双偏振双波长混合应变量子阱激光器

本文报道了以混合应变量子阱结构为有源区的激光器。对有源区分别采用体材料、匹配量子阱、压应变量子阱和混合应变量子阱结构的激光器进行了比较。混合应变量子阱激光器能同时工作于两种偏振模式，而且两种偏振模式的激射波长不同。结合实验结果，我们可以看出在混合应变量子阱结构中，从偏偏自发辐射谱峰值长差不能推断两种量子陆的能带填充效应大小。     

低偏振灵敏度半导体光放大器

报道了基于混合应变量子阱材料的半导体光放大器 (SOA)。利用张应变量子阱加强了TM模的增益 ,使之接近TE模的增益 ,从而使SOA的偏振灵敏度大为降低。在 150mA的偏置下 ,获得了 2 4dB的小信号增益和 1dB的偏振灵敏度。     

1.55μm波段低偏振灵敏度半导体光放大器

研制了１．５５μｍ波段低偏振灵敏度的半导体光放大器（ＳＯＡ）．其有源区材料采用张应变和压应变交替排列的混合应变量子阱结构,由ＭＯＣＶＤ生长．张应变量子阱加强了ＴＭ模式的增益,改善了ＳＯＡ的偏振灵敏度．腔长为４００μｍ的单端耦合ＳＯＡ,在１６０ｍＡ偏置下,增益大于１６ｄＢ,偏振灵敏度约为１．８ｄＢ．     

1.3μm高增益偏振无关应变量子阱半导体光放大器

采用低压金属有机化学气相外延法 (LP MOVPE)生长并制作了 1 3μm脊型波导结构偏振无关半导体光放大器 (SOA) ,有源区为基于四个压应变量子阱和三个张应变量子阱交替生长的混合应变量子阱 (4C3T)结构 ,压应变阱宽为 6nm ,应变量 1 0 % ,张应变阱宽为 11nm ,应变量 - 0 95 % ;器件制作成 7°斜腔结构以有效抑制腔面反射。半导体光放大器腔面蒸镀Ti3 O5/Al2 O3 减反 (AR)膜以进一步降低腔面剩余反射率至 3× 10 -4以下 ;在 2 0 0mA驱动电流下 ,光放大器放大的自发辐射 (ASE)谱的 3dB带宽大于 5 0nm ,光谱波动小于 0 4dB ,半导体光放大器管芯的小信号增益近 30dB ,在 12 80～ 1340nm波长范围内偏振灵敏度小于 0 6dB ,饱和输出功率大于 10dBm ,噪声指数 (NF)为 7 5dB。     

AlGaInAs-InP材料系1550nm偏振无关半导体光放大器

采用低压金属有机气相外延设备生长并制作了1550nm AlGaInAs-InP偏振无关半导体光放大器,有源区为3周期的张应变量子阱结构,应变量为-0.40%.器件制作成脊型波导结构,并采用7°斜腔结构以有效抑制腔面反射.经蒸镀减反膜后,半导体光放大器的自发辐射功率的波动小于0.3dB,3dB带宽为56nm.半导体光放大器小信号增益近20dB,带宽大于55nm.在1500～1590nm波长范围内偏振灵敏度小于0.8dB,峰值增益波长的饱和输出功率达7.2dBm.     

1.55μm张应变InGaAsP/InGaAsP量子阱偏振不灵敏半导体光放大器的优化设计

优化设计了1.55μm InGaAsP/InGaAsP张应变量子阱偏振不灵敏半导体光放大器的结构.利用k*p方法计算了多量子阱的价带结构,计算中考虑了6×6有效质量哈密顿量.从阱宽、应变、注入载流子密度等方面计算了量子阱模式增益的偏振相关性.     

一种大功率低偏振度量子阱超辐射发光二极管

设计了一种张应变与压应变相结合的混合应变量子阱结构超辐射发光二极管,研究了TE模和TM模在器件中的模式增益,分析了影响增益偏振性的因素,在此基础上通过改变有源层量子阱的应变类型、应变量以及层数来达到高增益和偏振不敏感性。最后按设计工艺流程生长了芯片,实验结果表明,所设计的SLD芯片单管输出功率在100mA驱动电流下可达3.5mW,出射光谱FWHM约为40nm,20nm波长范围内偏振度为0.3dB,具有较理想的大功率、宽光谱、低偏振度特性。     

1.55μm张应变InGaAsP/InGaAsP量子阱偏振不灵敏半导体光放大器的优化设计

优化设计了 1.5 5 μm In Ga As P/In Ga As P张应变量子阱偏振不灵敏半导体光放大器的结构 .利用 k· p方法计算了多量子阱的价带结构 ,计算中考虑了 6× 6有效质量哈密顿量 .从阱宽、应变、注入载流子密度等方面计算了量子阱模式增益的偏振相关性 .     

