芯片级原子传感专用高温工作垂直腔面发射半导体激光光源研究

Vertical-cavity Surface-emitting Lasers (VCSELs) are optimal for atomic sensor, due to their excellent optical beam quality, narrow linewidth and high reliability. However, the request of VCSELs operating at high temperature for application of Chip-Scale Atomic Sensor causes generally the increase of power consumption and the difficulty to control wavelength and polarization, which restricts the development of chip-scale atomic sensor. In this project, we propose a novel design method to overcome these difficulties. Firstly, large mismatch between gain peak wavelength of the quantum well and cavity mode of the VCSEL structure, combined with low temperature-sensitive and high gain material of quaternary InAlGaAs quantum well , was presented to increase the effective modal gain and therefore to obtain the lowest threshold current density at high temperature. Secondly, a complex model with combined transverse waveguide mode for extreme small modal volume to realize lowest threshold current and traditional longitudinal cavity mode of VCSEL is proposed to accurately predict the lasing wavelength of VCSEL at high temperatures. Thirdly, a carrier-photon interaction model based on the temperature distribution across the device is established to understand the mechanism of polarization instability. Dielectric grating structure is used to realize the fully control of polarization direction. Finally, a systemized design based on the understanding of the mechanisms of power consumption, wavelength and polarization control will be established to accomplish the development of novel VCSELs for Rb and Cs atomic sensors. The operation temperature of the VCSELs is expected to be beyond 90˚C, and threshold current lower than 0.4mA, output power over 0.2mW, polarization ratio higher than 25dB will be realized. Chip-scale atomic clocks will be demonstrated to evaluate the performances of the VCSELs.

垂直腔面发射半导体激光器（VCSEL）具有高光束质量、窄线宽及高可靠性等优点而成为芯片级原子传感系统首选光源。但目前VCSEL在高温工作时存在的功耗控制、波长控制及偏振控制等科学问题尚未解决，制约了芯片原子传感系统的发展。本项目对铷、铯芯片原子传感用795nm、894nm波段VCSEL器件开展研究，提出针对高温工作VCSEL的量子阱增益峰—腔模大失配结构，采用增益稳定InAlGaAs四元量子阱，提高器件高温下的有效模式增益，降低器件功耗；建立基于温度分布的低模式体积横模波导模型及纵向腔模分析模型，实现波长精准控制；建立基于温度分布的载流子—光子相互作用模型，明确偏振转换机制，并采用低损耗介质光栅结构实现偏振控制；实现VCSEL器件工作温度>90℃，功耗低于2mW，阈值电流<0.4mA，出光功率>0.2mW，偏振抑制比大于25dB，并应用于芯片原子钟系统，考察研究激光器特性和原子钟特性。

垂直腔面发射半导体激光器（VCSEL）具有高光束质量、窄线宽及高可靠性等优点而成为芯片级原子传感系统首选光源。但目前VCSEL在高温工作时存在的功耗控制、波长控制及偏振控制等科学问题尚未解决，制约了芯片原子传感系统的发展。本项目对铷、铯芯片原子传感用795nm、894nm波段VCSEL器件开展研究，提出针对高温工作VCSEL的量子阱增益峰—腔模大失配结构，采用增益稳定InAlGaAs四元量子阱，提高器件高温下的有效模式增益，降低器件功耗；建立基于温度分布的低模式体积横模波导模型及纵向腔模分析模型，实现波长精准控制；建立基于温度分布的载流子—光子相互作用模型，明确偏振转换机制，并采用低损耗介质光栅结构实现偏振控制；实现VCSEL器件工作温度>90℃，功耗低于2mW，阈值电流<0.4mA，出光功率>0.2mW，偏振抑制比大于25dB，并应用于芯片原子钟系统，考察研究激光器特性和原子钟特性。