High Quality Pseudomorphic In0.24 GaAs/GaAs Multi-Quantum-Well and Large-Area Transmission Electro-Absorption Modulators

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2013,（4）
• 页码范围: 133-135
• 页数: 3页
• 语种: 英文
• DOI: 10.1088/0256-307X/30/4/046102

摘要

Large-area optical modulators have been explored recently for free-space communication.[1,2] A kind of asymmetric optical links is popular because compared with radio-frequency links,the optical terminals are smaller in size and the optical links are difficult to intercept.In such communication links,a modulator is used in conjunction with an optical retro-reflecting system,so that a remote laser directed at the system passes through the modulator,being imprinted with a data signal,and returns to the remote station,allowing readout of the data.[3] Some laboratories have worked on the development of modulator retroreflecting (MRR) systems based on multiple-quantumwell (MQW) modulators.[1,3] This kind of transmission modulator is easier to grow and fabricate than the resonant-cavity enhanced modulator.[4] Since reverse biases of tens of volts are typically required to drive the MQW modulator devices,a leakage of even 1 mA results in power dissipation in tens of milliwatt.InP-based 1.06 μm and 1.55 μm devices suffer lowered yield,due to the large leakage current under reverse bias.It will be a great problem since these devices are intended to operate in power limited situations.The dark current of GaAs-based modulators is quite low,but the working wavelength is limited to be less than 950 nm without InGaAs bnffer layers.[5,6]They will act as a more important role if the longer wavelength can be reached.