Highly Flat Optical Frequency Comb Based On The Time Lens Principle

Broad bandwidth optical frequency combs (OFCs) have received much attention in recent years due to a dramatic growth of their applications, such as spectroscopy measurements, microwave photonics applications, and optical communications. There are several advanced optical superchannel systems, which have been practically implemented by OFCs, such as a Tbit/s coherent optical orthogonal frequency division multiplexing (OFDM) system [1] and Tbit/s single-channel coherent Nyquist pulse transmission systems with high spectral efficiency [2], etc. Those systems require the OFC with a high degree of flatness and broad bandwidth that are difficult to achieve with conventional methods based on sinusoidal phase modulation (SPM).