Xiaocong Sun, Yajun Wang, Long Tian, Shaoping Shi, Yaohui Zheng*, Kunchi Peng
We demonstrate the dependence of the squeezing and antisqueezing factors on the seed beam power at different pump beam noise levels. The results indicate that a seed field injected into the optical parametric amplifier (OPA) dramatically degenerates the squeezing factor due to noise coupling between the pump and seed fields, even if both the pump and seed fields reach the shot noise limit. The squeezing and anti-squeezing factors are immune to the pump beam noise due to no noise coupling when the system operates for the generation of squeezed vacuum states. The squeezing factor degrades gradually as the pump beam intensity noise and seed beam power is increased. The influence of the two orthogonal quadrature variations is mutually independent of each other.
Optics letters, 44(7), 1789-1792(2019) PDF
Yongrui Guo, Minzhi Xu, Weina Peng, Jing Su, Huadong Lu*, Kunchi Peng
We realized a 101 W single-frequency continuous wave(CW) all-solid-state 1064 nm laser by means of mode self-reproduction in this Letter. Two identical laser crystals were placed into a resonator to relax the thermal lens of the laser crystals, and an imaging system was employed to realize cavity mode self-reproduced at the places of the laser crystals. Single-frequency operation of the resonator was realized by employing a new kind of high extinction ratio optical diode based on the terbium scandium aluminum garnet crystal to realize a stable unidirectional operation of the laser, together with introducing a large enough nonlinear loss to the resonator to effectively suppress the multi-mode oscillation and mode hopping of the laser. As a result, a 101 W single-frequency 1064 nm laser in a single-ring resonator was achieved with 42.3% optical efficiency. The measured power stability for 8 h and the beam quality were better than ±0.73% and 1.2, respectively.
Optics Letters, 43(24),6017-6020(2018) PDF
Shaoping Shi, Yajun Wang, Wenhai Yang, Yaohui Zheng*, Kunchi Peng
We report on a high-level squeezed vacuum state with maximum quantum noise reduction of 13.2 dB directly detected at the pump power of 180 mW. The pump power dependence of the squeezing factor is experimentally exhibited. When considering only loss and phase fluctuation, the fitting results have a large deviation from the measurement value near the threshold. By integrating green-light-induced infrared absorption (GLIIRA) loss, the squeezing factor can be perfectly fitted in the whole pump power range. The result indicates that GLIIRA loss should be thoroughly considered and quantified in the generation of high-level squeezed states.
Optics Letters, 43(21),5411-5414(2018) PDF