Study On Temperature Control Technology Of Semiconductor Lasers And Integrated Devices

Semiconductor lasers are key devices in optical fiber communication. With increasing capacity in internet transmission, systems composed of discrete devices, such as semiconductor lasers, et al. are becoming complicated, large in size, high in cost and power consumption. Photonic Integrated Circuits(PICs) are widely introduced in contemporary optical communication technologies. PICs can effectively reduce the size, coupling loss between elements, cost in packaging, and obtain low power consumption.Many characteristics of semiconductor materials are related with temperature. This is why optical devices, especially PICs are so thermo-sensitive. In PICs, there exists not only thermal crosstalk between different elements, but also a thermal stability time when the operation state changes. The high density of PICs also makes the TEC power consumption getting higher. Therefore, studies on thermal properties of the semiconductor laser and related integration devices are very important. The main contents of this paper are organized as follows:(1) Element models of the semiconductor laser and its integrated devices are developed based on finite element method, including TEC, DFB(Distributed Feed Back) laser, EAM(Electro-absorption Modulator), SOA(Semiconductor Optical Amplifier), SG-DBR(Sample Grating Distributed Bragg Reflector) laser. These models are simplified with good accuracy, which increases the simulation efficiency a lot.(2) Thermal time constant is used to roughly evaluate the thermal switch time in the semiconductor laser and its integrated devices. A new method to get PID(ProportionalIntegral-Differential) coefficient with thermal time constant is proposed. Besides, we suggested some ways to reduce thermal time constant by changing the material and geometrical parameter of submount or thermistor. The thermal switch time in PICs is demonstrated with an analysis of an amplifier integrated SG-DBR laser.(3) The TEC power consumptions in DFB laser and modulator- and amplifierintegrated DFB laser array are analyzed and compared. Approaches of using different materials for submount and using different stage TECs are proposed to reduce the power consumption. The protocol standards of the optical module formulate the device size, which limit the dimensions of TEC. By comparing the performance of TECs with different dimensions, we suggested the ways and advices in TEC selection.