光学学报, 2016, 36 (6): 0614001, 网络出版: 2016-06-06
2.16 m望远镜高分辨率光谱仪的天文光学频率梳
Astronomical Laser Frequency Comb for High Resolution Spectrograph of a 2.16-m Telescope
激光器 光纤激光器 天文光谱仪 视向速度 超连续光谱 lasers fiber lasers astronomical spectrograph radial velocity supercontinuum
摘要
介绍了应用于我国兴隆观测站2.16 m望远镜高分辨率光谱仪的天文光学频率梳。采用掺镱光纤激光频率梳作为源光梳,通过模式滤波使模式间隔达到25 GHz,与天文光谱仪的分辨率相匹配。光谱展宽和平滑后,光谱覆盖可见光范围达到270 nm以上,光谱平滑度可长期保持在1 dB范围内,边模抑制比达到42 dB。该天文光学频率梳的视向速度理论定标精度可达cm/s量级,使寻找系外类地行星乃至直接测量宇宙膨胀速度成为可能。
Abstract
An astronomical laser frequency comb (astro-comb), which will be applied as a calibrator on the high resolution spectrograph of the 2.16-m telescope in Xinglong Observatory, is introduced. The astro-comb is based on an ytterbium-doped fiber laser frequency comb. By mode filtering, the mode spacing of the comb is increased to 25 GHz, which matches the resolution of the astronomical spectrograph. After spectral broadening and flattening, the spectrum span increases to more than 270 nm in visible range, the spectrum flatness maintains within 1 dB for a long time, and the side mode suppression ratio reaches 42 dB. The theoretical calibration precision of the radial velocity for the astro-comb reaches cm/s level, which meets the requirements for searching the earth-like extrasolar planets and directly detecting the acceleration of the cosmic expansion.
吴元杰, 叶慧琪, 韩建, 邹璞, 傅凌统, 肖东. 2.16 m望远镜高分辨率光谱仪的天文光学频率梳[J]. 光学学报, 2016, 36(6): 0614001. Wu Yuanjie, Ye Huiqi, Han Jian, Zou Pu, Fu Lingtong, Xiao Dong. Astronomical Laser Frequency Comb for High Resolution Spectrograph of a 2.16-m Telescope[J]. Acta Optica Sinica, 2016, 36(6): 0614001.