Narrow-band light emission in a semiconductor-fiber asymmetric waveguide coupler

We have demonstrated a narrow-band, fiber-coupled light emitter based on evanescent coupling between a semiconductor waveguide and a polished single mode fiber. The semiconductor waveguide uses distributed Bragg reflector mirror layers to phase-match to the low index fiber at certain resonant wavelengths. The wavelength selectivity of the emission spectrum is caused by the very different dispersion characteristics of the two waveguides. A minimum linewidth of 1.5 nm is obtained.