluorescence lifetime were detected by lock-in technology. The detecting range of the sensor is 50-500 mg/dl and its response time is 30 seconds, showing that this kind of sensors is possible to be used in clinical diagnosis and detection.
120.3890 medical optics instrumentation 
Chinese Optics Letters
2003, 1(2): 02108
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
2 State Key Laboratory of Transient Optics Technology, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710068
Based on Fresnel-Kirchhoff diffraction theory, we set up a diffraction model of nonlinear optical media to Gaussian beam, which can interpret the Z-scan phenomenon from a new way. This theory is not only well consistent with the conventional Z-scan theory in the case of small nonlinear phase shift, but also can fit for the lager nonlinear phase shift. Numeric computations indicate the shape of the Z-scan curve is greatly affected by the value of the nonlinear phase shift. The symmetric dispersion-like Z-scan curve is only valid for small nonlinear phase shift (|Δφ0|<π), but with increasing the nonlinear phase shift, the valley of the transmittance is severely suppressed and the peak is greatly enhanced. Further calculations show some new interesting results.
190.3270 Kerr effect 190.5940 self-action effects 050.1970 diffractive optics 050.5080 phase shift 
Chinese Optics Letters
2003, 1(2): 02111
Author Affiliations
Abstract
1 Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026
2 Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
The fidelity of teleportation of continuous quantum variables can be improved by tuning the local displacement gain. We investigate the optimization of the fidelity for the teleportation of Schrodinger cat states, and of coherent states. It is found that the gain corresponding to the maximum fidelity is not equal to one for the two input states in the case of the small squeezing degree of the entanglement resource, while unity displacement gain is the best choice for teleporting arbitrary quantum states in the case of large squeezing.
270.6570 squeezed states 000.2690 general physics 230.1360 beam splitters 
Chinese Optics Letters
2003, 1(2): 02114
Author Affiliations
Abstract
1 Department of Physics, Shanghai University, Shanghai 200436
2 Key Laboratory for Quantum Information and Measurements of Education Ministry, Tsinghua University, Beijing 100084
In this paper, we derive the bright and dark photon number states for spatial interference of two or more light beams and succeed in the explanation of Young's interference experiment, and also achieve a better comprehension of the well known comment of Dirac "each photon only interferences with itself". From the fully quantum point of view, the origin of the interference fringes consists in the mode transformation and the detection of double-slit states.
030.0030 coherence and statistical optics 030.4070 modes 040.5570 quantum detectors 270.0270 quantum optics 270.1670 coherent optical effects 270.5290 photon statistics 
Chinese Optics Letters
2003, 1(2): 02118
Author Affiliations
Abstract
Department of Physics, Suzhou University, Suzhou 215006
The gradient force, as a function of position and velocity, is derived for a two-level atom interacting with a standing-wave laser field. Basing on optical Bloch equations, the numerical solutions for the gradient force f_(|_;n) (n = 0, 1, 2, 3, 4, ...) pointing in the direction of the transverse of the laser beam are given. It is shown the higher order gradient force plays important role at strong intensity (G = 64), the contribution of them can not be neglected.
140.3320 laser cooling 020.7010 trapping 
Chinese Optics Letters
2003, 1(2): 02122
Author Affiliations
Abstract
Institute of Modern Optics, Nankai University, Tianjin 300071
A novel structure of high extinction ratio multiplexer/demultiplexer with a Mach-Zehnder interferometer (MZI) and a fiber loop mirror (FLM) is proposed. The experimental results show that the extinction ratio can be enhanced about two times in comparison with the conventional MZI.
060.1810 couplers switches and multiplexers 350.2460 filters interference 
Chinese Optics Letters
2003, 1(2): 0263
Author Affiliations
Abstract
1 National Laboratory on Local Fiber-optic Communication Networks &
2 Advanced Optical Communication Systems, Shanghai Jiaotong University, Shanghai 200030
A model for calculating loss and crosstalk in WDM passive optical network based on spectral slicing is proposed in this paper. Through theoretical analysis and numerical calculation, the relationship between loss or crosstalk and the parameters of the system, such as the bandwidth of the light-source, the parameters of the multiplexer, the number of channels and the fraction of channel misalignment, was demonstrated.
