Journals >Chinese Optics Letters
Contents
2004
Volume: 2 Issue 5
19 Article(s)
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Diffraction and Gratings
The compensability between the longitudinal and transverse mismachining tolerance of grating in the optical pick-up head
Bayanheshig d, Xiangdong Qi, Wenhao Li, and Yuguo Tang
In this paper numeric analysis is made to the influence of the longitudinal mismachining tolerance (LMT) and the transverse mismachining tolerance (TMT) of the grating in the optical pick-up head (GOPH) of VCD, DVD, and CD-ROM on the transmissivity and the intensity ratio of the auxiliary light beam to the main read-wrIn this paper numeric analysis is made to the influence of the longitudinal mismachining tolerance (LMT) and the transverse mismachining tolerance (TMT) of the grating in the optical pick-up head (GOPH) of VCD, DVD, and CD-ROM on the transmissivity and the intensity ratio of the auxiliary light beam to the main read-write light beam (IRAM) by using the general expression of diffraction efficiency obtained from the scalar diffraction theory. On solving GOPH problem, the scalar diffraction theory and the vector diffraction theory are coincident, and the scalar diffraction theory is reliable. The result shows that LMT and TMT can compensate for the inverse effect of IRAM, however, at the expense of reducing transmissivity. As far as GOPH is concerned, the goodness that LMT and TMT can be effectively compensated for is very advantageous in manufacturing of the grating..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05249 (2004)
Fiber Optics and Optical Communications
A novel dual-wavelength fiber Bragg grating and its application in fiber ring laser
Li Jiang, Dongsheng Zhang, Xingfa Dong, Guiyun Kai, and Xiaoyi Dong
A novel method for fabricating dual-wavelength fiber Bragg gratings (FBGs) by using one phase mask is developed. The method is based on a double-exposure technique. Our technique lends itself to writing gratings with controllable reflectivity and separation of two Bragg wavelengths. A grating with two equal transmissioA novel method for fabricating dual-wavelength fiber Bragg gratings (FBGs) by using one phase mask is developed. The method is based on a double-exposure technique. Our technique lends itself to writing gratings with controllable reflectivity and separation of two Bragg wavelengths. A grating with two equal transmission peaks of 20.25 dB is obtained by this method and the separation of the two Bragg wavelengths is about 0.8 nm. With the grating, we demonstrate a dual-wavelength erbium-doped fiber ring laser whose interval of the two peaks is 0.8 nm. The laser's peak powers can get 3.1 mW above and have a good stability..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05253 (2004)
Compensation for the self-steepening effects in optical fiber communication system using midway optical phase conjugation
Yang Bu, and Xiangzhao Wang
Effects of self-steepening (SS) of chirped Gaussian pulses on optical fiber communication system using midway optical phase conjugation (OPC) are analyzed. Dynamic evolution of the ultrashort pulses is simulated numerically. It is found that OPC cannot compensate for pulse waveform distortion due to SS. The initial chiEffects of self-steepening (SS) of chirped Gaussian pulses on optical fiber communication system using midway optical phase conjugation (OPC) are analyzed. Dynamic evolution of the ultrashort pulses is simulated numerically. It is found that OPC cannot compensate for pulse waveform distortion due to SS. The initial chirp of pulses and dispersion can counteract SS and improve the compensation performance for the distortion..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05256 (2004)
Temperature sensor based on PNR in Sagnac interferometer
Yuanhong Yang
A temperature sensor based on polarization non-reciprocity (PNR) in fiber-optic Sagnac interferometer (FSI) was proposed. The experimental study was made primarily and the results agree with theory well. Discussion shows that this kind of temperature sensor can achieve high precision and have great application potentiaA temperature sensor based on polarization non-reciprocity (PNR) in fiber-optic Sagnac interferometer (FSI) was proposed. The experimental study was made primarily and the results agree with theory well. Discussion shows that this kind of temperature sensor can achieve high precision and have great application potential..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05259 (2004)
An experiment of automatic PMD compensation in 40-Gb/s RZ optical communication system
Lixia Xi, Xiaoguang Zhang, Li Yu, Guangtao Zhou... and Bojun Yang|Show fewer author(s)
An experiment of adaptive polarization mode dispersion (PMD) compensation for 40-Gb/s return-to-zero (RZ) optical communication system is reported. In the experiment, degree of polarization (DOP) is used as feedback signal and particle swarm optimization (PSO) method is adopted as logic control algorithm. The compensatAn experiment of adaptive polarization mode dispersion (PMD) compensation for 40-Gb/s return-to-zero (RZ) optical communication system is reported. In the experiment, degree of polarization (DOP) is used as feedback signal and particle swarm optimization (PSO) method is adopted as logic control algorithm. The compensation time is about 200 ms, the compensated differential group delay (DGD) is up to 30 ps, and bit error rate (BER) of 10^(-9) is reached when PMD compensation is employed..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05262 (2004)
