Data are presented characterizing a new process for fabrication of vertical-cavity surface-emitting lasers based on the selective conversion of high Al composition epitaxial AlGaAs to a stable native oxide using ‘‘wet oxidation.’’ The native oxide is used to form a ring contact to the laser active region. The resulting laser active regions have dimensions of 8, 4, and 2 μm. The lowest threshold laser is achieved with the 8-μm active region, with a minimum threshold current of 225-μA continuous wave at room temperature.

No abstract

Data are presented characterizing the transverse mode behavior of AlAs/GaAs/InGaAs vertical-cavity surface-emitting lasers fabricated using a native-oxide process. The native-oxide process results in laser diodes with active regions defined to be 10, 8, and 4 μm squares. We show that the transverse lasing mode is influenced by mirror reflectivity, with significant mode changes occurring with drive current for 8–10 μm devices in the ranges of one to four times threshold. In smaller devices of 4 μm square dimension, the transverse mode at threshold appears as a lowest order mode.

Data are presented demonstrating a strong influence of a closely spaced AlAs/GaAs distributed Bragg reflector on the spontaneous emission characteristics of an InGaAs-GaAs quantum well. The mirror to quantum well spacings on different crystal samples correspond to optical path lengths of either 1/4, 1/2, or 3/4 of the emission wavelength. The samples are characterized using photoluminescence, electroluminescence, and reflectivity measurements. Spontaneous emission is found to be greatly enhanced for a 1/2 wavelength spacing, while 1/4 and 3/4 spacings suppress the spontaneous emission by a factor of ≳1000.

No abstract