Integrated laser-amplifier with steerable beam

A master oscillator power amplifier device comprising,

• a semiconductor diode laser having at least one active region for lightwave generation, electrical pump means for injecting current into said active region to generate said lightwaves, waveguide means for propagation of said lightwaves, and reflector means for providing feedback of said lightwaves,
• amplifier means disposed in tandem with said laser for providing an optical power gain to said lightwaves, said amplifier means including an active region, a waveguide optically coupled to said laser to receive said lightwaves, and means for pumping said active region to amplify said lightwaves, said amplifier means integral with said laser on a common monolithic substrate, and
• a grating output coupler disposed to receive said amplified lightwaves, said coupler having a grating period which is different from any Bragg reflector period providing significant reflection back to said laser, thereby producing a coherent single mode output beam.

A master oscillator power amplifier device comprising,

• a semiconductor diode laser formed on a substrate, the laser having a waveguide supporting propagation of only a single spatial mode, the laser also having a pair of grating reflectors, a rear one of said grating reflectors being characterized by strong frequency selectivity, said laser being wavelength tunable with a variable tuning current injected through said rear reflector,
• a flared index guided waveguide optically coupled to an output of said laser waveguide, said waveguide widening from input to output on an angle less than a divergence angle of light from said laser, said flared waveguide having a broad area electrical contact disposed proximate thereto so as to supply an amplification current thereto, said flared waveguide formed on said substrate monolithically with said laser, and
• a second-order grating disposed to receive amplified light from said flared waveguide, said grating having a period different from that of said grating reflectors, thereby producing a coherent single mode output beam.

A master oscillator power amplifier device comprising,

• a semiconductor diode laser disposed on a substrate, said laser having at least one active region for lightwave generation, a waveguide for propagation of said lightwaves, and a pair of grating reflectors, a rear one of said reflectors being characterized by strong frequency selection, said laser being wavelength tunable with a variable tuning current injected through said rear reflector, and
• a sequential chain of optical amplifiers and grating output couplers disposed in tandem on said substrate, each of said amplifiers including an active region, a waveguide, and means for pumping said active region to amplify said lightwaves, a first of said amplifiers being disposed in tandem with said laser and having said waveguide optically coupled to said laser to receive said lightwaves, the subsequent amplifiers having said waveguide optically coupled to a preceding grating output coupler, each grating output coupler being disposed to receive amplified lightwaves from a preceding amplifier, each grating output coupler having a grating period different from that of said grating reflectors of said laser, each grating output coupler thereby producing a coherent single mode output beam.