Soboń Grzegorz, Martynkien Tadeusz, Mergo Paweł, Rutkowski Lucile, Foltynowicz Aleksandra
Opt Lett. 2017 May 1;42(9):1748-1751. doi: 10.1364/OL.42.001748.
We demonstrate a broadband mid-infrared (MIR) frequency comb source based on difference frequency generation (DFG) in periodically poled lithium niobate crystal. MIR radiation is obtained via mixing of the output of a 125 MHz repetition rate Yb-doped fiber laser with Raman-shifted solitons generated from the same source in a highly nonlinear fiber. The resulting idler is tunable in the range of 2.7-4.2 μm, with average output power reaching 237 mW and pulses as short as 115 fs. The coherence of the MIR comb is confirmed by spectral interferometry and heterodyne beat measurements. Applicability of the developed DFG source for laser spectroscopy is demonstrated by measuring absorption spectrum of acetylene at 3.0-3.1 μm.
我们展示了一种基于周期极化铌酸锂晶体中的差频产生（DFG）的宽带中红外（MIR）频率梳源。通过将重复频率为125 MHz的掺镱光纤激光器的输出与在高非线性光纤中由同一光源产生的拉曼频移孤子进行混频，获得中红外辐射。产生的闲频光在2.7 - 4.2μm范围内可调谐，平均输出功率达到237 mW，脉冲短至115 fs。通过光谱干涉测量和外差拍频测量证实了中红外频率梳的相干性。通过测量乙炔在3.0 - 3.1μm处的吸收光谱，证明了所开发的差频产生源在激光光谱学中的适用性。
