Yuan Zhengchao, Fan Xinyu, Xu Bingxin, Zhu Yidai, He Zuyuan
Opt Lett. 2024 Oct 15;49(20):5711-5714. doi: 10.1364/OL.536914.
In this Letter, we propose a high-resolution dual-comb spectroscopy (DCS) in the mid-infrared (MIR) region. A broadband electro-optic frequency comb (EOFC) with a line spacing of 13 GHz is generated in the near-infrared region. The injection locking technique is employed to lock the distributed feedback (DFB) laser to each comb line of the 34 comb lines as the seed laser for the subsequent electro-optic modulation. A dual radio frequency (RF) comb source with a 50 MHz line spacing and a 13 GHz bandwidth drives a single IQ Mach-Zehnder modulator (IQ-MZM), functioning as a single-sideband (SSB) generator and producing a DCS with high spectrum flatness and resolution flexibility. The generated DCS is converted to the MIR region via a nonlinear difference frequency generation (DFG) system. A DCS with a bandwidth of 442 GHz and a resolution of 50 MHz is achieved in the 3.3 µm region, and the figure of merit reaches 2.94×10 in a 183.6 ms measurement time.
在本信函中，我们提出了一种用于中红外（MIR）区域的高分辨率双梳光谱技术（DCS）。在近红外区域产生了线间距为13 GHz的宽带电光频率梳（EOFC）。采用注入锁定技术将分布反馈（DFB）激光器锁定到34条梳状线中的每条梳状线，作为后续电光调制的种子激光器。具有50 MHz线间距和13 GHz带宽的双射频（RF）梳状源驱动单个IQ马赫曾德尔调制器（IQ-MZM），其作为单边带（SSB）发生器，并产生具有高光谱平整度和分辨率灵活性的DCS。所产生的DCS通过非线性差频产生（DFG）系统转换到中红外区域。在3.3 µm区域实现了带宽为442 GHz、分辨率为50 MHz的DCS，并且在183.6 ms的测量时间内品质因数达到2.94×10 。
