Continuous-wave operation of long-cavity m-plane GaN-based vertical-cavity surface-emitting lasers with a topside curved mirror and nanoporous GaN DBR

We demonstrate long cavity (60.5 ) GaN-based vertical-cavity surface-emitting lasers (VCSELs) with a topside curved monolithic GaN lens, a buried tunnel junction (BTJ) current aperture, and a bottomside nanoporous GaN distributed Bragg reflector (DBR). Under pulsed operation (1% duty cycle, 1μs pulse), a VCSEL with a 9μm diameter aperture had a threshold current density of 6.6kA/cm², a maximum output power of 3mW, and a differential efficiency of 5.6% for a lasing mode at 411nm. Under CW operation, the threshold current density was 7.3kA/ cm2, the differential efficiency was 2.8%, and a peak output power of 1.1mW at rollover was reached. Preliminary farfield patterns are presented and discussed.