Various methods, systems, and apparatuses are described in which a light source (101) capable of lasing is wavelength locked by an injected light signal. The light source (101) capable of lasing, such as a Fabry-Perot laser diode, may have antireflective coating on one or more facets of the light source (101) capable of lasing. The light source (101) capable of lasing receives a spectral slice of a light signal from a broadband light source (113) to wavelength lock the output wavelength of the light source (101) capable of lasing within the bandwidth of the injected light signal. A current pump (141) may bias the light source (101) capable of lasing to operate as a reflective regenerate semiconductor optical amplifier so that the injected light is reflected back out a front facet after being amplified and wavelength locked. The current pump (141) may also bias the light source (101) capable of lasing such that the externally injected narrow-band light signal into the light source (101) capable of lasing suppresses the lasing modes outside of the bandwidth of injected incoherent light.