Design of micro-nano grooves incorporated into suspended GaN membrane for active integrated optics

Micro-nano grooves incorporated into a suspended GaN sheet is proposed for active and passive monolithic integration of silicon based InGaN/GaN blue LEDs. Rigorous finite element method (FEM) simulation is performed to investigate the efficiency of coupling enhancement and regulation effect. The imported efficiency from active source to passive waveguide is significantly improved, especially for small angle incidences and small membrane thickness, due to the active grating coupling effect. The overall imported efficiency increased by 240% in the ±30° incident angle range, and 140% in the ±70° range, with 300 nm membrane thickness and 260 nm grating period. Waveguide gratings exhibit filter and extractor properties respectively at different parameters, realizing direct monolithic modulation to light source. This study demonstrates new possibilities for integrated optics and innovative blue LED integrated applications.