Tailoring of optical mode profiles of high-power diode lasers evidenced by near-field photocurrent spectroscopy

摘要

Tailoring of optical mode profiles of high-power diode lasers is directly demonstrated by means of near-field photocurrent spectroscopy. Three double barrier separate confinement heterostructures with different confinement geometries are designed and their optical mode profiles are studied both theoretically and experimentally. The near-field spectroscopic results clearly resolve the intended variation in optical mode width. A remaining discrepancy between the designed and experimentally measured mode profiles, manifesting itself in the reduction of their evanescent tails, is attributed to the structure of the antiguiding barrier. The results demonstrate that near-field field photocurrent spectroscopy is a powerful, nondestructive, and quantitative technique for optical waveguide inspection in high-power diode lasers.