通过λ/2波片外腔同位相弱反馈实现激光二极管激光的强度噪声压缩

INTENSITY NOISE SQUEEZING OF LASER DIODE WITH INPHASE EXTERNAL WEAK FEEDBACK BY HALF WAVE PLATE

由于低温下单模半导体量子阱激光器与准直透镜出现双折射效应 ,导致输出光场偏振状态发生变化 ,使单个线偏模的光子数噪声增加 .利用λ/4波片补偿双折射 ,同时采用λ/2波片前后表面的同位相余反射光完成对激光二极管激光器的弱反馈 ,在抽运电流为 34.6 5mA时 ,获得压缩度为 2 .8dB ,输出功率约 2

Due to the birefringence effect of the quantum well laser and the collimating lens in a low temperature cryostat, the polarization of the output light was changed, therefore the photon number fluctuation of the output individual linearly polarized mode was increased. By compensating the birefringence with a quarter wave plate, and utilizing an inphase external weak feedback to laser diode laser by means of residuary reflection from the two surfaces of a half wave plate, we obtained the output light of 24mW. with the photon number fluctuation 2.8dB below the Standard Quantum Limit at the pump current of 34.65mA.