Image Processing
A new noise erosion operator for anisotropic diffusion
Chao Cai, Mingyue Ding, Chengping Zhou, and Tianxu Zhang
A noise erosion operator based on partial differential equation (PDE) is introduced, which has an excellent ability of noise removal and edge preservation for two-dimensional (2D) gradient data. The operator is applied to estimate a new diffusion coefficient. Experimental results demonstrate that anisotropic diffusion A noise erosion operator based on partial differential equation (PDE) is introduced, which has an excellent ability of noise removal and edge preservation for two-dimensional (2D) gradient data. The operator is applied to estimate a new diffusion coefficient. Experimental results demonstrate that anisotropic diffusion based on this new erosion operator can efficiently reduce noise and sharpen object boundaries..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05268 (2004)
Lasers and Laser Optics
Resonating properties of passive spherical optical microcavities
Wen Li, and Ruopeng Wang
As an optically pumped device, the lasing characteristics of a spherical microcavity laser depend on the optical pumping processes. These characteristics can be described in term of the Q factor and the optical field distribution in a microsphere. We derived analytical expressions and carried out numerical calculation As an optically pumped device, the lasing characteristics of a spherical microcavity laser depend on the optical pumping processes. These characteristics can be described in term of the Q factor and the optical field distribution in a microsphere. We derived analytical expressions and carried out numerical calculation for Q factor and optical field. The Q factor is found to be oscillatory functions of the radius of a microsphere and the pumping wavelength, and the pumpingefficiency for a resonating microsphere is much higher than that for an anti-resonating microsphere. Using tunable lasers as pumping sources is suggested in order to achieve a higher pumping efficiency. Numerical calculation on optical fielddistribution in spherical microcavities shows that a well focused Gaussian beam is a suitable incident wave for cavity quantum electrodynamics experiments in which strong confinement of optical field in the center of a microsphere is requested, but higher order spherical wave should be used instead for exciting whispering-gallery-mode (WGM) microsphere lasers, for the purpose of favoring optical energy transferring to WGM in optical microspheres..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05271 (2004)
Q-switched mode-locked diode-pumped Nd:YVO4 laser with a saturable Bragg reflector
Juan Du, Jingliang He, Jie Liu, Qiuxia Jiang... and Huitian Wang|Show fewer author(s)
We demonstrated a diode-pumped passively Q-switched mode-locked Nd:YVO4 laser by using a relaxed saturable Bragg reflector (SBR). Stable mode-locked pulse train with the repetition rate of ~230 MHz was achieved and the pulse train was modulated by the Q-switched envelope with the repetition rate of ~150 kHz. The maximuWe demonstrated a diode-pumped passively Q-switched mode-locked Nd:YVO4 laser by using a relaxed saturable Bragg reflector (SBR). Stable mode-locked pulse train with the repetition rate of ~230 MHz was achieved and the pulse train was modulated by the Q-switched envelope with the repetition rate of ~150 kHz. The maximum output of 4 W was obtained under the pump power of 13.5 W. The optical-to-optical efficiency was 30%. We also discussed the transition of each process having emerged..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05275 (2004)
Theoretical study on controlling nonlinear behaviors of a coupled-cavity VCSEL by external optical injection
Xiaofeng Li, Wei Pan, Bin Luo, Dong Ma... and Guo Deng|Show fewer author(s)
A master-slave configuration used to control the nonlinear behaviors arising in a vertical cavity surface emitting laser(VCSEL) with strong external optical feedback is established. In terms of bifurcation diagram, time and frequency domain, theinfluence of the continuous optical injection from the master VCSEL on the A master-slave configuration used to control the nonlinear behaviors arising in a vertical cavity surface emitting laser(VCSEL) with strong external optical feedback is established. In terms of bifurcation diagram, time and frequency domain, theinfluence of the continuous optical injection from the master VCSEL on the nonlinear characteristics of the slave is investigated theoretically. For relatively weak injection, the slave still keeps its intrinsic nonlinear state. With increasing the injection strength, these nonlinear behaviors evolve to periodic fluctuation, and at last are replaced by the steady-state (e.g. the critical injection parameter for steady-state is 1.2 when external cavity's reflectivity and length are 4% and 4 cm, respectively). During this evolution the bifurcation-contraction phenomena are also observed..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05278 (2004)
A unidirectional room temperature multi-wavelength fiber ring laser without isolator
Guoyong Sun, Jing Yang, Ronghui Qu, Zujie Fang, and Xiangzhao Wang
