Characterization of 850nm-15μm GaAs/AlGaAs quantum-well vertical cavity surface emitting lasers (VCSELs) prepared by gas sourse molecular beam epitaxy

Abstract

In this report, operating characteristics and performance of 15μm diameter vertical cavity surface emitting lasers (VCSELs) emitting at 850nm and fabricated by gas source molecular beam-epitaxy (GSMBE) is presented. The device characterisation is performed by observing the continuous wave (cw) operation under room temperature. Threshold currents (I_th) of 6.5mA and 7.5mA were observed for the two devices observed. A polarisation characteristic is also studied. Polarisation switching is quite evident at higher bias currents. The second device shows polarisation dominance in the orthogonal direction over a range of lasing wavelength of 852 to 852.5nm. Despite the excellent stability effects exhibited by the device, higher order modes begin to lase at higher bias currents.

Keywords: Beam, Quantum, Laser, Wavelength, Laser, Molecular Beam