光控高温超导衰减器及光斑偏移对其光响应特性的影响

Optically controlled high temperature superconductor attenuator and the influence of laser beam offset on the optical resonding property

研制了工作于液氮温度的高温超导系统使用的新型光控高温超导微波可变衰减器。该衰减器的实质是利用钇钡铜氧(YBCO)高温超导薄膜极低的微波表面电阻和卓越的激光响应特性,达到了优良的衰减性能。主要结果包括:可独立使用的光控高温超导微波可变衰减器样品尺寸为12mm×8mm×0.5mm,与高温超导系统集成时无需外壳,体积与重量将大幅减小;高温超导衰减器的插入损耗小于0.2dB,比常规衰减器低1个数量级;高温超导衰减器的可变衰减精度小于0.01dB,比常规衰减器至少低1～2个数量级;在本实验条件下,当激光光斑中心偏移微带线中心0.3、0.5和0.7mm时,其衰减器插损将由0.08dB变为0.05、0.03和0.01dB,说明激光光斑偏移量是影响YBCO高温超导衰减器性能的重要因素。

A new optically controlled high temperature superconductor microwave variable attenuator used in high-temperature （273 K） superconductor（HTS） subsystem was proposed. The attenuator is based on that low microwave surface resistance and excellent laser response characteristics of YBCO film. The main results conclude： its size is 12 mm× 8mm× 0. 5mm,it also can be integrated into HTS system,insertion loss of this attenuator is about 0. 2 dB, which is one order lowre than conventional attenuators;Variable attenuating precision about 0. 01 dB can be achieved,which is 1-2 order lower than conventional attenuators. When the laser beam is away from the center of microstrip of 0.3 mm,0. 5 mm and 0.7 mm the insertion losses change from 0. 08 dB to 0. 05 dB,0.03 dB,and 0.01 dB. It illuminate that laser bean offsets is influent to insertion loss of HTS attenuator.