A simplified ring cavity for achieving a unidirectional room temperature multi-wavelength erbium-doped fiber ring laser without optical isolator is demonstrated. The fiber ring cavity is built in such a way that the optical fields propagating in two directions suffer different losses caused by one sampled fiber Bragg gA simplified ring cavity for achieving a unidirectional room temperature multi-wavelength erbium-doped fiber ring laser without optical isolator is demonstrated. The fiber ring cavity is built in such a way that the optical fields propagating in two directions suffer different losses caused by one sampled fiber Bragg grating. Furthermore, simultaneous multi-wavelength lasing with 0.8-nm intervals is demonstrated with sinusoidal phase modulation just before the sampled fiber Bragg grating to prevent single-wavelength lasing and unstable wavelength oscillation..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05282 (2004)
Multi-coupler side-pumped Yb-doped double-clad fiber laser
Pan Ou, Ping Yan, Mali Gong, and Wenlou Wei
The side-coupler of angle polished method, using angle-polished multimode fiber and optical adhesive, is used to efficiently pump an Yb-doped double-clad fiber laser. The maximum coupling efficiency of 78.6% is achieved by the side-coupler for a multimode fiber with a circular core of 200 um and a double-clad fiber witThe side-coupler of angle polished method, using angle-polished multimode fiber and optical adhesive, is used to efficiently pump an Yb-doped double-clad fiber laser. The maximum coupling efficiency of 78.6% is achieved by the side-coupler for a multimode fiber with a circular core of 200 um and a double-clad fiber with a 350/400 um D-shaped inner cladding. While laser diodes (LDs) with three side-couplers are simultaneously used as pump sources, maximum output power of 1.38 W and slope efficiency of 48.9% are demonstrated in the fiber laser system..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05285 (2004)
Materials
Spectroscopic and lasing characteristics of 1,3,5,7-tetramethyl-8-ethyl-pyrromethene-BF2 complex
Yizhong Yuan, Zhenrong Sun, Zuguang Yao, and Heping Zeng
The basic optical properties of the newly synthesized pyrromethene-BF2 derivative (Compound 1) were investigated systematically by its ultraviolet to visible (UV-visible) absorption, fluorescence and triplet-triplet absorption. Its lasing characteristics were measured on a dye laser system pumped by a continuous wave AThe basic optical properties of the newly synthesized pyrromethene-BF2 derivative (Compound 1) were investigated systematically by its ultraviolet to visible (UV-visible) absorption, fluorescence and triplet-triplet absorption. Its lasing characteristics were measured on a dye laser system pumped by a continuous wave Ar ion laser. The results suggest that, compared with the typical pyrromethene-BF2 dye such as P-546, Compound 1 possesses stronger fluorescence and lower triplet-triplet absorption over its fluorescence spectral region. Excellent laser properties were also observed for Compound 1. It outperforms the commercially available benchmark laser dye rhodamine 6G in laser wavelength tuning range, which proves that Compound 1 is probably a potential candidate to be developed as the all-solid-state laser material..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05288 (2004)
Optical Devices
Analysis and combined optimization of the cladding layer in outcoupling-improved top emitting OLEDs
Ligong Yang, Peng Wu, Biqin Huang, and Peifu Gu
Within the associated framework of metal-dielectric films optics and the dual-metal-mirror microcavity structure, the effect of a cladding dielectric layer on the light outcoupling efficiency of the top emitting orgainic light-emitting devices (OLEDs) is analyzed. A combined evaluation followed by detailed design and oWithin the associated framework of metal-dielectric films optics and the dual-metal-mirror microcavity structure, the effect of a cladding dielectric layer on the light outcoupling efficiency of the top emitting orgainic light-emitting devices (OLEDs) is analyzed. A combined evaluation followed by detailed design and optimization is proposed and described in detail. The analysis shows that this cladding layer affects the device's outcoupling efficiency with three different extents as the thickness of the metal layer in the multilayer cathode varying. The simulation results give a reasonable agreement with former experiment results..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05299 (2004)
Thin Films
Study on absorbance and laser damage threshold of HfO2 films prepared by ion-assisted reaction deposition
Dawei Zhang, Shuhai Fan, Weidong Gao, Hongbo He... and Haojie Sun|Show fewer author(s)
Using a new kind of EH1000 ion source, hafnium dioxide (HfO2) films are deposited with different deposition techniques and different conditions. The absorbance and the laser damage threshold of these films have been measured and studied. By comparing these characteristics, one can conclude that under right conditions, Using a new kind of EH1000 ion source, hafnium dioxide (HfO2) films are deposited with different deposition techniques and different conditions. The absorbance and the laser damage threshold of these films have been measured and studied. By comparing these characteristics, one can conclude that under right conditions, such as high partial pressure of oxygen and right kind of ion source, the ion-assisted reaction deposition can prepare HfO2 films with higher laser induced damage threshold..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05305 (2004)
Study for infrared spectroscopic ellipsometric properties of diamond films
Linjun Wang, Yiben Xia, Hujiang Shen, Minglong Zhang... and Lin Wang|Show fewer author(s)
