A 1.5-mu m wavelength superluminescent light source operating at a heat sink temperature of 13 degrees C with the following properties was realized: 20-mW continuous wave output power, 130-nm spectral bandwidth, and 0.2-dB spectral modulation. This light source consists of an angled facet single-mode waveguide with a rear absorption region. These results were obtained by optimizing the epitaxial design, the waveguide design, and the device mounting.