共查询到20条相似文献,搜索用时 15 毫秒
1.
A theory of optical-frequency conversion using nearly degenerate four-wave mixing (FWM) in an injection-locked semiconductor laser is presented by small-signal analysis. The bandwidth of the converted signal is determined by the relaxation resonance frequency of the laser. The greatest conversion efficiency appears when the pump-probe detuning frequency is equal to the relaxation resonance frequency. The influence of the bias of the laser, the pump power and the other injection-locking parameters on the frequency conversion efficiency is discussed. The theoretical results agree with experiments 相似文献
2.
A small-signal analysis for optical FM signal amplification by an injection-locked type semiconductor laser amplifier with consideration of the spurious intensity modulation (SIM) is presented. In general, the performance of optical FM signal amplification by a laser amplifier is affected by the value of the injection power, by the performance of the injecting laser (the master laser), and by the difference between the emission frequencies of the master and slave optical cavities. In particular, when the modulation frequency is very low, the output frequency deviation (FD) of the laser amplifier turns out to coincide with that of the master laser. However, SIM of the laser amplifier in this case is influenced by the injection conditions. A suitable definition, the ratio of the output FD to SIM to the input FD to SIM, is given to evaluate the performance of an injection-locked-type semiconductor laser amplifier 相似文献
3.
A small signal analysis is presented for optical-frequency conversion using nearly degenerated four-wave mixing (FWM) in a semiconductor laser. The nearly degenerate FWM is mainly introduced by the carrier beating at the detuning frequency of the pump and the probe waves. Generally speaking, the influence of the nonlinear gain saturation on the frequency conversion efficiency is very small compared with that of the carrier density beating. However, the conversion efficiency is damped by the nonlinear gain saturation at higher bias current. The frequency conversion efficiency and the probe transmissivity are almost symmetrical with respect to the zero detuning frequency. The bandwidth of the converted signal is governed by the relaxation resonance frequency of the laser. A definition of the conversion. The theoretical results agree with experiments 相似文献
4.
Petitbon I. Gallion P. Debarge G. Chabran C. 《Quantum Electronics, IEEE Journal of》1988,24(2):148-154
Theoretical and experimental results from an injection-locked semiconductor laser are reported. The measure deposition and size of the locking bandwidth compare favorably to those calculated using the authors' model of the injected laser. The effect of synchronization on the intensity level is pointed out. The usefulness of the technique in terms of modulation is estimated based on the behaviour, amplitude, and frequency of the relaxation oscillations which are the main limiting factor 相似文献
5.
Small signal analysis of frequency chirping in injection-locked semiconductor lasers 总被引:1,自引:0,他引:1
A theoretical and experimental investigation of frequency chirping in injection-locked semiconductor lasers under a condition of small signal modulation is presented. It shows that a substantial reduction of frequency chirping can be obtained which, however, is effective only up to modulation frequencies of the order of the locking bandwidth and is strongly dependent on the frequency detuning between master and slave. 相似文献
6.
Kuznetsov M. Verlangieri P. Dentai A.G. Joyner C.H. Burrus C.A. 《Photonics Technology Letters, IEEE》1992,4(10):1093-1095
The tuning range of the traditional tunable lasers using distributed Bragg reflection is limited by the small refractive index change that can be induced in semiconductors. The authors report the design, fabrication, and characteristics of a novel asymmetric Y-branch (AYB) tunable laser. By geometrically leveraging the index change in these laser structures, they demonstrate, using a single current control, a discrete tuning range as large as 1.0 THz, access to 24 frequency channels, and tuning rates in excess of 100 GHz/mA. AYB lasers appear promising for applications requiring wide tuning range, fast electronic frequency access, and simple low current control 相似文献
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Audio signal transmission over THz communication channel using semiconductor modulator 总被引:1,自引:0,他引:1
The first demonstration has been made of the transmission of an audio signal via a THz communication channel using a recently developed room temperature semiconductor THz modulator which is based on the depletion of a two-dimensional electron gas. A standard THz time-domain spectroscopy setup is modified to transmit signals up to 25 kHz over a 75 MHz train of broadband THz pulses. 相似文献
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Theoretical analysis of tunable wavelength conversion based on FWM in a semiconductor fiber ring laser 总被引:1,自引:0,他引:1
Pei-Li Li De-Xiu Huang Xin-Liang Zhang Jun Chen Li-Rong Huang 《Quantum Electronics, IEEE Journal of》2005,41(4):581-588
A comprehensive broad-band dynamic model of a tunable wavelength converter based on four-wave mixing (FWM) in a semiconductor fiber ring laser (SFRL) is presented. Critical factors, e.g., the material gain profile, the longitudinal variation of the optical field, the carrier density, photon density, and the broad-band spontaneous noise emission, are considered in the model. Therefore, the static and dynamic characteristics of this kind of wavelength converter can be predicted more accurately. By numerical simulation, the effects of the input signal power, injection current, the coupling coefficient of the output coupler, and the lasing wavelength on the conversion efficiency of the wavelength converter are investigated. Also, the optical pulse pattern, frequency chirp, and extinction ratio of the conjugate signal are evaluated. To widen the dynamic range of input signal power, an erbium-doped fiber amplifier (EDFA) is added into the SFRL. The characteristics of this tunable wavelength converter with an SFRL are investigated in detail. 相似文献
11.
