Near-field optical study of AlGaN/GaN quantum-well waveguide

摘要

Ultraviolet near-field scanning microscopy and near-field spectroscopy have been employed to study the optical properties of AlGaN/GaN quantum-well waveguides. The divergence of the spontaneous emission emerging from the waveguide exit port was measured. The near-field optical image revealed a half-angle in-plane divergence of 6° and vertical divergence of 40°. Optical loss of the spontaneous emission inside the waveguide at λ=350 nm was found to be 106 cm~(-1). These parameters are important for the achievement of future III-nitride photonic integrated circuits for various applications.