共查询到20条相似文献,搜索用时 31 毫秒
1.
We experimentally demonstrate a bistable laser diode (BLD) formed by a vertical-cavity surface-emitting laser (VCSEL) coupled to an in-plane laser (IPL) that includes a saturable absorber section. The device can be switched between its two states (corresponding to either the in-plane laser or the vertical-cavity laser being on) by injection of optical pulses. We also discuss possible applications for this device 相似文献
2.
Uenohara H. Takahashi R. Kawamura Y. Iwamura H. 《Quantum Electronics, IEEE Journal of》1996,32(5):873-883
We have simulated the static and dynamic characteristics of voltage-controlled multiple-quantum-well (MQW) bistable laser diodes. To investigate the time response of the saturable absorber under applied electric field, we performed pump-probe measurements with picosecond resolution. The obtained differential transmission signals indicate the reduction of the carrier escape time for the saturable absorber with increasing applied electric field. The field screening effect caused by spatial change of the carrier distribution is an important factor, as is phase space filling due to the photogenerated carriers. On the basis of the time response measurements, we have designed an MQW bistable laser by solving the modified rate equation including the recovery time response of the absorption saturation, A saturable absorption region narrower than 10 μm is suitable for obtaining a low threshold device. To achieve low switching power and high switching speed, it is important to optimize the bias conditions and the MQW structures. We can expect a turn-off time of less than 10 ps, and a repetition rate of over 5 GHz from the calculations 相似文献
3.
对Kuznetsov采用的速率方程加以修正,考虑了俄歇效应的影响,我们流子寿命不再作为常数处理,而写成载流子浓度的函数。由此导出了两段式双稳半导体激光器下跳阈值点载流子浓度所满足的隐函数解析表达式。通过该解析表达式确定出了器件存在双稳的必要条件。进而讨论了俄歇复合系数、吸收区偏置电流和长度等对双稳特性的影响。 相似文献
4.
Feng M. Brilliant N. A. Cundiff S. T. Mirin R. P. Silverman K. L. 《Photonics Technology Letters, IEEE》2007,19(11):804-806
We report a two-section mode-locked quantum-dot laser with an emission wavelength that is bistable with respect to applied bias on the saturable absorber region. The two stable lasing wavelengths for this device are about 1173 and 1166 nm with a power contrast ratio of over 30 dB. The largest switchable wavelength range is 7.7 nm. The optical power and pulsewidth (6.5ps) are almost identical in the two lasing modes under optimized conditions. The operation of this laser can be explained by the interplay of the spectral-hole burning and the quantum-confined Stark effect 相似文献
5.
The threshold behavior of a practical tunnel-diode bistable trigger for trapezoidal and triangular input pulses is analytically studied. The results for a wide range of slopes of pulses are compared under different circuit conditions. It is noted that for slowly varying pulses the minimum overdrive requirement is less (which causes a larger delay) and increases with an increase in the slope. 相似文献
6.
In this paper we describe a mode-locked laser in terms of traveling pulses of light. We show that the energy absorbed by a saturable absorber is a minimum if the pulselength is a minimum, and that two pulses are essentially as favorable as one if they meet at the position of the dye cell. Under steady-state pulsing conditions, however, we show that the pulses will have a width which depends on their energy. We find that for parameters appropriate to present Nd: glass experiments, the expected length is about 10-11seconds, in agreement with observations. Finally, we demonstrate the rather surprising result that a linearly dispersive medium does not broaden the mode-locked laser pulses to first order. 相似文献
7.
InGaAsP/InP CCTS双稳态激光器的纵模及偏振特性 总被引:1,自引:0,他引:1
本文给出了InGaAsP/InP CCTS双稳态激光器的模式特性。通过实验得到对双稳态激光器来说其吸收区的存在,使其对偏振及纵模的选择有一定的作用,使得TM模的输出强度在总输出中占的比例更小,及在双稳区内给出单纵模输出。 相似文献
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9.
A calculation of the influence of a transient absorber grating on the pulse parameters of a dye laser in the "colliding pulse mode-locking" (CPM) regime is given. It is shown that, compared to other passive methods, considerably shorter pulses with a more favorable stability region can be obtained. Within the stability range of single pulse operation the shortest pulses in the CPM are obtained by operating far above threshold where the saturation energy of the amplifier is much greater than that of the absorber. Deviation from an amplifier position that is symmetric with respect to the amplification of the counter-running pulses leads to different energies of the pulses and to a strong decrease of the stability range. Taking the dispersive properties of absorber and amplifier into consideration, equations for the time dependent phase of the laser pulse are established and solved by an analytical ansatz. The resulting pulse chirp is shown to be mainly dependent on the detuning of the pulse frequency from the center frequency of the saturable absorber. The estimated values for the pulse duration and the down-chirp for typical experimental conditions of a rhodamine 6G-DODCI CPM laser agree well with the measured ones. 相似文献
10.
