Ultrashort optical pulse wavelength conversion by moving grating of refractive index in semiconductor

All-optical wavelength converters are expected to become key components in future broadband networks. Several techniques have been proposed to achieve wavelength conversion in fiber-optic links such as direct electro-optic and all-optical wavelength conversions. All-optical wavelength converters enable direct translation of the information on the incoming wavelength to a new wavelength without entering the electrical domain. It is well known that optical and microwave wavelength conversion can be realized by using media with time-varying parameters and the Doppler effect. The application of this phenomenon in a semiconductor optical waveguide is attractive because a moving stepwise ionization front (or excited Bragg grating) can be easily realized by well-known means