The small-signal single-pass gain for 24 individual CO laser lines has been measured for a flowing CO-air-He laser. The vibrational-rotationalP(J)_{upsilon,upsilon'} lines considered were for rotational transitions fromJ = 10 to 16 and upper vibrational levels fromupsilon = 7 to 11. The maximum gain was observed for theP(15)_{10,9} laser line, with an average logarithmic energy gain of2.633 times 10^{-3} cm-1. 相似文献
12.
Analysis of signal voltage in a semiconductor ring laser gyro 总被引:2,自引:0,他引:2
It is expected that a semiconductor ring laser is useful as a gyro because of its tiny size. Here, we propose to use as signals voltage changes in a semiconductor ring laser corresponding to rotation. These changes in the voltage during rotation are caused by an interference of clockwise and counterclockwise laser beams inside the ring cavity. In this paper, these signal voltages are analyzed for the first time by using rate equations, It is shown that the signal voltages saturate with an increase in the injection current into a semiconductor ring laser if gain saturation is neglected. When gain saturation is considered, there exists an optimum injection current to obtain a signal voltage as large as possible. To confirm validity of this analysis, a signal voltage below laser threshold is compared with that of a semiconductor optical amplifier, and good agreement is obtained 相似文献
13.
A random PSK modulated signal generated with an optical waveguide phase modulator is used to obtain an error signal and lock the frequency of an AlGaAs semiconductor laser to the /sup 7/Rb D/sub 2/ line. The measured error signal is similar to that obtained with sinusoidal phase modulation under the same conditions. The technique could be applied to longer wavelength lasers and other types of laser that cannot be directly modulated such as fibre lasers.<> 相似文献
14.
D. George H. Fews M. McCall 《Photonics Technology Letters, IEEE》1997,9(1):49-51
We have investigated a new technique for the enhancement of a wavelength conversion system based on nearly degenerate four wave mixing in a InGaAsP DFB semiconductor laser amplifier. We report enhanced wavelength conversion over 20 nm from 1.55 /spl mu/m to 1.53 /spl mu/m using feedforward photomixing from two independent source lasers to directly modulate the semiconductor laser amplifier. We find that the wavelength conversion efficiency is enhanced by 200% using this technique. 相似文献
15.
Theoretical studies are carried out on long haul direct detection optical fiber communication systems, with inline optical semiconductor amplifier repeaters. Calculations are made of the noise, eye diagrams, and bit-error-rate characteristics of lightwave systems with optical amplifiers. Indications are given of the effect of amplifier characteristics such as spontaneous noise and signal distortion due to gain saturation on the system performance. The nonlinear process within semiconductor laser amplifiers leads generally to pulse amplitude-temporal distortions due to gain saturation. This theoretical study demonstrates that the system penalty caused by these nonlinear effects appears progressively as the optical input power at each amplifier is increased. For example, nonregenerated fiber transmission using traveling wave semiconductor laser amplifiers was simulated, and results obtained at 0.5 and 2.5 Gb/s are presented. In order to improve the system performance, the influence of structure and bulk dimensions of the amplifier cavity is also considered 相似文献
16.
An analytic expression is derived for the output signal spectrum from a semiconductor laser amplifier (SCLA) using an approach analogous to the Langevin equations of laser noise analysis. The authors present an analysis of the line broadening effects of SCLAs taking into account the effect of facet reflectivities. The signal linewidth is shown to increase with input linewidth and amplifier gain. There is an optimum facet reflectivity which gives the smallest linewidth increase. The results have significant implications in weakly coherent systems utilizing cascades of optical amplifiers 相似文献
17.
Repeated wavelength conversion of 10 Gbit/s pseudorandom non-return-to-zero signals is demonstrated using superstructure grating distributed Bragg reflector lasers operating in the 1.55-μm wavelength region. Error-free and very low-power-penalty wavelength conversion can be achieved in both first and second wavelength conversion for a fixed converted wavelength over a broad wavelength range from 1.486 to 1.573 μm (about 90-nm wide). The power penalty of the transmitted signal light through the first wavelength conversion device increases when the converted wavelength is switched from 1.544 to 1.573 μm periodically at a repetition frequency of 40 MHz. The increase in power penalty, however, is less than 6 dB even when the bit error rate is 10-12 相似文献
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Power conversion efficiency of semiconductor injection lasers and laser arrays in CW operation 总被引:1,自引:0,他引:1
In many applications it is important to optimize the power conversion efficiency of semiconductor lasers and laser arrays. A method for calculating this efficiency which takes into account temperature effects is described, and some calculated results are presented and discussed. It is found that under certain conditions, a small increase in the thermal resistance of the device can result in a large reduction of its efficiency. Temperature effects are important in high-power semiconductor lasers, and in particular in laser arrays, where low thermal resistance heat sinking may be crucial to the device operation. 相似文献
20.
It is theoretically demonstrated that the FM light output of a semiconductor laser can be detected through FM-AM conversion using an optical fiber. The analysis is made in the case of narrow-band FM and for the fundamental mode in a step-index monomode fiber. It is shown that for a 10 GHz modulation frequency, the fiber length necessary to achieve maximum demodulation lies in the range of 10 km. 相似文献