2025/05/27 by Zhongwang Pang, Pang, Zhongwang, Chunyi Li +13
Computer Science · Engineering · #FOS: Physical sciences #Geophysics and Sensor Technology #Instrumentation and Detectors (physics.ins-det) #Laser Design and Applications #Optics (physics.optics) #Sensor Technology and Measurement Systems
paper · pdf · doi:10.48550/arxiv.2505.20986
openalex publication_date 2025/05/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
With the continuous advancement of laser technology, accurately evaluating the noise spectrum of high-performance lasers has become increasingly challenging. In this work, we demonstrate a high-precision laser spectrum analyzer based on the proposed digital decoherence method, which can precisely measure the frequency noise spectrum of sub-Hz linewidth lasers. In addition, it has broad wavelength compatibility, which enables convenient switching between lasers with different center wavelengths. Its performance is validated through measurements of ultra-stable lasers. Based on the measured frequency noise power spectral density, a beta-line linewidth is determined to be 570 mHz at 10-second observation time, and the minimum observable linewidth is calculated to be 133 mHz. The system's noise floor is evaluated to be 210 mHz beta-line linewidth at 25-second observation time, and a minimum observable linewidth of 39 mHz.