与光探测器单片集成双稳半导体激光器的特性

利用光输出反馈泵浦方式,首次观测到PD/LD单片集成型光学双稳态。电路简单、稳定性好;双稳范围的宽度可根据需要在很大范围内调节。利用半导体激光器的速率方程理论计算了这类双稳激光器的稳态行为,发现实验结果和理论计算符合的很好。     

Magnetically programmable bistable laser diode with ferromagneticlayer

A new design of bistable laser diode, which consists of a gain section, absorption section, and nonreciprocal section, is proposed. The nonreciprocal section is made of a semiconductor optical amplifier covered by a ferromagnetic layer. The nonreciprocity of magneto-optical effect significantly modifies a photon density distribution in the laser cavity and enlarges a width of hysteresis loop of bistable laser diode. The bistability can be switched on or off by reversing magnetization of the ferromagnetic layer     

Large optical bistability and self pulsations in three section DBRlaser diode

A bistable operation with a hysteresis of 24 mA in the power-current curve of a three section DBR laser is reported. The laser threshold at increasing current is 51 mA while in the opposite direction the laser action is sustained down to 27 mA. The same effect was observed by monitoring the laser threshold through the Bragg and phase section currents. In a large part of the current range which corresponds to the bistable laser operation, strong self pulsations have been observed at frequencies between 1.5 GHz and 3.5 GHz with an amplitude of up to 31.4 dB     

集成双稳半导体激光器输出光强的线性稳定性分析

从速率方程出发,利用线性稳定性分析方法,分析了单片集成双稳半导体激光器输出光强的稳定性。结果表明此类双稳半导体激光器具有很大的双稳范围。     

The effect of electronic feedback on semiconductor lasers

Negative electronic feedback (EFB) has a strong effect on the performance of a bistable laser diode amplifier and on injection-locked lasers. Negative EFB drastically reduces the switching-up input power level and the hysteresis in the input-output power characteristic and in the tuning curves of the bistable laser amplifier. Furthermore, negative EFB leads to a reduction in the time delay associated with optical switching in diode laser amplifiers. This provides a means of enhancing the versatility of the proposed system in some potential applications. For an injected-locked laser, negative EFB achieves a broadening in the locking bandwidth and its dynamically stable region     

基于微腔和光学Tamm态耦合的全光二极管

为了实现全光二极管的功能设计,采用1维光子晶体非线性微腔,在1维光子晶体两端设置不同厚度的金属薄膜,并运用非线性传输矩阵方法研究了该结构的传输属性。结果表明,两个非对称光学Tamm态和非线性微腔的耦合结构呈现双稳态,且滞回线的位置与入射方向有关,具有全光二极管功能;光二极管的性能依赖于微腔厚度和两个金属薄膜的厚度比。该设计为全光二极管的性能优化提供了参考。     

二维光子晶体耦合腔的多模双稳态光开关

利用时域有限差分数值模拟方法和耦合模理论分析方法,研究了Kerr型非线性二维光子晶体耦合腔结构中的光学双稳态开关。利用耦合模理论,分析了耦合腔结构的多模特性,以及对应本征态的局域强度分布特性,并讨论了在耦合腔结构中实现多模光学双稳态开关的原理。发现在二维耦合腔结构中,可以实现信号自泵浦和泵浦-信号两种类型的双稳态开关,且后者具有使泵浦和信号在频率和空间相分离的优点。利用非线性时域有限差分数值模拟方法,得到了高斯脉冲激励下的双稳态响应曲线。     

Measurements and modeling of reflective bistability in 1.55-μmlaser diode amplifiers