Spectroscopicellipsometric measurements in infrared region (2.5-12.5 um) are carried out to characterize the structure and quality of diamond films grown by microwave plasma chemical vapor deposition (MPCVD) and hot filament chemical vapor deposition (HFCVD), respectively. It is found that the establishment of appropriSpectroscopicellipsometric measurements in infrared region (2.5-12.5 um) are carried out to characterize the structure and quality of diamond films grown by microwave plasma chemical vapor deposition (MPCVD) and hot filament chemical vapor deposition (HFCVD), respectively. It is found that the establishment of appropriate models has the strongest influence on the fit of ellipsometric spectra. The best fit is achieved for MPCVD film with a 77.5-nm middle layer of SiO2, and for HFCVD film with an 879-nm rough surface layer included by Bruggeman effective medium approtimation (EMA). Finally the refractive index and the extinction coefficient are calculated for both films, the results show that the film grown by MPCVD is optically much better than that grown by HFCVD at infrared wavelengths..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05308 (2004)
Holography
The reconstruction of diffractive object digital hologram at a short distance
Liyun Zhong, Yimo Zhang, Xiaoxu Lv, and Caojin Yuan
By using a spherical wave as the reference wave, we recorded the in-line phase-shifting digital hologram of the 25th element of Chinese standard No. 3 resolution test pattern, and gave the corresponding numerical reconstructed results. Some problems concerning with the digital hologram recording and reconstruction of tBy using a spherical wave as the reference wave, we recorded the in-line phase-shifting digital hologram of the 25th element of Chinese standard No. 3 resolution test pattern, and gave the corresponding numerical reconstructed results. Some problems concerning with the digital hologram recording and reconstruction of the diffractive object at a short distance are discussed. The experimental result shows that the resolution of the reconstructed image is better than 10 um, which is the limit by using this experimental arrangement..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05265 (2004)
Quantum Optics
Absorption-amplification response with or without spontaneously generated coherence effect in a four-level atomic system
Jiahua Li, Wenxing Yang, and Jucun Peng
We discuss and analyze the absorption properties of a weak probe field in a typical four-level atomic system in the presence of a spontaneously generated coherence (SGC) term. The influences of the SGC and a coherent pump field on the probe absorption-amplification are investigated. The results show that the absorptionWe discuss and analyze the absorption properties of a weak probe field in a typical four-level atomic system in the presence of a spontaneously generated coherence (SGC) term. The influences of the SGC and a coherent pump field on the probe absorption-amplification are investigated. The results show that the absorption of such a weak probe field can be dramatically enhanced due to the SGC effect. At the same time, the probe-absorption profile exhibits a two-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On the contrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved by adjusting the coherent pump field intensity in the absence of the SGC effect..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05302 (2004)
OPTICAL DATA STORAGE
Three-dimensional optical storage in fused silica using modulated femtosecond pulses
Qing Liu, Guanghua Cheng, Yishan Wang, Zhao Cheng... and Guofu Chen|Show fewer author(s)
Three-dimensional bitwise optical recording with a density of 500 Gb/cm3 in fused silica using a Ti:sapphire femtosecond laser modulated by binary digits is demonstrated. Laser pulses modulation is realized by modulating two circuits of trigger pulses signal which are used to control laser pulses trapping and switchingThree-dimensional bitwise optical recording with a density of 500 Gb/cm3 in fused silica using a Ti:sapphire femtosecond laser modulated by binary digits is demonstrated. Laser pulses modulation is realized by modulating two circuits of trigger pulses signal which are used to control laser pulses trapping and switching out from cavity, respectively. Bits are optically readout in both a parallel reading (phase-contrast) and a serial reading (confocal-type) methods. The method for modulating laser pulses can also be used in all of pulsed laser systems which operate in cavity-dumping configuration..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05292 (2004)
Optical Design and Fabrication
Study on the response characteristics of adaptive focusing system for flying optics
Xiongliang Chai, Zhaogu Cheng, and Haijun Gao
The ABCD law of parameter q for fundamental-mode Gaussian beam is deduced in this paper. The result shows that the changes of focal length and focal depth are not related to the orders of the Gaussian beam modes when focus lens moves along optical axis in a large range, indicating that the ABCD law of parameter q can bThe ABCD law of parameter q for fundamental-mode Gaussian beam is deduced in this paper. The result shows that the changes of focal length and focal depth are not related to the orders of the Gaussian beam modes when focus lens moves along optical axis in a large range, indicating that the ABCD law of parameter q can be used for any order modes. A laser focusing setup is designed, and the response characteristics of oil pressure system therein are also studied..
Chinese Optics Letters
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 5, 05295 (2004)
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