First order distributed feedback operation in ZnSe based laser structures

First order distributed feedback laser with periods down to 94 nm based on ZnSe have been realized by electron beam lithography and wet chemical etching. Distributed feedback operation was demonstrated by optical excitation using a pulsed N2 laser. A threshold density of 80 kW/cm2 was found at room temperature for a resonator length of 225 μm. From the stop band width, a coupling coefficient of 120 cm−1 can be estimated. By varying the grating period the emission wavelength can be tuned over a wide spectral range of more than 130 meV. Measurements in the range between 20 and 300 K show that the shift of the emission wavelength with temperature is reduced by more than a factor of four as compared to the temperature shift of the spontaneous emission.