A 23.75-GHz frequency comb with two low-finesse filtering cavities in series for high resolution spectroscopy

• 作者: 侯磊 庞利辉 张龙 李德华 王薇 韩海年 魏志义
• 来源期刊: 中国物理B（英文版）
• 关键词: laser frequency comb Fabry-P ′erot cavity high repetition rate high resolution spectroscopy
• 年，卷（期）: 2015,（2）
• 页码范围: 024213-1-024213-5
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/24/2/024213

摘要

A laser frequency comb with several tens GHz level is demonstrated, based on an Yb-doped femtosecond fiber laser and two low-finesse Fabry–P′erot cavities (FPCs) in series. The original 250-MHz mode-line-spacing of the source comb is filtered to 4.75 GHz and 23.75 GHz, respectively. According to the multi-beam interferences theory of FPC, the side-mode suppression rate of FPC schemes is in good agreement with our own theoretical results from 27 dB of a single FPC to 43 dB of paired FPCs. To maintain long-term stable operation and determine the absolute frequency mode number in the 23.75-GHz comb, the Pound–Drever–Hall (PDH) locking technology is utilized. Such stable tens GHz frequency combs have important applications in calibrating astronomical spectrographs with high resolution.