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Fiber Optics and Optical Communications
High extinction ratio multiplexer/demultiplexer with a Mach-Zehnder interferometer and a fiber loop mirror
Yonglin Huang, Jie Li, Guiyun Kai, and Xiaoyi Dong
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.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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0263 (2003)
Study on loss and crosstalk in WDM passive optical network based on spectral slicing
Shaofeng Qiu, and Ge Fan
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 ofA 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0265 (2003)
The design of the apodizing functions for guided-wave EOTF
Jing Zhou
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 inpA 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0268 (2003)
Image Processing
Rotation invariant pattern recognition with a volume holographic wavelet correlation processor
Wenzhao Tan, Qingzeng Xue, Yingbai Yan, and Guofan Jin
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 filteA 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0274 (2003)
3-D flame temperature field reconstruction with multiobjective neural network
Xiong Wan, Yiqing Gao, and Yuanmei Wang
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.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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0278 (2003)
Lasers and Laser Optics
Experimental study on the system of Cl/Cl2/He/HN3/I2
Liping Duo, Shukai Tang, Jian Li, Xiangde Min... and Bailing Yang|Show fewer author(s)
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 excitedUsing 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0288 (2003)
High-average power THG of a diode-pumped Nd:YAG laser at 355 nm generated by LiB3O5 crystal
Yong Bi, Yan Feng, Huarong Gong, Hongbo Zhang, and Zuyan Xu
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).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)..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0291 (2003)
Beam combining of a high-power laser diode bar on a temperature gradient heat sink
Xiang Wu, Zi Ye, Zukang Lu, Yoshihiro Takiguchi... and Hirofumi Kan|Show fewer author(s)
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 wavA 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0293 (2003)
Optimal distance from high power laser diode to cylindrical microlens in a coupling system
Xiaowei Wang, Xiaoyu Ma, Jianwei Xiao, Gaozhan Fang... and Bin Liu|Show fewer author(s)
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 oIn 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0296 (2003)
High order operation of distributed feedback dye-doped sol-gel silica laser
Xiaolei Zhu, and Dennis Lo
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 tuHigh 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0299 (2003)
Materials
Novel phthalocyanine thin film for compact disc recordable
Yongyou Geng, Donghong Gu, Yiqun Wu, and Fuxi Gan
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 exhibiIn 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 02102 (2003)
Medical Optics and Biotechnology
Response of nevus of Ota to Q-switched alexandrite laser according to treatment interval
Zhong Lu, Junpang Chen, Xiasheng Wang, Lihua Fang... and Wen Huang|Show fewer author(s)
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,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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 02105 (2003)
Design and properties study of fiber optic glucose biosensor
Desheng Jiang, Er Liu, Xing Chen, and Jun Huang
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 detA 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 02108 (2003)
Nonlinear Optics
Analyses and computations of asymmetric Z-scan for large phase shift from diffraction theory
Liyong Ren, Baoli Yao, Xun Hou, Liren Liu, and Changhe Zhou
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 forBased 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 02111 (2003)
Holography
Tunability of nonuniform reflection holographic filter
Shanhong You, Xinwan Li, Jianhong Wu, Zongmin Yin, and Minxue Tang
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 modThe 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0271 (2003)
Quantum Optics
Improving the fidelity of continuous-variable quantum teleportation by tuning displacement gain
Jinming Liu, Jian Li, and Guangcan Guo
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 onThe 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 02114 (2003)
The bright and dark photon number states in Young's interference experiment
Weihan Tan, and Qizhi Guo
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". 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 02118 (2003)
Resonant gradient force on atom interacting with laser field
Jianxing Fang, Xianfeng Chen, Shiqun Zhu, and Rong Zhang
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 arThe 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 02122 (2003)
Instrumentation, Measurement, and Metrology
Research on six-degree-of-freedom calibration system for wind tunnel balances with a collimated laser beam
Zhigang Fan, Jin He, Baojun Zuo, Runshun Li... and Milin Dong|Show fewer author(s)
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 subA 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0282 (2003)
A high-speed automatic spectrometer based on a solid-state non-collinear acousto-optic tunable filter
Jianhua Zhu, and Andrew Y. S. Cheng
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 centAn 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..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 1, Issue 2, 0285 (2003)