Theoretical investigation on THz wavelength conversion based on four-wave mixing in QWS-DFB-LD

Abstract

By using the coupled mode equations, the characteristics of THz wavelength converter based on four-wave mixing (FWM) in λ/4 phase-shifted distributed feedback laser diode (QWS-DFB -LD) are analyzed. The numerical simulation indicates that, larger biasing current and smaller detuning expand the dynamic range of conversion efficiency and extinction ratio, but worsen the frequency chirp. Due to the lasing effect, the peak modulation frequency of extinction ratio and chirp occur at the relaxation oscillation frequency. Good conversion characteristics can be obtained by selecting system parameters reasonably. This configuration would have potentials in optics communications because of its wide-band, high-speed and without pump input.