Light source module
A light source module includes: laser light sources; parallel light lenses that converts laser beams from the laser light sources to collimated laser beams; a demagnification optical system including that demagnifies the collimated laser beams; an optical fiber; and a condenser lens that converges and couples the laser beams demagnified by the demagnification optical system with the optical fiber; wherein an Abbe number of each of the parallel light lenses is set to a set value suppressing an output fluctuation from the optical fiber to a predetermined value or less, the set value determined based on: a transverse magnification defined by a focal length of a corresponding one of the parallel light lenses, a demagnification of the demagnification optical system, and a focal length of the condenser lens; and a corresponding one of wavelength shifts of the laser beams generated by the laser light source.
1. A light source module comprising:
laser light sources configured to emit laser beams;
parallel light lenses configured to convert the laser beams from the laser light sources to collimated laser beams;
a demagnification optical system including a convex lens and a concave lens, configured to demagnify the collimated laser beams;
an optical fiber; and
a condenser lens configured to converge and couple the laser beams demagnified by the demagnification optical system with the optical fiber; wherein
an Abbe number of each of the parallel light lenses is set to a set value suppressing an output fluctuation from the optical fiber to a predetermined value or less, the set value determined based on: a transverse magnification defined by a focal length of a corresponding one of the parallel light lenses, a demagnification of the demagnification optical system, and a focal length of the condenser lens; and a corresponding one of wavelength shifts of the laser beams generated by the laser light sources.
2. The light source module according to claim 1 , wherein
the laser light sources comprise diode lasers having a wavelength from 0.3 μm to 0.55 μm.
3. The light source module according to claim 1 , wherein
the parallel light lenses comprise collimator lenses.
4. The light source module according to claim 2 , wherein
the parallel light lenses comprise collimator lenses.
5. A light source module comprising:
laser light sources configured to emit laser beams;
parallel light lenses configured to convert the laser beams from the laser light sources to collimated laser beams;
an optical fiber; and
a condenser lens configured to converge and couple the collimated laser beams with the optical fiber; wherein
an Abbe number of each of the parallel light lenses is set to a set value suppressing an output fluctuation from the optical fiber to a predetermined value or less, the set value determined based on: a transverse magnification defined by a focal length of a corresponding one of the parallel light lenses and a focal length of the condenser lens; and a wavelength shifts of a corresponding one of the laser light sources, and
the parallel light lenses comprise collimator lenses.
6. The light source module according to claim 5 , wherein
each of the collimator lenses comprises:
a FAC lens configured to convert the laser beam from the corresponding one of the laser light sources to a collimated laser beam in a plane including a fast-axis direction, and
a SAC lens configured to convert the laser beam from the corresponding one of the laser light sources to a collimated laser beam in a plane including a slow-axis direction.
7. The light source module according to claim 1 , wherein the Abbe numbers of the parallel light lenses are set to a following value:
vd> 138.55×(α/ d )−5.6354 when Δλ>1.5×10 −3 μm, (1)
vd> 96.44×(α/ d )−3.3878 when 1.0 nm<Δλ≤1.5×10 −3 μm, (2)
vd> 76.22×(α/ d )−4.007 when 0.75 nm<Δλ≤1.0×10 −3 μm, (3)
vd> 66.19×(α/ d )−11.823 when 0<Δλ≤0.5×10 −3 μm, (4)
wherein vd denotes the Abbe numbers, α denotes the transverse magnification, d denotes a diameter of a core of the optical fiber, and Δλ denotes the wavelength shift of the corresponding one of the laser light sources.
8. The light source module according to claim 2 , wherein the Abbe numbers of the parallel light lenses are set to a following value:
vd> 138.55×(α/ d )−5.6354 when Δλ>1.5×10 −3 μm, (1)
vd> 96.44×(α/ d )−3.3878 when 1.0 nm<Δλ≤1.5×10 −3 μm, (2)
vd> 76.22×(α/ d )−4.007 when 0.75 nm<Δλ≤1.0×10 −3 μm, (3)
vd> 66.19×(α/ d )−11.823 when 0<Δλ≤0.5×10 −3 μm, (4)
wherein vd denotes the Abbe numbers, α denotes the transverse magnification, d denotes a diameter of a core of the optical fiber, and Δλ denotes the wavelength shift of the corresponding one of the laser light sources.
9. The light source module according to claim 3 , wherein the Abbe numbers of the parallel light lenses are set to a following value:
vd> 138.55×(α/ d )−5.6354 when Δλ>1.5×10 −3 μm, (1)
vd> 96.44×(α/ d )−3.3878 when 1.0 nm<Δλ≤1.5×10 −3 μm, (2)
vd> 76.22×(α/ d )−4.007 when 0.75 nm<Δλ≤1.0×10 −3 μm, (3)
vd> 66.19×(α/ d )−11.823 when 0<Δλ≤0.5×10 −3 μm, (4)
wherein vd denotes the Abbe numbers, Δ denotes the transverse magnification, d denotes a diameter of a core of the optical fiber, and Δλ denotes the wavelength shift of the corresponding one of the laser light sources.
10. A light source module comprising:
light source modules according to claim 1 as light source module units;
a second parallel light lenses configured to convert the laser beam from the laser light sources to second collimated laser beams;
a second optical fiber; and
a second condenser lens configured to converge and couple the second collimated laser beams with the second optical fiber.
11. A light source module comprising:
light source modules according to claim 5 as light source module units;
a second parallel light lenses configured to convert the laser beam from the laser light sources to second collimated laser beams;
a second optical fiber; and
a second condenser lens configured to converge and couple the second collimated laser beams with the second optical fiber.
12. A light source module according to claim 10 , wherein
an Abbe number of each of the second parallel light lenses is set to a second set value suppressing an output fluctuation from the second optical fiber to a predetermined value or less, the second set value determined based on: a transverse magnification defined by a focal length of a corresponding one of the second parallel light lenses and a focal length of the c second condenser lens; and a wavelength shift of a corresponding one of the light source module units.
13. A light source module according to claim 11 , wherein
an Abbe number of each of the second parallel light lenses is set to a second set value suppressing an output fluctuation from the second optical fiber to a predetermined value or less, the second set value determined based on: a transverse magnification defined by a focal length of a corresponding one of the second parallel light lenses and a focal length of the c second condenser lens; and a wavelength shift of a corresponding one of the light source module units.
14. The light source module according to claim 5 , wherein
the laser light sources comprise diode lasers having a wavelength from 0.3 μm to 0.55 μm.