Ryan Anderson Graduate Student Researcher, DenBaars Group
University of California, Santa Barbara
Nano-Porous GaN in Edge Emitting Laser Diodes
Ryan Anderson, Haojun Zhang, Emily Trageser, Dan Cohen, Steven DenBaars
Materials Department, University of California, Santa Barbara, California, USA
GaN based edge emitting laser diodes typically use AlGaN or InGaN for index contrast and mode confinement in waveguide cladding layers. Though growing on GaN semi-polar planes is expected to supply higher gain than the conventional c-plane, the formation of misfit dislocations on these planes limits the possible AlGaN/InGaN thickness and composition. High composition AlGaN can also lead to higher voltage operation and reduced lifetime. Nano-porous GaN is a lattice matched, high index contrast material that has recently been investigated as a replacement to AlGaN and InGaN for optical confinement. This opens up new design possibilities to improve power and efficiency in edge emitters, especially at longer wavelength emission.
Electrically injected lasers have been fabricated using nano-porous cladding for blue and green emission wavelengths. Optical loss due to scattering at pores will be discussed as limiting power and efficiency of the fabricated blue lasers. Green lasers have shown comparable performance to traditional green LDs from this group, with lower power but improved operating voltage, serving as a stepping stone to broadening applicable wavelengths of III-N LDs.