We present experimental measurements of bistable characteristics for the case of a 1.55-μm symmetric Fabry-Perot laser amplifier with a particularly rich variety of behavior for reflected signals. Three main forms of hysteresis loops are observed on reflection. The hysteresis loop changes from anticlockwise to clockwise hysteresis in the optical output-input characteristic when the drive current or initial phase detuning is changed. A “butterfly” hysteresis loop is observed experimentally at an optical input power as low as 300 μW for a drive current equal to 94% of the lasing threshold. The dependence of the reflective optical bistability on drive current, initial phase detuning, and injected optical pewter has been investigated for the first time in an uncoated 1.55-μm amplifier. Measurements of the device voltage shifts on switching reveal hysteresis loops which match those in the corresponding optical powers and which indicate the amount of gain saturation and nonlinear refraction responsible for bistability. An analytical model is used to describe the observed reflective bistability and to give insight into the detailed physical mechanisms responsible     

Closed form theory of multicavity reflectors and the output power of external cavity diode lasers

A closed form solution for the transmission and reflection coefficients of a double cavity Fabry-Perot resonator is given. The explicit expressions for these coefficients are used in a formula to give the output power of diode lasers coupled to multiple external cavities. Analysis of a cleaved or etched coupled-cavity laser shows that stable operation depends on proper choice of the phase length of both the gap and the control section. A study of a diode laser coupled to an external waveguide containing a Bragg reflector shows that for correct choice of grating reflectivity only modestly effective antireflection coatings (5 percent on laser facet and 2 percent on waveguide face) are required to allow the grating to dominate the operating wavelength of the laser diode. A single external cavity with loss coupled to a laser diode is also considered. In this case the theory indicates the necessity of proper control of loss or coupling fraction between diode and cavity for there to be effective control of wavelength.     

Nonlinear dynamics of a laser diode with optical feedback systemssubject to modulation

The nonlinear dynamic behavior of a direct frequency-modulated diode laser with strong optical feedback is examined and compared to a laser diode subject to electro-optically modulated, strong optical feedback. Direct modulation is achieved by sinusoidal modulation of the diode laser injection current. Electro-optic modulation is achieved by applying a sinusoidal voltage to an intracavity phase modulating element. The output state (characterized by the output power versus time, the intensity noise spectrum and the optical frequency spectrum) for both types of modulation is dependent on the ratio of the modulation frequency to the external cavity resonant frequency, and the modulation power. A number of distinct states are observed: conventional amplitude modulation (with FM spectra); multimode, low-noise amplitude modulation; multimode, high-noise amplitude modulation; periodic limit-cycle operation; quasi-periodicity; chaos; low-frequency fluctuations; and mode-locking. There are significant differences between the direct and electro-optic frequency-modulation cases. The onset of the dynamic instability is characterized as a noisy period-one oscillation for direct modulation and a low-frequency fluctuation for intracavity electro-optic modulation. Phase portraits produced experimentally with the use of a digital phosphor oscilloscope are shown to agree well with those constructed from output power versus time data. This represents an experimental method for examining the dynamics phase portraits in real-time     

Dynamic behavior of reflection optical bistability in a nonlinearfiber ring resonator

We present an analysis of the dynamic behavior of a nonlinear fiber ring resonator when an optical pulse with an arbitrary shape envelope is incident into it through a fiber directional coupler. The transient analysis is based on the extension of a well-known multiple-beam interference method to non-linear transmission problems. The steady-state analyses reported so far predict that the ring resonator exhibits reflection optical bistability in the input-output characteristics under appropriate conditions. But, our transient analysis shows that a nearly periodical oscillation of the transmitted power always takes place at a suitable initial detuning when the resonator has no loss or a small loss. It seems that the present instability is caused by the repetition of accumulation and release of the power in the ring resonator. We can obtain a bistable hysteresis loop by introducing a loss to the directional coupler. The dynamic behavior of bistability in a nonlinear fiber ring resonator with coupler loss is then investigated. It is found that a remarkable undershoot and overshoot occur in the switch-off curve and switch-on curve, respectively     

光纤耦合光双稳半导体激光器的研究

介绍一种紧凑的、能以较低输入光功率工作的光学双稳器件,由光电检测器、光纤定向耦合器和半导体激光二极管组合而成的。描述了工作原理,解释所观测到的一些效应,例如滞后回线、微分增益以及记忆功能。     