060.2330 fiber optics communications 060.4250 networks 
Chinese Optics Letters
2003, 1(2): 0265
Author Affiliations
Abstract
Department of Physics, Beijing Normal University, Beijing 100875
A design method of the apodizing functions for guided-wave four-port electrooptic tunable filter (EOTF) is proposed. As an example, the specific form of Gaussian apodizing function is designed by analyzing the crosstalk performance of EOTF. Crosstalk is calculated based on the transient response of the filter to an input optical pulse. It is concluded that crosstalk level below -30 dB for 20-Gb/s data rates and 100-GHz channel spacing is achievable with presently available substrate dimensions.
060.2340 fiber optics components 
Chinese Optics Letters
2003, 1(2): 0268
Author Affiliations
Abstract
1 Institute of Optical Fiber Technology, Shanghai Jiaotong University, Shanghai 200030
2 Institute of Information Optical Engineering, Suzhou University, Suzhou 215006
The tunability of nonuniform reflection holographic filter is investigated theoretically and experimentally. It is shown that the reflection holographic filter has not only high optical density and narrow bandwidth, but also good tunability. The coupled wave theoretical model for uniform medium is compared with the model for nonuniform medium. It is identified that the coincidence of the theoretical results of the nonuniform model with the experimental results are better than that of the uniform model.
090.2890 holographic optical elements 
Chinese Optics Letters
2003, 1(2): 0271
Author Affiliations
Abstract
State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084
A volume holographic wavelet correlation processor for performing rotation invariant pattern recognition is suggested. It uses wavelet transform to get the digital edge extraction of the original object and a single circular harmonic component is used as the matched filter to get good rotation invariance. The new filter used in this method is called wavelet circular harmonic component filter (WCHCF). Simulation results validate the theory and the experiment to recognize human faces with any rotation angle shows the utility of the newly proposed method.
100.5010 pattern recognition and feature extraction 350.2460 filters interference 
Chinese Optics Letters
2003, 1(2): 0274
Author Affiliations
Abstract
1 Institute of Automation of Nanjing University of Aeronautics and Astronautics, Nanjing 210016
2 Department of Test and Control Engineering, Nanchang Institute of Aeronautical Technology, Nanchang 330034
A novel 3-D temperature field reconstruction method is proposed in this paper, which is based on multiwavelength thermometry and Hopfield neural network computed tomography. A mathematical model of multi-wavelength thermometry is founded, and a neural network algorithm based on multiobjective optimization is developed. Through computer simulation and comparison with the algebraic reconstruction technique (ART) and the filter back-projection algorithm (FBP), the reconstruction result of the new method is discussed in detail. The study shows that the new method always gives the best reconstruction results. At last, temperature distribution of a section of four peaks candle flame is reconstructed with this novel method.
110.6960 tomography 100.3010 image reconstruction techniques 120.6780 temperature 200.4260 neural networks 300.6170 spectra 
Chinese Optics Letters
2003, 1(2): 0278
Author Affiliations
Abstract
1 Department of Electronic Science and Technology, Harbin Institute of Technology, Harbin 150001
2 The Aerodynamic Academy of Chinese Aviation Industry, Harbin 150001
A newly-developed six-degree-of-freedom calibration system for the wind tunnel balances is introduced. The frame of the system, the functions and the operating principle of different parts are presented in detail. The system is composed of four parts: the automatically loading subsystem, the automatically resetting subsystem, the data-acquisition subsystem and the measurement subsystem. The results of some cell experiments proved that the system can meet the needs of the present calibration task of the balance. Through further improvement, the system can be also used to calibrate other devices with multi degree-of-freedom and measure the minute shifts, such as the guide rail of machine tool and the assembling of large parts and so on.
090.2890 holographic optical elements 120.3930 metrological instrumentation 
Chinese Optics Letters
2003, 1(2): 0282
Author Affiliations
Abstract
1 Information Optics Institute, Sichuan University, Chengdu 610064
2 Department of Physics and Materials Science, City University of Hong Kong, Hong Kong
An automatic visible spectrometer based on a non-collinear acousto-optic tunable filter (AOTF) is constructed for high-speed spectrometry. Its spectral filtering characteristics, such as relationships between the radio-frequency (RF) driving frequency and the output central wavelength, the output bandwidth and the central wavelength, its typical spectral point spread function (PSF), and so on, are studied systematically. The preliminary measurement results of AOTF spectrometer show that it is a solid-state, high-speed, easily controllable by computer-programming, rugged and compact spectroscopic device in comparison with a conventional grating spectrometer, and has the potential for widespread spectrometric applications.
