Light source device and direct diode laser system
A light source device including: a first light source configured to coaxially combine a plurality of first laser beams, each having a peak wavelength within a first wavelength range, to thereby generate and emit a first wavelength-combined beam; a second light source configured to coaxially combine a plurality of second laser beams, each having a peak wavelength within a second wavelength range that defines a range of peak wavelengths shorter than the peak wavelengths in the first wavelength range, to thereby generate and emit a second wavelength-combined beam; and a wavelength filter configured to coaxially combine the first wavelength-combined beam and the second wavelength-combined beam to thereby generate and emit a third wavelength-combined beam.
1. A light source device comprising:
a first light source configured to generate and emit a first wavelength-combined beam, the first light source comprising:
a plurality of first external cavity laser modules configured to emit a plurality of first laser beams, respectively, each of the plurality of first laser beams having a peak wavelength within a first wavelength range, and
a first beam combiner configured to combine the plurality of first laser beams to generate the first wavelength-combined beam;
a second light source configured to generate and emit a second wavelength-combined beam, the second light source comprising:
a plurality of second external cavity laser modules configured to emit a plurality of second laser beams, respectively, each of the plurality of second laser beams having a peak wavelength within a second wavelength range that defines a range of peak wavelengths shorter than the peak wavelengths in the first wavelength range, and
a second beam combiner configured to combine the plurality of second laser beams to generate the second wavelength-combined beam; and
a wavelength filter configured to coaxially combine the first wavelength-combined beam and the second wavelength-combined beam to thereby generate and emit a third wavelength-combined beam.
2. The light source device of claim 1 , wherein:
the wavelength filter is one selected from the group consisting of: a dichroic mirror, a diffractive optical element, and a holographic optical element.
3. The light source device of claim 1 , wherein:
a first optical path length between the first light source and the wavelength filter is longer than a second optical path length between the second light source and the wavelength filter.
4. The light source device of claim 1 , wherein:
a first optical path length is defined between the first light source and the wavelength filter,
a second optical path length is defined between the second light source and the wavelength filter, and
a difference between the first optical path length and the second optical path length is 250 mm or more.
5. The light source device of claim 1 , further comprising:
a lens unit that comprises one or more lenses and is configured to focus the third wavelength-combined beam emitted from the wavelength filter.
6. The light source device of claim 1 , wherein:
the peak wavelengths of respective ones of the plurality of first laser beams differ from one another within the first wavelength range; and
the peak wavelengths of respective ones of the plurality of second laser beams differ from one another within the second wavelength range.
7. The light source device of claim 1 , wherein:
each of the plurality of first external cavity laser modules and each of the plurality of second external cavity laser modules includes a laser diode and an external cavity.
8. The light source device of claim 7 , wherein:
a lasing wavelength of the laser diode is in a range of 350 nm to 550 nm.
9. The light source device of claim 8 , wherein:
the laser diode is accommodated in a semiconductor laser package that is sealed.
10. A direct diode laser system comprising:
a light source device;
an optical fiber; and
a processing head connected to the optical fiber; wherein:
the light source device comprises:
a first light source configured to generate and emit a first wavelength-combined beam, the first light source comprising:
a plurality of first external cavity laser modules configured to emit a plurality of first laser beams, respectively, each of the plurality of first laser beams having a peak wavelength within a first wavelength range, and
a first beam combiner configured to combine the plurality of first laser beams to generate the first wavelength-combined beam,
a second light source configured to generate and emit a second wavelength-combined beam, the second light source comprising:
a plurality of second external cavity laser modules configured to emit a plurality of second laser beams, respectively, each of the plurality of second laser beams having a peak wavelength within a second wavelength range that defines a range of peak wavelengths shorter than the peak wavelengths in the first wavelength range, and
a second beam combiner configured to combine the plurality of second laser beams to generate the second wavelength-combined beam, and
a wavelength filter configured to coaxially combine the first wavelength-combined beam and the second wavelength-combined beam to thereby generate and emit a third wavelength-combined beam; and
the third wavelength-combined beam emitted from the light source device is combined into the optical fiber; and
the processing head is configured to irradiate a target object with the third wavelength-combined beam emitted from the optical fiber.