Precise Lateral Mode Control in Photonic Crystal Vertical-Cavity Surface-Emitting Lasers

We demonstrate an oscillatory behavior of resonant wavelengths and threshold gains of the fundamental and first-order transverse mode of photonic crystal vertical-cavity surface-emitting laser (PhC VCSEL) with the PhC etching depth. To this aim we use a full vectorial, 3-D optical model (plane wave admittance method) combined with a thermal model and an exemplary 1300 nm quantum-dot VCSEL structure. Such oscillatory behavior poses a strong restriction on the etching depth precision: about 0.1 μm in order to achieve a threshold gain not higher than 10% the threshold gain minimum and twice higher precision for simultaneous strong discrimination of the first-order transverse mode.