Optical frequency combs have emerged as an important tool enabling diverse applications from test-and-measurement, including spectroscopy, metrology, precision distance measurement, sensing, as well as optical and microwave waveform synthesis, signal processing, and communications. Several techniques exist to generate optical frequency combs, such as mode-locked lasers, Kerr micro-resonators, and electro-optic modulation. Important characteristics of optical frequency combs include the number of comb lines, their spacing, spectral shape and/or flatness, and intensity noise. While mode-locked lasers and Kerr micro-resonators can be used to obtain a large number of comb lines compared to electro-optic modulation, the latter provides increased flexibility in tuning the comb spacing. For some applications in optical communications and microwave photonics, a high degree of integration may be more desirable over a very large number of comb lines. In this paper, we review recent progress on integrated electro-optic frequency comb generators, including those based on indium phosphide, lithium niobate, and silicon photonics.

光学频率梳已成为一种重要工具，可实现测试和测量的各种应用，包括光谱学、计量学、精密距离测量、传感，以及光学和微波波形合成、信号处理和通信。有几种技术可以产生光学频率梳，例如锁模激光器、克尔微谐振器和电光调制。光频梳的重要特性包括梳线的数量、它们的间距、光谱形状和/或平坦度以及强度噪声。虽然与电光调制相比，锁模激光器和克尔微谐振器可用于获得大量梳状线，但后者在调整梳状间距方面提供了更大的灵活性。对于光通信和微波光子学中的一些应用，在非常大量的梳状线上可能更需要高度集成。在本文中，我们回顾了集成电光频率梳发生器的最新进展，包括基于磷化铟、铌酸锂和硅光子学的电光频率梳发生器。