多通道PPLN波导温度控制方法

Temperature Control Method for Multichannel PPLN Waveguides

转换效率是周期性极化铌酸锂(PPLN)波导的主要性能指标,其与温度具有很强的关联性。受限于工艺问题,波导各个通道之间的一致性很难保证。提出一种多通道波导的温度自动控制方法,该方法通过FPGA芯片获取与多通道波导对应的多个单光子探测器探测到的光子数,并通过相应均衡算法来处理各个通道的光子数,从而确定多通道波导的最佳温度工作点,达到自动调节波导温度的目的。通过FPGA实现半导体制冷片(TEC)驱动控制、具有主动淬灭和快速恢复功能的单光子探测器,并通过均衡算法实现多通道波导温度的自动控制,实现探测效率更均匀的多通道上转换单光子阵列探测器,极大地减少前期人力投入,避免人为因素导致的误差。

Conversion efficiency is the primary performance metric of a periodically poled lithium niobate(PPLN)waveguide and strongly correlates with temperature.Multichannel waveguides are limited by process issues;accordingly,ensuring consistency between each waveguide channel is difficult.This paper proposes an automatic temperature control method for multichannel waveguides.In this method,number of photons detected using multiple single photon detectors corresponding to the multichannel waveguide is obtained by field-programmable gate array(FPGA)chips.Thereafter,the photon number data of each channel is processed using equalization algorithms to determine the optimal temperature working point of the multichannel waveguide and achieve automatic adjustment of the waveguide temperature.FPGA chips are used in this study to achieve TEC driving control,construct a single photon detector with active quenching and fast recovery functions,and achieve automatic control of multichannel waveguide temperature using an equalization algorithm.Additionally,we develop a multichannel up-conversion single photon array detector with more uniform detection efficiency,greatly reducing initial manpower investment and avoiding errors caused by human factors.