Towards on-chip analog photonic signal processors based on temporal dispersion

Optical signal processing has been demonstrated to surpass the performance of electronics for specific and demanding computations useful for a variety of applications. Implementing these optical processing schemes in on-chip, integrated format is of particular interest to meet requirements for physical footprint, scalability, and integration with current technologies. Many important signal processing functionalities can be efficiently implemented using a combination of temporal and spectral phase manipulations. One relevant example is the time lens spectrogram (TLS), which gives real-time information about the evolving spectrum of an optical or microwave signal over time. The advantage of the TLS is that while electronics can perform millions of Fourier transforms per second over a few GHz of bandwidth, the TLS can accomplish billions of transforms per second over tens to hundreds of GHz. This presentation will provide an overview of this technique, and recent work towards integrated realization of the TLS and related functionalities, including implementation of arbitrary spectral phase filtering, such as highly dispersive lines, on silicon photonic chips.