High energy semiconductor laser
A high energy semiconductor laser capable of high optical efficiency includes a master oscillator coupled to a plurality of slave oscillators, each producing a laser beam that is substantially at the same wavelength as the output beam from the master oscillator. The outputs of the slave oscillators are then coherently combined to a single monochromatic beam having an optical power which is substantially greater than that of beam output from the master oscillator. The slave oscillators can be configured as ring resonators. A suitable ring oscillator can be built by arranging one or more semiconductor diode laser gain media, two or more reflecting mirrors, and at least one semireflective mirror in a ring configuration. A suitable ring oscillator can also be built by machining a solid block to include one or more semiconductor diode laser high gain regions.
1. A semiconductor laser comprising:
a master oscillator configured to emit a first stage laser beam,
an optical amplifier configured to receive and add optical power to the first stage laser beam producing a second stage beam,
a plurality of ring resonators, each configured as a regenerative amplifier to receive a portion of the second stage laser beam along a first direction, add optical power to the portion of the second stage laser beam, and emit a third stage laser beam along a second direction, wherein the second stage laser beam and the third stage laser beam have substantially identical wavelengths and phase, each ring resonator comprising a gain region of at least one semiconductor laser diode, a semireflective mirror configured to receive an input beam along the first direction and emit an output beam along the second direction, a plurality of reflecting mirrors wherein each gain medium is disposed between two of the reflecting mirrors, wherein the semireflective mirror and reflective mirror form a circulating optical path which passes through at least one gain medium, and
a beam combiner configured to receive and coherently combine into a single monochromatic laser beam at least two of the third stage laser beams.
2. A semiconductor laser comprising:
a master oscillator configured to emit a first stage laser beam,
an optical amplifier configured to receive and add optical power to the first stage laser beam producing a second stage laser beam,
a plurality of ring resonators, each configured as a regenerative amplifier to receive a portion of the second stage laser beam along a first direction, add optical power to the portion of the second stage laser beam, and emit a third stage laser beam along a second direction, wherein the second stage laser beam and the third stage laser beam have substantially identical wavelengths and phase, each ring resonator comprising a solid block of gallium arsenide having at least one coupling facet configured to partially transmit light and a plurality of internally reflective facets wherein when the second stage laser beam passes through the coupling facet along the first direction, and the remaining facets are configured to circulate the second stage beam within the solid block,
a plurality of evanescent-wave output couplers each optically coupled to the coupling facet of one of the ring resonators and configured to transmit the second stage laser beam through the coupling facet into the solid block along the first direction and receive the third stage beam from the solid block through the coupling facet along the second direction, and
a beam combiner configured to receive and coherently combine into a single monochromatic laser beam at least two of the third stage laser beams.