Laser Intensity Noise Suppression for Preparing Audio-Frequency Squeezed Vacuum State of Light
- Resource Type
- article
- Authors
- Lele Bai; Xin Wen; Yulin Yang; Jun He; Junmin Wang
- Source
- Applied Sciences, Vol 10, Iss 4, p 1415 (2020)
- Subject
- laser intensity noise
feedback loop
squeezed vacuum state of light
acousto-optical modulator (aom)
audio frequency
Technology
Engineering (General). Civil engineering (General)
TA1-2040
Biology (General)
QH301-705.5
Physics
QC1-999
Chemistry
QD1-999
- Language
- English
- ISSN
- 2076-3417
Laser intensity noise suppression has essential effects on preparation and characterization of the audio-frequency squeezed vacuum state of light based on a sub-threshold optical parametric oscillator (OPO). We have implemented two feedback loops by using relevant acousto-optical modulators (AOM) to stabilize the intensity of 795-nm near infrared (NIR) fundamental laser and 397.5-nm ultraviolet (UV) laser generated by cavity-enhanced frequency doubling. Typical peak-to-peak laser intensity fluctuation with a bandwidth of ~10 kHz in a half hour has been improved from ±7.45% to ±0.06% for 795-nm NIR laser beam, and from ±9.04% to ±0.05% for 397.5-nm UV laser beam, respectively. The squeezing level of the squeezed vacuum state at 795 nm prepared by the sub-threshold OPO with a PPKTP crystal has been improved from −3.3 to −4.0 dB around 3~9 kHz of analysis frequency range.