Monolithic integration of multiple wavelength vertical-cavity surface-emitting lasers by mask molecular beam epitaxy

Mask molecular beam epitaxy has been used to monolithically integrate vertical-cavity surface-emitting lasers (VCSELs) emitting at two wavelengths. This technique allows successive selective and nonselective growth in a chamber by using a movable mask. Varying the cavity thickness at selected areas enables the growth of VCSELs spaced 500 μm apart and emitting at wavelengths 10 nm apart. Both lasers have threshold current densities of 1.3–1.4 kA/cm2, a range comparable to that of typical VCSELs grown by conventional molecular beam epitaxy.