A type of diode laser that uses diffraction gratings rather than mirrors to create the resonance and oscillation in the cavity. It produces a finer range of wavelengths than a Fabry- Perot cavity. A distributed Bragg reflection laser is a similar technology that uses Bragg gratings. The other major type of laser uses a Fabry-Perot cavity with mirrors. See Fabry-Perot and fiber Bragg grating.