AlGaInAs-InP材料系1550nm偏振无关半导体光放大器

采用低压金属有机气相外延设备生长并制作了 1 5 5 0 nm Al Ga In As- In P偏振无关半导体光放大器 ,有源区为 3周期的张应变量子阱结构 ,应变量为 - 0 .4 0 % .器件制作成脊型波导结构 ,并采用 7°斜腔结构以有效抑制腔面反射 .经蒸镀减反膜后 ,半导体光放大器的自发辐射功率的波动小于 0 .3d B,3d B带宽为 5 6 nm.半导体光放大器小信号增益近 2 0 d B,带宽大于 5 5 nm.在 1 5 0 0～ 1 5 90 nm波长范围内偏振灵敏度小于 0 .8d B,峰值增益波长的饱和输出功率达7.2 d Bm.     

AlGaInAs-InP材料系 1550nm偏振无关半导体光放大器(英文)

采用低压金属有机气相外延设备生长并制作了 1 5 5 0 nm Al Ga In As- In P偏振无关半导体光放大器 ,有源区为 3周期的张应变量子阱结构 ,应变量为 - 0 .4 0 % .器件制作成脊型波导结构 ,并采用 7°斜腔结构以有效抑制腔面反射 .经蒸镀减反膜后 ,半导体光放大器的自发辐射功率的波动小于 0 .3d B,3d B带宽为 5 6 nm.半导体光放大器小信号增益近 2 0 d B,带宽大于 5 5 nm.在 1 5 0 0～ 1 5 90 nm波长范围内偏振灵敏度小于 0 .8d B,峰值增益波长的饱和输出功率达7.2 d Bm.     

高增益偏振不灵敏InGaAs/InP体材料半导体光放大器

采用三元InGaAs体材料为有源区，通过直接在InGaAs体材料中引入0．20％张应变来加强TM模的增益，研制了一种适合于作波长变换器的偏振不灵敏半导体光放大器(SOA)。在低压金属有机化学气相外延(LPMOVPE)的过程中，只需调节三甲基Ga的源流量便可获得所要求的张应变量。制作的半导体光放大器在200mA的注入电流下，获得了50nm宽的3dB光带宽和小于0．5dB的增益抖动；重要的是，半导体光放大器能在较大的电流和波长范围里实现小于1．1dB的偏振灵敏度。对于1．55gm波长的信号光，在200mA的偏置下，其偏振灵敏度小于1dB，同时获得了大于14dB光纤到光纤的增益，3dBm的饱和输出功率和大于30dB的芯片增益。用作波长变换器，可获得较高的波长变换效率。进一步提高半导体光放大器与光纤的耦合效率，可得到性能更佳的半导体光放大器。     

Influence of buried structure on polarization sensitivity instrained bulk semiconductor optical amplifiers

In order to achieve an accurate design of polarization-insensitive semiconductor optical amplifiers based on tensile strained bulk InGaAsP, the reduction of strain in the active layer of the buried heterostructure and its influence on polarization sensitivity are analyzed numerically for the first time. The gain calculation, including the strain distribution in the active layer, is examined based on the k · p method for the different active layers. It is found that the strain introduced during the epitaxial growth is strongly reduced after regrowth of the burying layer. In an active layer having the aspect ratio of 1 : 4, the strain reduction causes more than a 0.5-dB deviation in the polarization sensitivity of the gain. From a comparison with the experimental results, it is shown that including the effect of the burying layer in the calculation gives an accurate determination of the amount of strain for the polarization independence     

Pure strain effect on differential gain of strained InGaAsP/InPquantum-well lasers

