Fabrication of InP/air-gap distributed Bragg reflectors and micro-cavities

High reflective Bragg reflectors based on suspended InP-layers were fabricated by selective wet etching. Areas as large as 15 × 20 μm2 could be realized. Two three-period mirrors were employed in a cavity with a 1.3 μm GaInAsP active layer. The spectral reflectivity of the structure exhibits a Fabry Perot resonance at 1.32 μm. When excited with a Nd-YAG laser, the structure generates a narrow emission at the same wavelength and a linewith of ⩽2.5 nm.