$(In,Ga)N∕GaN$ microcavities with double dielectric mirrors fabricated by selective removal of an (Al,In)N sacrificial layer

Comparable microcavities with $3λ∕2$ $(∼240nm)$ active regions containing distributed (In,Ga)N quantum wells, grown on GaN substrates and bounded by two dielectric mirrors, have been fabricated by two different routes: one using laser lift-off to process structures grown on GaN-on-sapphire templates and the second using freestanding GaN substrates, which are initially processed by mechanical thinning. Both exploit the properties of an $Al0.83In0.17N$ layer, lattice matched to the GaN substrate and spacer layers. In both cases cavity quality factors $>400$ are demonstrated by measurements of the cavity-filtered room-temperature excitonic emission near $410nm$⁠.