Chip-scale electrically pumped optical frequency combs (OFCs) are expected to play a fundamental role in applications ranging from telecommunications to optical sensing. To date, however, the availability of such sources around 2 $\mathrm{\mu }$m has been scarce. Here, we present a frequency-modulated OFC operating around 2060 nm of wavelength exploiting the inherent gain nonlinearity of single-section GaSb-based quantum well diode lasers. A 2 mm long device operating as a self-starting comb outputs 50 mW of optical power over more than 10 nm of bandwidth while consuming <1 W of electrical power. Using the shifted-wave interference Fourier transform spectroscopy technique, we characterize the generated frequency-modulated waveform and demonstrate a linearly chirped intermodal phase relationship among the entire emission optical bandwidth. Furthermore, by compensating for the linear chirp using a single-mode optical fiber with opposite dispersion, 6 ps long optical pulses are generated. The frequency stability of the devices with ∼19.3 GHz repetition rates allows us to perform mode-resolved free-running dual-comb spectroscopy. All rights reserved.

中文翻译：

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波长为2μm的调频二极管激光器频率梳

芯片级电泵浦光学频率梳（OFC）有望在从电信到光学传感的各种应用中发挥重要作用。迄今为止，此类资源的可用性约为2$\mathrm{\mu }$米已经稀缺。在这里，我们介绍了利用单节基于GaSb的量子阱二极管激光器的固有增益非线性，在2060 nm波长附近工作的调频OFC。一个2毫米长的设备用作自启动梳，在超过10 nm的带宽上输出50 mW的光功率，而消耗的功率不到1W。使用移波干涉傅立叶变换光谱技术，我们表征了生成的调频波形，并证明了整个发射光带宽之间的线性chi联运态相位关系。此外，通过使用具有相反色散的单模光纤补偿线性chi，会产生6 ps长的光脉冲。器件的频率稳定性约为19。3 GHz的重复频率使我们能够执行模式解析的自由运行双梳状光谱。版权所有。