The effect of pure strain on the differential gain of strained InGaAsP/InP quantum-well lasers (QWLs) is analyzed on the basis of the valence band structures calculated by k×p theory. By using an InGaAsP quaternary compound as an active layer, it becomes possible to study the relationship between the differential gain and strain (both tensile and compressive) when both the quantum-well thickness and the emission wavelength are kept constant. It is shown that the tensile strain not only reduces the density of states in the valence band but also increases the energy spacings between the first two valence subbands. It is concluded that tensile strain has a more pronounced impact on the improvement of differential gain in InP-based, strained QWLs as compared with compressive strain     

High-Confinement Strained MQW for Highly Polarized High-Power Broadband Light Source

This letter presents highly polarized edge light-emitting diodes with high-confinement, strained, multiple quantum-well active regions. We demonstrate +40 dB of polarization extinction along with 16 dBm of output power from an 800-mum-long centered quantum-well device. By characterizing the polarization extinction and gain of devices with different lengths and optical confinement, we show that the polarization extinction is dominated by the polarization sensitivity of the gain     

Theory of Optical Gain of Ge-SixGeySn1−x−y Quantum-Well Lasers

We develop a theoretical model for optical gain of a strained Ge--Si_xGe_ySn_1-x-y quantum-well (QW) structure. By using a ternary Si_xGe_ySn_1-x-y material system as the barriers, a tensile strained germanium QW with a direct band gap for the electron and hole confinements can be realized. We show our theoretical model for the strained band structure and the polarization dependent optical gain spectrum of the tensile strained germanium QW laser taking into account the carrier occupations in both the Gamma- and L-valleys of the conduction band. Reasonable material parameters are used to estimate the transition energy, optical gain spectrum, and effects of the carrier leakage in presence of the quantized subbands     

1.5 μm multiquantum-well semiconductor optical amplifier withtensile and compressively strained wells for polarization-independentgain

A multiquantum-well optical amplifier for 1.5-μm wavelength operation using alternating tensile and compressively strained wells in the active region is described. For each bias level measured, the polarization sensitivity of the amplifier gain is 1 dB or less averaged over the gain bandwidth. This amplifier is suitable for integration with other optical devices in photonic integrated circuits which require polarization-independent gain     

Fabrication and characterization of 1 550 nm polarization-insensitive semiconductor optical amplifiers

Semiconductor Optical Amplifiers (SOAs) can beused asin-line amplifier ,preamplifier ,optical switch,andwavelength converter in future optical systems[1-3].Po-larization-independent gain,high output power and lowgain ripple are desirable features for most…     

大带宽半导体光学放大器的理论分析

提出一种新型的半导体光学放大器结构,并从增益谱和能带结构等角度分析其特征,得出其大带宽内偏振不灵敏的原因和规律.通过剖析该结构中有源区各部分的作用,得出大的张应变的引入主要是用于提高TM模的材料增益,获得偏振不灵敏和大的TE模带宽,减小制备难度.厚的无应变层的引入主要是为了改善有源层晶体质量,获得大的偏振不灵敏模式增益.     

Analysis of the performance of 1.55-μm InGaAs-InP tensilestrained quantum-well lasers

We fabricated 1.55-μm tensile strained InGaAs quantum-well (QW) lasers into broad-area and ridge waveguide lasers, and their performance was analyzed and compared with compressive strained and lattice-matched QW lasers. It is seen that the limitation on the tensile strain to a value less than 0.7%, which is required to prevent the emission wavelength being shorter than 1.55 μm, imposes restrictions on the performance enhancement in several aspects. Broad-area InGaAs QW lasers with a tensile strain of 0.7% show a larger gain coefficient and smaller transparency current density per well than those with InGaAsP QW lasers with a compressive strain of 1.0%. However, the internal quantum efficiency is much smaller than that for compressive ones and the internal optical loss increases rapidly as the number of QW's increases. These are thought to be caused by a smaller conduction band offset and the onset of dislocation generation at the well-barrier interfaces with the number of QW's, respectively. Ridge waveguide lasers with two QW's with tensile strain of 0.7%, which is designed not to exceed the critical thickness for dislocation generation, show smaller modal gain coefficients and inferior temperature characteristics as compared to those with six 0.7% compressive strained QW's and those with three lattice matched InGaAs QW's. However, the modulation bandwidth is measured to be larger than that for one that is compressively strained. It is believed to originate from the small effective capture time of the carriers due to thicker wells