Efficient frequency noise reduction of GaAlAs semiconductor lasers by optical feedback from an external high-finesse resonator

The reduction of frequency noise power level of non-antireflection-coated GaAlAs laser diodes by several orders of magnitude using optical feedback from an external high-finesse Fabry-Perot resonator is discussed. Optimum oscillation parameters were derived from a steady-state model. Long-term performance was obtained by electronic feedback phase control.<>