Lu Chuang, Vieira Francisco Senna, Głuszek Aleksander, Silander Isak, Soboń Grzegorz, Foltynowicz Aleksandra
Opt Express. 2021 Sep 13;29(19):30155-30167. doi: 10.1364/OE.435576.
We present a new design of a robust cavity-enhanced frequency comb-based spectrometer operating under the continuous-filtering Vernier principle. The spectrometer is based on a compact femtosecond Er-doped fiber laser, a medium finesse cavity, a diffraction grating, a custom-made moving aperture, and two photodetectors. The new design removes the requirement for high-bandwidth active stabilization present in the previous implementations of the technique, and allows scan rates up to 100 Hz. We demonstrate the spectrometer performance over a wide spectral range by detecting CO around 1575 nm (1.7 THz bandwidth and 6 GHz resolution) and CH around 1650 nm (2.7 THz bandwidth and 13 GHz resolution). We achieve absorption sensitivity of 5 × 10 cm Hz at 1575 nm, and 1 × 10 cm Hz cm at 1650 nm. We discuss the influence of the scanning speed above the adiabatic limit on the amplitude of the absorption signal.
我们展示了一种基于连续滤波游标原理运行的新型稳健腔增强频率梳光谱仪设计。该光谱仪基于一台紧凑型飞秒掺铒光纤激光器、一个中等精细度腔、一个衍射光栅、一个定制的移动孔径以及两个光电探测器。这种新设计消除了该技术先前实现方式中对高带宽有源稳定的要求，并允许高达100 Hz的扫描速率。我们通过检测1575 nm附近的CO（1.7 THz带宽和6 GHz分辨率）以及1650 nm附近的CH（2.7 THz带宽和13 GHz分辨率），展示了该光谱仪在宽光谱范围内的性能。我们在1575 nm处实现了5×10⁻⁹ cm⁻¹ Hz⁻¹/²的吸收灵敏度，在1650 nm处实现了1×10⁻⁸ cm⁻¹ Hz⁻¹/²的吸收灵敏度。我们讨论了高于绝热极限的扫描速度对吸收信号幅度的影响。
