Optical Multistability and Wavelength Switching of a Fabry-Perot Semiconductor Laser with Multi-Detuned Light Injections

Optical multistability of a Fabry-Perot semiconductor laser is analyzed when multi-optical inputs detuned from the cavity-resonant wavelength of a semiconductor laser are injected. Many split branches are shown to be produced in the optical output versus optical input characteristics for different detuned optical inputs. It is also shown that optical outputs can be switched in any one of the optical input wavelengths by optical input pulses, based on the optical output versus input characteristics with multi-split branches.     

Switching of a Semiconductor Laser with Multi-Detuned Optical Inputs by Controlling Injection Current

The multistability of a Fabry-Perot semiconductor diode laser for an injection current is presented when multi-optical inputs detuned from the cavity-resonant wavelength of a semiconductor laser are injected. m+1 Multi-stable states are shown to be produced in the optical output versus injection current characteristics for m detuned optical inputs. It is shown that optical output can be switched in any one of the optical input wavelengths in a relatively fast response time by applying injection current pulses. Analytical expression based on linear stability analysis is presented to predict the switching time to free oscillating mode, and larger optical input power and detuning are effective to shorten the switching time. The results here are believed to be useful to extend wavelength switching to a scope of electronic manipulation without modulation of optical inputs and can be applicable to actual devices.     

Dynamics of an Optically Switched Bistable Semiconductor Laser

The switching time of an optically switched laser diode between a locked mode and free oscillation mode is studied. By starting with linear stability analysis, analytical expressions are developed to predict the switching time. It is shown that the switching of optical output between the locked and unlocked modes is governed by two relaxation processes with different time constants, and the change in the first relaxation process, dependent on the carrier density in the initial state, gives a strong effect on the total switching time, in contrast to the dynamic behavior of the carrier density dominated by a single relaxation process. Our analytical results show that larger detuning and power of optical input are effective in shortening the switching time and are believed useful to estimate the switching time of an optically switched bistable laser diode.     

利用光栅测半导体激光波长

依据光栅衍射原理,采用玻璃圆柱把半导体激光扩束成片光源,通过分光计测量激光光谱谱线的衍射角,测定半导体激光波长.这种方法操作简单实用,具有较高的测量精度.     

输入光特性对超快非线性干涉仪开关窗口的影响

就超快非线性干涉仪(UNI)的输入光特性对其开关窗口的影响进行了数值模拟和实验研究,输入光包括控制光脉冲和探测光脉冲。在数值模拟中,调节控制光脉冲和探测光脉冲的功率及脉宽,功率越高和脉宽越窄,窗口的形状越好。在调节过程中发现控制光脉冲和探测光脉冲都存在一个最佳的功率点使窗口的形状达到最优。如果继续增大控制光脉冲功率,会使窗口的顶部倾斜,窗口形状恶化;而继续增大探测光脉冲功率,窗口的消光比开始下降。在数值模拟的基础上进行了10Gb／s的超快非线性干涉仪全光开关实验,在实验中用连续光代替探测光脉冲以观察窗口形状。通过改变控制光脉冲和连续光功率来验证它们对超快非线性干涉仪开关窗口的影响。实验表明,应选用短而强的控制光脉冲和最优功率点的连续光,这与模拟结果吻合。     

外注入非制冷式FP半导体增益开关激光器产生低抖动光脉冲的实验研究

报道了低成本、非制冷法布里-玻罗腔半导体增益开光激光器稳定地产生超短脉冲的实验研究.通过使用外部连续光注入,增益开光激光器的脉冲抖动得到了有效的抑制.实验结果表,明当选择合适功率的连续光注入到非制冷半导体增益开关激光器腔内,可以稳定地产生脉宽26 ps、抖动低于400 fs、重复频率2.5 GHz的脉冲序列.     

Dynamic Wavelength Tuning of a Fiber Ring Semiconductor Laser

ＤｙｎａｍｉｃＷａｖｅｌｅｎｇｔｈＴｕｎｉｎｇｏｆａＦｉｂｅｒＲｉｎｇＳｅｍｉｃｏｎｄｕｃｔｏｒＬａｓｅｒＬＵＯＢｉｎＬ¨ＵＨｏｎｇｃｈａｎｇＰＡＮＷｅｉＣＨＥＮＪｉａｎｇｕｏ（ＳｏｕｔｈｗｅｓｔＪｉａｏｔｏｎｇＵｎｉｖｅｒｓｉｔｙ，Ｃｈｅｎｇｄｕ６...     

