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Nonlinear silicon photonics has been an immense research subject in the past several years with promising prospects of
delivering chip scale signal modulation, shaping and characterization tools. In particular, broadband parametric process
has been considered for applications ranging from wideband light amplifiers to signal characterization and signal
shaping tools. Although underlying nonlinear effect, Kerr phenomena, in silicon has generated promising result of
wavelength conversion, the success of these devices have been challenged by the presence of nonlinear losses such as
two photon absorption and the two photon generated free carrier absorption. Experimental demonstrations were limited
to conversion efficiencies below -10dB. Here, we present the prospect of ultra wide discrete band conversion schemes
and the prospect of parametric process at mid-infrared wavelengths where nonlinear losses are not present. In particular,
we explore the parametric wavelength conversion scheme at mid-wave infrared wavelength (2μm~6μm) by four-wavefixing
process in silicon waveguides with new cladding materials, such as sapphire, that can provide transparency up to
6μm and facilitate phase matching condition for discrete wavelength bands as far as 60THz away from each other.
Design criteria include the optimization of mode overlap integrals and dispersion engineering for an ultra-wide band
signals. The particular results of wavelength conversion between 2μm bands and 5μm bands, and between 1.8μm bands
and >4μm bands will be presented. Prospects of frequency band conversion in generation of new infrared signals and
low noise, room temperature detection of mid-infrared signals will also be discussed.
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