Low threshold current GaAs/InGaAs vertical-cavity surface-emitting laser grown at a constant temperature by molecular beam epitaxy

We report a successful growth of low threshold current GaAs/InGaAs vertical cavity surface emitting lasers (VCSELs) by molecular beam epitaxy (MBE) at a constant temperature which is carefully selected in order not to deteriorate the quality of InGaAs and AlGaAs. The most important advantage of the growth at a constant temperature is the precise control of the thickness of each layer for the whole structure by using an infrared thermometer. It is demonstrated that the threshold current of our samples, patterned 15 x 15 mu m(2), at room temperature continuous wave operation is 700 mu A and the maximum output power is about 800 mu W at a lasing wavelength of 945 nm.