半导体激光器实现波长转换的理论模型分析

作为自动交换光网络中的核心器件，全光波长转换器的研究是目前的热点。提出了基于半导体激光器实现波长转换的理论模型，采用小信号分析方法，利用速率方程求解了波长转换的频率调制响应特性。并初步研究了不同半导体激光器工作电流、码速、输入信号光功率、增益吸收系数条件对波长转换性能的影响。这对于优化基于半导体激光器的全光波长转换器有一定的参考价值。     

程控宽带连续调谐外腔半导体激光器特性分析

对宽带调谐外腔半导体激光器进行了理论及实验研究,分析了其最大调谐范围和连续调谐条件,为宽带可调谐激光器的设计提供了依据。完成了实用化的程控宽带连续调上腔激光器,该器件调谐范围超过７５ｎｍ,波长重复性精度为１ｎｍ,分辨率为０．０１ｎｍ。     

一种新颖的偏振不敏感的基于半导体光放大器的四波混频光波长转换方法

提出和论述了一种新颖的偏振不敏感的基于半导体光放大器的四波混频光波长转换方法。基本思想是设计和采用一种全光学偏振态转换器 ,理论上能将随机偏振态的输入信号光转换为固定偏振方向且功率基本不变的线偏振光 ,利用它控制信号光的偏振态能够克服四波混频过程所固有的偏振敏感性。将这种方法与正交偏振双抽运方法结合起来 ,能较简单地实现偏振不敏感且具有近似常数转换效率的宽带四波混频光波长转换     

A Novel Method for Wavelength Conversion with Dual-pump Four-wave Mixing in a Semiconductor Optical Amplifier

Using a semiconductor-fiber ring laser, a novel method for the all optical wavelength conversion based on dual-pump four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) is demonstrated. For the input signal with different wavelengths, only one external pump is needed. This scheme can simplify the dual-pump FWM in SOA and has nearly constant conversion efficiency and signal-to-noise ratio (SNR) over 50nm range of wavelength shifts.     

吸收型双稳半导体激光器的起振波长

从双稳半导体激光器上跳阈值处的谐振波长是所需阈值电流最低的波长这个物理事实出发，利用双稳半导体激光器的速率方程组，本文对双稳半导体激光器上跳阈值处的谐振波长进行了研究。文中还就一些器件参量对双稳半导体激光器上跳阈值处谐振滤长的影响进行了讨论。     

A Novel Method for Wavelength Conversion with Dual-pump Four-wave Mixing in a Semiconductor Optical Amplifier

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　ＩｎｔｈｅＷＤＭｎｅｔｗｏｒｋ ,ｔｈｅｄｅｓｉｒａｂｌｅｆｅａｔｕｒｅｓｏｆａｎａｌｌ ｏｐｔｉｃａｌｗａｖｅｌｅｎｇｔｈｃｏｎｖｅｒｔｅｒｉｎｃｌｕｄｅｐｏｌａｒｉｚａｔｉｏｎｉｎｓｅｎｓｉｔｉｖｉｔｙ ,ｔｒａｎｓｐａｒｅｎｃｅｔｏｍｏｄｕｌａｔｉｏｎｆｏｒｍａｔａｎｄｂｉｔ ｒａｔｅ ,ｆｕｌｌｔｕｎａｂｉｌｉｔｙ ,ａｃｃｅｐｔａｂｌｅｏｕｔｐｕｔＳＮＲｏｖｅｒｔｈｅｅｎｔｉｒｅｒａｎｇｅｏｆｔｈｅｗａｖｅｌｅｎｇｔｈｓｕｓｅｄｉｎｔｈｅｎｅｔｗｏｒｋ[1] .Ｗａｖｅ…     

Dynamics of Optical Switching and Stability Analysis of a Polarization Bistable Laser Diode with Detuned External Light Injection

Dynamic behaviors of a polarization-bistable laser diode with detuned light injection are studied, including slow, fast and overshoot switching processes. Dependences of switching time of optical outputs between locked and free oscillating modes on the detuning and power of optical input, carrier injection rate and cross-gain saturation coefficients are investigated. Based on linear stability analysis the system stability is analyzed and analytical expressions are developed to predict the switching time. Our analytical results, in which the switching of optical output from locked to unlocked modes is shown to be composed of two relaxation processes with short and long time constants, are in agreement with the numerical results showing fast and slow switching behaviors dependent on the initial locked state, in contrast to the dynamic behavior of the carrier density dominated by a single relaxation process.     

In-Phase Wavelength Conversion Based On Cross-Gain Modulation in Semiconductor Optical Amplifier

In-phase wavelength conversion based on cross-gain modulation in a semiconductor optical amplifier biased around critical threshold current has been demonstrated. The converted signal and the pump signal have the same bit sequence 1101011000. The stimulated emission competition between the amplification of input signals and the amplified spontaneous emission was used to illustrate the conversion mechanism. Experiment results showed that in-phase wavelength conversion can be achieved with simple structure and high output extinction ratio.     

