Journal of Vacuum Science & Technology B, Vol.24, No.3, 1559-1563, 2006
Fabrication and molecular beam epitaxy regrowth of first-order, high contrast AlGaAs/GaAs gratings
We present a fabrication technique and molecular beam epitaxy (MBE) regrowth of first-order, high contrast AlGaAs/GaAs diffraction gratings for laser emitting at 980 nm. An immersion holography technique is used to uniformly pattern first-order gratings with a pitch of 155 nm. MBE is used to overgrow Al0.75Ga0.25As on etched GaAs gratings. It is found that slow growth rates with optimum arsenic overpressure are necessary to overgrow gratings with low pitting defect densities. These first-order, high contrast gratings are integrated as distributed Bragg reflectors in an edge-emitting laser structure. Single-mode emission at 1 mu m with a side mode suppression ratio greater than 30 dB is demonstrated. (c) 2006 American Vacuum Society.