Methods and systems for spectral beam-combining
A method of spectral beam-combining an array of fiber optics is disclosed. Each fiber may be coupled to a high-power, wavelength-stabilized, fiber-coupled, diode-laser module and has a fiber-by-fiber pre-selected wavelength. The wavelengths may be chosen such that the array can be spectrally combined on, for example a transmission grating and re-focused into an output fiber. This approach is scalable to, for example, 10 kW power and have a beam quality sufficient for metal cutting applications.
1. A spectral beam combiner system, comprising:
a first electromagnetic energy output device including a first wavelength stabilization device inside the first electromagnetic energy output device and operable to output a first wavelength;
a second electromagnetic energy output device including a second wavelength stabilization device inside the second electromagnetic energy output device and operable to output a second wavelength which is different from the first wavelength;
a first optical device positioned transverse to an optical axis of the spectral beam combiner system that receives a plurality of electromagnetic energy inputs via a plurality of input fibers, wherein at least two of the electromagnetic energy inputs differ in wavelength, and that collimates the electromagnetic energy inputs and emits a collimated electromagnetic energy output;
a grating positioned transverse to the optical axis, and after the first optical device along an optical path, that diffracts at least a portion of the collimated electromagnetic energy output emitted by the first optical device, and emits a collimated diffracted electromagnetic energy output; and
a second optical device disposed transverse to the optical axis, and after the grating along an optical path, that focuses the collimated diffracted electromagnetic energy output and generates a focused electromagnetic energy output including the first wavelength and the second wavelength at a single focal point.
2. The spectral beam combiner system of claim 1 , further comprising a plurality of multimode fibers optically coupled to the first optical device, wherein the first optical device receives the plurality of electromagnetic energy inputs via the plurality of multimode fibers.
3. The spectral beam combiner system of claim 2 , wherein a first one of the plurality of multimode fibers is coupled to a first fiber coupled module and a second one of the plurality of multimode fibers is coupled to a second fiber coupled module.
4. The spectral beam combiner system of claim 2 , further comprising a substrate, wherein each of the plurality of multimode fibers is positioned on the substrate such that a predetermined center-to-center distance between at least two of the plurality of multimode fibers is maintained.
5. The spectral beam combiner system of claim 1 , further comprising a plurality of single mode fibers optically coupled to the first optical device, wherein the first optical device receives the plurality of electromagnetic energy inputs via the plurality of single mode fibers.
6. The spectral beam combiner system of claim 5 , wherein a first one of the plurality of single mode fibers is coupled to a first diode laser and a second one of the plurality of single mode fibers is coupled to a second diode laser.
7. The spectral beam combiner system of claim 1 , further comprising an output optical fiber positioned after the second optical device, along an optical path, that receives the focused electromagnetic energy output, and wherein the output optical fiber is a multimode fiber.
8. The spectral beam combiner system of claim 1 , further comprising a plurality of optical fibers, wherein the plurality of electromagnetic energy inputs is received via the plurality of optical fibers.
9. The spectral beam combiner system of claim 8 , further comprising a substrate, wherein the plurality of optical fibers is positioned on the substrate.
10. The spectral beam combiner system of claim 9 , wherein a plurality of recesses is formed in a first surface of the substrate.
11. The spectral beam combiner system of claim 9 , wherein the plurality of electromagnetic energy inputs emitted by each of the plurality of optical fibers comprises electromagnetic energy having a wavelength that is selected from a range of wavelengths between and including 400 nm and 1000 nm.
12. The spectral beam combiner system of claim 1 , wherein the grating is disposed at an angle of 45 degrees with respect to the optical axis.
13. The spectral beam combiner system of claim 1 , further comprising a third optical element disposed transverse to the optical axis and positioned between the grating and the second optical device, wherein the third optical element shapes at least a portion of the collimated diffracted electromagnetic energy output.
14. The spectral beam combiner system of claim 1 , wherein the grating comprises a diffraction grating that diffracts at least a portion of the collimated electromagnetic energy output at an angle that is selected from a range of angles between and including 45 degrees and 135 degrees.
15. The spectral beam combiner system of claim 14 , further comprising a first electromagnetic energy source and a second electromagnetic energy source, and wherein the first electromagnetic energy source is coupled to a first one of the plurality of input fibers and the second electromagnetic energy source is optically coupled to a second one of the plurality of input fibers.
16. The spectral beam combiner system of claim 15 , wherein the first electromagnetic energy source is a fiber coupled module.
17. The spectral beam combiner system of claim 16 , wherein the fiber coupled module is a wavelength-stabilized electromagnetic radiation source.
18. The spectral beam combiner system of claim 15 , further comprising a power supply coupled to the first electromagnetic energy source and the second electromagnetic energy source.
19. The spectral beam combiner system of claim 15 , further comprising a heat exchange surface thermally coupled to the first electromagnetic energy source and the second electromagnetic energy source, wherein the heat exchange surface removes at least a portion of a thermal energy generated by the first electromagnetic energy source and the second electromagnetic energy source.
20. The spectral beam combiner system of claim 14 , wherein the plurality of electromagnetic energy inputs emitted by each of the input fibers included in the plurality of input fibers comprises electromagnetic energy having wavelengths that are selected from a range of wavelengths between and including 800 nm and 1000 nm.