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Green (524 nm) InGaN/GaN laser diodes with nano-porous cladding and deep-ridge waveguiding
Abstract:
III-Nitride edge-emitting laser diodes operating at green wavelengths (λ = 524 nm) with nano-porous GaN cladding are demonstrated under pulsed electrical injection. Device performance is enhanced by employing a deeply etched ridge waveguide combined with atomic layer deposition (ALD) sidewall passivation. Compared to shallow-ridge reference lasers, deep-ridge lasers exhibit higher efficiency and lower loss through a combination of improved lateral carrier confinement and improved porous etch selectivity. Internal loss was reduced from 35 cm-1 to 21 cm-1 calculated from variable stripe length analysis, with a similar loss reduction observed in segmented contact absorption curves. Epitaxial improvements are needed to address high threshold current density (22 kA/cm2) and low injection efficiency (16%), but quasi-continuous-wave operation is demonstrated.
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