Broad-Band Optical Gain on a Silicon Photonic Chip
One of the critical barriers standing in the way of the creation of integrated photonic chips for future light-based information technologies is the development of silicon-compatible optical components that can simultaneously amplify and process optical signals covering a broad range of wavelengths. This capability would allow many different optical signals, distinguished by their wavelength, to be processed on one small chip. Up to now, researchers have been able demonstrate only devices that amplify one narrow bandwidth of light, or only a single wavelength “channel.” CNS researchers have now shown that by suitably designing silicon waveguides at the nanoscale, it is possible to achieve broadband amplification of light signals by exploiting a optical effect known as “four-wave mixing”. This process also can enable many other all-optical signal-processing functions to be done on a small photonic chip that previously could be achieved only by employing long lengths of optical fiber .
The four-wave mixing process involves the conversion of two pump photons to a signal photon and an “idler” photon. By suitable design, amplification of the optical signal can occur over a broad range of wavelengths.
[Lead CNS Investigator: M. Lipson and A. Gaeta ]
For additional information see:
- M. A. Foster, A. C. Turner, J. E. Sharping, B. S. Schmidt, M. Lipson, and A. L. Gaeta, "Broad-band optical parametric gain on a silicon photonic chip," Nature 441, 960-963 (2006).