基于半导体光放大器四波混频效应的多种调制格式的波长转换实验

实验报道了利用半导体光放大器(SOA)的四波混频(FWM)效应实现多种码型的波长转换.其中对于非归零(NRZ)信号实现了从单信道到三信道的多波长转换.调制速率从10 Gb/s到40 Gb/s均实现多波长转换.对于归零(RZ)信号分别实现了20 Gb/s和40 Gb/s的RZ格式的波长转换和40 Gb/s的载波抑制归零(CSRZ)格式的波长转换,利用光纤布拉格光栅(FBG)作为带陷滤波器消除共轭光和抽运光之间的串扰.对于非归零差分相移键控(NRZ_DPSK)信号分别实现了20 Gb/s和40 Gb/s的波长转换,利用实验室自制的光纤延时干涉仪进行NRZ-DPSK信号的解调.基于FWM效应的转换光的输出消光比大于7 dB,转换后消光比退化约为3 dB.     

In-Phase Wavelength Conversion Based On Cross-Gain Modulation in Semiconductor Optical Amplifier

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｃｒｏｓｓ ｇａｉｎｍｏｄｕｌａｔｉｏｎ (ＸＧＭ )ｉｎｓｅｍｉｃｏｎｄｕｃｔｏｒｏｐｔｉｃａｌａｍｐｌｉｆｉｅｒｓ (ＳＯＡｓ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｅｆｆｉｃｉｅｎｔｗａｙｓｔｏａｃｈｉｅｖｅａｌｌ ｏｐｔｉｃａｌｗａｖｅｌｅｎｇｔｈｃｏｎｖｅｒｓｉｏｎａｎｄｈａｓｓｉｍｐｌｅｉｍｐｌｅｍｅｎｔａｔｉｏｎ ,ｌａｒｇｅｗａｖｅｌｅｎｇｔｈｃｏｎｖｅｒｓｉｏｎｓｐａｎ ,ｈｉｇｈｃｏｎｖｅｒｓｉｏｎｅｆｆｉｃｉｅｎｃｙ[1] ａｎｄｅｘｔｒｅｍｅｌｙｈｉｇｈｂｉｔｒａｔｅ…     

The Study on the Performance of the Wavelength Conversion Based on a Tunable External Cavity Semiconductor Laser

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ａｌｌｏｐｔｉｃａｌｗａｖｅｌｅｎｇｔｈｃｏｎｖｅｒｔｅｒｓ,ｔｈａｔｔｒａｎｓｆｏｒｍｉｎｆｏｒｍａｔｉｏｎｏｎｏｎｅｗａｖｅｌｅｎｇｔｈｔｏａｎｏｔｈｅｒ,ｗｉｌｌｂｅｉｍｐｏｒｔａｎｔｉｎｆｕｔｕｒｅｏｐｔｉｃａｌｓｗｉｔｃｈｅｓａｎｄｗａｖｅｌｅｎｇｔｈｍｕｌｔｉｐｌｅｘｅｄｎｅｔｗｏｒｋｓ.Ｔｈｅｒｅａｒｅｔｈｒｅｅｋｉｎｄｓｏｆｗａｖｅｌｅｎｇｔｈｃｏｎｖｅｒｔｅｒｓ:ｗａｖｅ ｍｉｘｉｎｇ ,ｏｐｔｉｃａｌｇａｔｉｎｇａｎｄｌａｓｅｒｃｏｎｖｅｒｔｅｒ[1～ 3…     

强反馈光纤光栅外腔半导体激光器

在理论上对强外腔反馈情形的半导体激光器线宽压窄效应进行了分析，对消反膜剩余反射率，外腔反射率，外腔腔长对线宽压缩的影响进行了研究，在实验上采用光纤光栅作为反馈元件，与一端镀有消反膜的１．５μｍ波段的常规多纵模交导体激光器耦合，构成强反馈光纤光栅外腔半导体激光器，得到单频窄线宽的激光输出，静态下边模抑制比大于３０ｄＢ，线宽小于１２０ｋＨｚ。     

基于半导体光放大器和整形滤波器的40 Gb/s的归零正码波长变换研究

理论上分析了通过整形滤波器方法实现正码波长变换的原理,并讨论了滤波器带宽及偏移方向对正码脉冲效果的影响,解释了目前实验报道中多采用蓝移滤波方案的技术根由。在实验上利用半导体光放大器(SOA)和通带滤波器完成了40Gb/s的归零码波长变换实验,验证了理论分析的结构,证明了整形滤波器加半导体光放大器的方案可以实现正码的波长变换。这对于简化网络的设计,提高信号传输质量都有重要的意义。