Optical regenerative oscillation is discussed theoretically and experimentally in three types of mirrorless bistable optical devices based on the electrooptic light modulator. The devices have two feedback signals proportional to the optical output power, and the oscillation condition and oscillation frequency depend on the time constants and conversion factors for two feedback voltages and biasing phase retardation in the light modulator. Analysis is done by treating the coupled differential equations for the time dependent feedback signals. The experimental results agree with the theoretical prediction. We show also that optical monostable pulses can be generated in the three types of bistable optical devices. 相似文献
11.
Zhigang Zhang Torizuka K. Itatani T. Kobayashi K. Sugaya T. Nakagawa T. 《Quantum Electronics, IEEE Journal of》1997,33(11):1975-1981
We studied a mode-locked Cr:forsterite laser pumped by a diode pumped Nd:YVO4 laser. Both the Kerr lens mode locking and the semiconductor saturable absorber initiated mode locking have been demonstrated. Using our measured dispersion data of the forsterite crystal, together with our dispersion compensation technique, we obtained 20-fs pulses for the pure Kerr lens mode locking and 36-fs pulses for semiconductor saturable absorber initiated mode locking, respectively 相似文献
12.
本文对双区共腔半导体双稳态激光器在电注入下的稳态及瞬态特性进行了计算机模拟,这种模型产生双稳和自脉动现象的机制是不均匀电注入本征可饱和吸收特性,我们研究了与可饱和吸收有关的几个参数r、ξ、J_1、J_2对双稳及自脉动现象的影响. 相似文献
13.
Thoen E.R. Koontz E.M. Jones D.J. Kartner F.X. Ippen E.P. Kolodziejski L.A. 《Photonics Technology Letters, IEEE》2000,12(2):149-151
Picosecond pulses are produced using a semiconductor saturable absorber mirror in a laser based on an Er-Yb codoped planar waveguide amplifier. Continuous-wave mode-locking (CWML) with 9.8-ps pulses is obtained at repetition rates up to 100 MHz. With intracavity spectral filtering, saturable pulsewidths of 1 ps are achieved, and tunable picosecond pulses are obtained from 1534 to 1553 nm. Absorber characterization suggests that two-photon absorption within the saturable absorber mirror influences the CWML stability 相似文献
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15.
In this paper, we discuss pulse dynamics in harmonically mode-locked semiconductor lasers and present the conditions necessary for stability. In a laser mode-locked at the Nth harmonic, the pulse energy fluctuations have (N+1) different modes of relaxation oscillations. Different modes correspond to different patterns for the energy fluctuations in the N different pulses inside the laser cavity. In the higher order relaxation oscillation modes, the energy fluctuations are negatively correlated in different pulses inside the laser cavity, and these modes can cause instability. Gain saturation on time scales of the order of the pulse width (dynamic gain saturation) stabilizes pulse energy fluctuations with respect to relaxation oscillations. The precise limits on the stable operating regime depend on the gain dynamics at both slow and fast time scales. We also discuss harmonic mode-locking in the presence of a slow saturable absorber. Dynamic loss saturation in a saturable absorber can work against dynamic gain saturation and limit the stability range for harmonic mode-locking. 相似文献
16.
We report stabilization of a thulium-holmium codoped fiber soliton laser with a saturable absorber based on carbon nanotubes. The laser generates transform-limited 750-fs pulses with 0.5-nJ energy. 相似文献
17.
We propose a technique for achieving mode-locking at very high repetition rates more than terahertz with high output power using a distributed-Bragg-reflector (DBR) laser, including an intracavity saturable absorber. This method is based on harmonic passive mode-locking at high gain levels and the selectivity of harmonic numbers related to the spectrum-filtering property of the intracavity Bragg reflector. Transform-limited pulses at repetition rates from 500 GHz to 1.54 THz were generated with an output power exceeding 15 mW. We studied stability of harmonic pulses by using conventional self-consistent mode-locking equations. We also discuss the effect of the spectrum-filtering properties of the intracavity Bragg reflector to the characteristics of mode-locked pulses 相似文献
18.
A novel two-mode bistable laser diode (TMBLD) with an asymmetric cavity configuration is proposed and analyzed. It consists of a gain region, a saturable absorber region, and a set of mode-selective mirrors (or filters). These elements are arranged such that the saturable absorber acts as an intracavity loss for one mode and a bleachable absorber external to the cavity of the other mode. Both modes share the same gain medium and compete for the same gain. Bleaching of the absorber leads to a switching of the modes and possible bistability. This two-mode bistability results from the complementary processes of mode competition in the gain section and the mode-dependent effective cross section of the saturable absorber. A rate equation analysis of the device indicates that a switching time less than 200 ps and a modulation rate over 3 Gb/s should be obtainable 相似文献
19.
Measurements on multielectrode distributed feedback (DFB) lasers without a saturable absorber reveal the existence of a self-pulsation (SP) regime. In this regime, the laser remains in the same single-longitudinal mode with simultaneous intensity and frequency modulation. The laser spectrum is similar to that of a current-modulated single-mode laser. At the up-limit of the SP regime, the behavior between the output power and the injection current becomes bistable. In one branch of the bistable loop, the SP laser presents a very large spectrum without distinguishable peaks, a kind of chaotic state with coherence collapse. A qualitative explanation based on the effective differential gain is given for the origin of SP and associated phenomena in these lasers 相似文献