Very Dense Wavelength Beam Combined Laser System
Apparatus, systems and methods to spectrally beam combine a group of diode lasers in an external cavity arrangement. A dichroic beam combiner or volume Bragg grating beam combiner is placed in an external cavity to force each of the diode lasers or groups of diode lasers to oscillate at a wavelength determined by the passband of the beam combiner. In embodiments the combination of a large number of laser diodes in a sufficiently narrow bandwidth to produce a high brightness laser source that has many applications including as to pump a Raman laser or Raman amplifier.
1 . A high power, high brightness laser system, comprising:
a. a plurality of laser diodes, each having a power of not less than 0.25 W, wherein each of the plurality of laser diodes is configured to provide a laser beam along a laser beam path;
b. a common external cavity shared by each of the plurality of laser diodes;
c. a collimating optic in the laser beam paths for creating parallel beams from each of the plurality of laser diodes;
d. a beam combination optic in the common external cavity and in the laser beam paths; wherein the beam combination optic determines the wavelength of each laser diode and aligns each laser beam path from the plurality of laser diodes to be co-linear and overlapping in space, whereby a composite output laser beam is provided; and,
e. the spatial brightness of the composite output laser beam is n times the brightness of any single laser diode in the plurality of laser diodes, where spatial brightness is defined as the combined power divided by the aperture-divergence product.
2 - 71 . (canceled)