Ring lasers

Abstract

Tunable vertical-cavity surface-emitting lasers (VCSEL) provide broad wavelength tuning range at very high modulation speed, but usually employ micro electromechanical systems, which are sensitive to vibrations. In this paper we propose a tunable 1550 nm VCSEL design with enclosed intra-cavity liquid-crystal (LC) cell. The laser is electrically pumped and the wavelength selectivity is obtained by varying LC’s refractive index through electro-optical tuning of the LC director.By performing one-dimensional transfer-matrix optical calculations, supplemented with a fully-vectorial three-dimensional self-consistent modeling of thermal, electrical and optical phenomena, we optimize the design and show the dependency of the emitted wavelength on LC cell thickness and the LC director orientation. The analysis is concluded with a possibility of achieving 68.5 nm tuning range in a continuous-wave operation regime and without polarization or transverse mode switching.