Degenerate Four-Wave Mixing in Si Quantum Dot Doped Si-Rich SiNx Channel Waveguide

The degenerate four-wave-mixing (DFWM) effect in Si quantum dot doped SiNx (SiN
_x
:Si-QD) channel waveguide has been preliminarily demonstrated. By enhancing the optical nonlinearity of SiN
_x
at 1550 nm with doped Si-QDs, the DFWM can be enhanced with its conversion efficiency of -46 dB in the SiN
_x
:Si-QD channel waveguide with length of 8 mm. The nonlinear refractive index of the SiN
_x
:Si-QD is estimated to be 3 × 10-14cm2/W. The chromatic dispersion analysis indicates that the SiN
_x
:Si-QD channel waveguide exhibits 3-dB conversion bandwidth of larger than 16 nm. Such a SiN
_x
:Si-QD waveguide is free of multi-photon absorption at 1550 nm even when injecting an intense laser pulse as large as 1.3 GW/cm
²
. These results show great potential of Si-QD doped SiN
_x
waveguide for nonlinear optical processing.