端面抽运全固态皮秒被动锁模激光器

利用国产半导体可饱和吸收镜(SESAM),设计了不同的腔型结构,实现了平均功率5W单路输出,5W双路输出,输出透过率可调节的半导体可饱和吸收镜线型腔连续锁模(CWML)激光器,双向输出六镜环行腔连续锁模激光器等。将半导体可饱和吸收镜放在腔内的特殊位置,利用一种新的技术方法实现了锁模激光器的频率翻倍。利用由非线性晶体KTP和双色镜构成的非线性镜(NLM),实现了端面抽运Nd∶YVO4激光器的4W锁模输出。     

Single-axial mode, intracavity doubled Nd:YAG laser

A diode-pumped, single-axial mode, intracavity doubled laser has been demonstrated using a cavity consisting of only two intracavity components, a Brewster angle cut piece of Nd:YAG and a KTP doubling crystal. Up to 4 mW single-ended output power has been obtained for 260 mW incident power on the Nd:YAG. Threshold power was 31 mW of diode power incident on the YAG; thus, single-mode operation was attained at up to ~8.5 times threshold. At the highest power the laser was susceptible to multimode operation due to spatial hole burning effects but below ~5 times threshold reliable single mode operation was achievable     

Optical tristable device by vertical and direct integration ofheterojunction phototransistors and laser diodes

A light-controlled optical tristable device with an optical gain is actualized. The device has a configuration of vertical and direct integration of two heterojunction phototransistors (HPTs) on a laser diode (LD) along the cavity direction. An external optical input causes a bistable operation in one HPT+LD part. With the optical connection between two HPTs through the LD stripe, a bistable operation also occurs in the other HPT+LD part. The light-controlled optical tristability is achieved with the combination of the bistable operation in each HPT+LD part     

非线性法布里-珀罗腔的双稳态特性分析

应用传输矩阵的方法研究了垂直微腔多量子阱结构的双稳态特性,计算结果表明,分布布喇格反射器（ＤＢＲ）的高折射率介质紧挨着非线性介质（多量子阱结构）时更容易产生双稳态,我们计算了非线性法布里－珀罗腔的反射相位与入射光功率关系曲线,反射率与入射光功率的关系曲线,和作为反射镜的ＤＢＲ的对数对双稳态性质的影响等。     

Intensity independent bistable polarization switch based on orderedGaInP

We present a polarization sensitive device showing an adjustable bistable switching behavior. It exhibits switching contrasts of up to 30 dB, electrooptical gains of 40 dB, and an angle hysteresis which can be tuned between 0° and 60°. Furthermore, the polarization characteristics are independent of the incident optical power     

LD泵浦单频Nd:YVO4绿光激光器

采用复合腔与布氏片相结合的方式实现单纵模的有效选取,LD采用紧贴式端面泵浦,通过精密调控Nd:YVO4、KTP及泵浦源LD的温度以达到有关参数的最佳匹配,从而实现了稳定的单频绿光输出.在抽运功率为500mW时,获得38mW的单频连续稳定运转的532nm的绿光输出,其光-光转换效率为7.6%.     

半导体激光器的光学可双稳静态工作特性的分析

本文给出了半导体激光器光学可双稳静态特性的分析。使用电子和光子密度的非线性速率方程,得到了光学可双稳半导体激光二极管(BILD)光输出的一种简单模型。该模型强调物理机制以及和双稳性有关的参数给出了态方程,并解释了BILD的主要特征。在P_oP_i特性中具有很大滞后回线的双稳性是BILD的突出特点。     

基于一维非线性光子晶体的光学二极管的优化设计

基于F-P腔理论研究了不对称非线性缺陷光子晶体的光学二极管效应。要有效提高光学二极管的正反向透射比，同时又要保证正向透射率不太低，应增大入射光频率的预置量，适当提高缺陷两侧结构的不对称性，并使入射光强在相应变化范围内靠近低值。数值模拟结果支持了该理论的分析。