120.6200 spectrometers and spectroscopic instrumentation 300.6190 spectrometers 300.6550 spectroscopy visible 160.1050 acousto-optical materials 
Chinese Optics Letters
2003, 1(2): 0285
Author Affiliations
Abstract
Short Wavelength Chemical Laser Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023
Using a microwave generator, chlorine diluted by helium was dissociated to chlorine atoms that subsequently reacted with hydrogen azide to produce the excited states of NCl(a1Δ). Meanwhile, molecular iodine with carrier gas of helium reacted with atomic chlorine to produce atomic iodine which then was pumped to excited state of I(2P1=2) by an energy transfer reaction from NCl(a1Δ). In this paper, the changes of NCl(a1Δ) and NCl(b1Σ) emission intensity is presented when I2/He is introduced into the stream of Cl/Cl2/He/HN3/NCl(a1Δ)/NCl(b1Σ). The dependences of atomic iodine I(2P1=2) on flow ratesof gases were also investigated. The optimum parameters for I(2P1=2) production are given.
140.3320 laser cooling 020.7010 trapping 
Chinese Optics Letters
2003, 1(2): 0288
Author Affiliations
Abstract
Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080
More than 6 W average power ultraviolet radiation at 355 nm was generated in LiB3O5 (LBO) crystal through the frequency mixing of the fundamental and second harmonic radiation of a Nd:YAG laser. This performance was achieved with 38% optical-to-optical conversion efficiency (532 nm to 355 nm).
140.3610 lasers ultraviolet 140.3480 lasers diode-pumped 140.3580 lasers solid-state 
Chinese Optics Letters
2003, 1(2): 0291
Author Affiliations
Abstract
1 State Key Lab of Modern Optical Instrumentation, Optical Department of Zhejiang University, Hangzhou 310027
2 Central Research Laboratory, Hamamatsu Photonics K. K., Harakuchi 5000, Hamakita-City, Shizuoka-Pref., 434-8601 Japan
A new wavelength beam combining technique for a high-power laser diode bar by using a temperature gradient heat sink has been proposed. The thermal controlling principle of the temperature heat sink has been discussed. It has been proved by experiment that the linear temperature distribution, which generates linear wavelength spread of the output beams from a LD bar, can be obtained by introducing a temperature gradient heat sink and the output beams can be focused into a relative small spot by using the Czerny-Turner beam shaping system.
140.0140 lasers and laser optics 140.2010 diode laser arrays 140.3300 laser beam shaping 
Chinese Optics Letters
2003, 1(2): 0293
Author Affiliations
Abstract
National Research Center for Optoelectronic Engineering, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083
In a practical coupling system, a cylindrical microlens is used to collimate the emission of a high power laser diode (LD) in the dimension perpendicular to the junction plane. Using passive alignment, the LD is placed in the focus of the cylindrical microlens generally, regardless of the performance of the multimode optical fiber and the LD. In this paper, a more complete analysis is arrived at by ray-tracing technique, by which the angle θ of the ray after refraction is computed as a function of the angle θ0 of the ray before refraction. The focus of the cylindrical microlens is not always the optimal position of the LD. In fact, in order to achieve a higher coupling efficiency, the optimal distance from the LD to the cylindrical microlens is dependent on not only the radius R and the index of refraction n of the cylindrical microlens, but also the divergence angle of the LD in the dimension perpendicular to the junction plane and the numerical aperture (NA) of the multimode optical fiber. The results of this discussion are in good agreement with experimental results.
140.3510 lasers fiber 
Chinese Optics Letters
2003, 1(2): 0296
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
2 Physics Department, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
High order Bragg scattering (M = 2 and M = 3) operations of the distributed feedback dye doped sol-gel silica lasers are achieved using the second harmonic output of a Nd:YAG laser as the pump. Laser linewidth of less than 0.06 nm and conversion efficiency of 0.7% for M = 3 and 11% for M = 2 are measured. Wavelength tuning of about 15 nm around the emission center has been realized by varying the intersection angle.
140.2050 dye lasers 
Chinese Optics Letters
2003, 1(2): 0299