Light induced tuning of quantum cascade lasers

摘要

A method for tuning the emission of a midinfrared quantum cascade laser using ultraviolet light is presented. The method uses a quantum cascade laser where a photochromic material is deposited as the top waveguide cladding. Changing the state of the cladding causes variations in the absorbance of the cladding. Wavelength dependent changes in the waveguide losses occur, forcing the laser to emit at a wavelength correlated with an absorbance minimum of the cladding. A blueshift by about 6 cm"1 was obtained at room temperature under UV irradiation which was fully reversed by exposure to visible light or room temperature relaxation.