Discrete Mode Laser Diodes: Design Equations and Applications in Nonlinear Optics

Frequency selective structures, in particular gratings, are useful to create single-mode laser diodes, however they introduce losses which can be detrimental for many applications. A theoretical framework to design Discrete Mode Laser Diodes (DMLDs) using gratings with the lowest loss possible while still achieving single-mode operation, is developed. A version of DMLDs using surface gratings is then designed and fabricated in Bragg reflection lasers (BRLs), which support second order nonlinear conversion within the laser cavity. These DMLDs show single mode operation with $>$ 40 dB SMSR, and 0.22 nm/mA, and 0.49 nm/ $^\circ$ C current and temperature tunability. Difference frequency generation with 59.8%W $^{-1}$ cm $^{-2}$ efficiency is then performed to demonstrate the ability of the DMLD to support parametric optical processes within diode laser cavities.