ABSTRACT

Compared with an edge-emitting laser diode, VCSEL possesses a number of major distinctive advantages: (1) ultralow threshold

as a result of small cavity volume due to a cavity length typically with only a few micrometers; (2) completely circular field pattern; (3) single mode emission; (4) small beam divergence; (5) high speed modulation (>10 GHz) due to large relaxation frequency; (6) enhanced non-linear conversion; (7) facilitating fabrication of 2D laser array. As a result of the above superior properties compared with conventional edge-emitting lasers, VCSEL is a highly favorable lighting source, in particular, for application of high density information storage and high resolution laser printing.