Silicon Nanowaveguide Research Articles

Optical time lens based on four-wave mixing on a silicon chip

We propose a new technique to realize an optical time lens for ultrafast temporal processing that is based on four-wave mixing in a silicon nanowaveguide. The demonstrated time lens produces more than 100 pi of phase shift, which is not readily achievable using electro-optic phase modulators. Using this method we demonstrate 20x magnification of a signal consisting of two 3 ps pulses, which allows for temporal measurements using a detector with a 20 GHz bandwidth. Our technique offers the capability of ultrafast temporal characterization and processing in a chip-scale device.

Signal regeneration using low-power four-wave mixing on silicon chip

To meet the increasing demand for higher capacity in optical communications, signal transmission at higher modulation rates and over a broader wavelength range will be required. Signal degradation in the optical channel caused by dispersion, nonlinearity and noise becomes a critical issue as data rates increase. Thus, it is highly desirable to develop broadband, high-speed regeneration devices1. Recent advances in silicon-on-insulator photonic devices offer the potential for highly integrated, robust opto–electronic architectures, and optical processes such as amplification2,3,4, wavelength conversion5,6,7 and amplitude modulation8,9 have already been demonstrated in such structures. In this work, we demonstrate two regeneration schemes using low-power four-wave mixing in a silicon nanowaveguide and compensate for the effects of poor extinction ratio, dispersive broadening and timing jitter. This capability further expands the range of optical functions that can be incorporated into silicon-compatible photonic devices offering a broadband and integrated solution for regeneration.