Monolithic transmitting spectral beam combiner
View Patent ↗A device utilized for spectrally combining multi lasers or laser emitters into a single high-power beam. Exemplary embodiments of the device consist of a monolithic structure, such as a hollow tube, wherein the input end cap comprises a transform optic and the output end cap comprises a transmission grating.
1. A transmitting spectral beam combiner (SBC), comprising:
a hollow structure having an input end and an output end;
a first transform optic fixedly attached to seal said input end; and
a first transmission grating fixedly attached to seal said output end,
wherein an internal area of said hollow structure is sealed, wherein said grating comprises a first periodic structure located within said internal area, and
wherein out facing surfaces of said first transform optic and said first transmission grating utilize bulk microstructures or a thin film coating to minimize Fresnel reflection losses.
2. The SBC of claim 1 , wherein said hollow structure is selected from the group consisting of a hollow tube, a hollow cylinder and a hollow square.
3. The SBC of claim 1 , wherein said first transmission grating consists essentially of bulk fused silica material.
4. The SBC of claim 1 , wherein said hollow structure comprises highly conductive material.
5. The SBC of claim 4 , wherein said highly conductive material is selected from the group consisting of silicon and silicon carbide.
6. The SBC of claim 1 , wherein said hollow structure comprises a non-absorbing material.
7. The SBC of claim 6 , wherein said non-absorbing material comprises fused silica.
8. The SBC of claim 1 , wherein said first transform optic is selected from the group consisting of an aspheric lens, a plano-convex lens and a Fresnel lens.
9. The SBC of claim 1 , wherein said first transmission grating is polarization insensitive for wavelengths from 1025 nm to 1085 nm with a theoretical transmitted diffraction efficiency >99%.
10. The SBC of claim 9 , wherein said first transmission grating has a period >900 nm and <1200 nm, a grating depth >1000 nm and <3000 nm and a grating duty cycle of >0.5 and <0.8.
11. The SBC of claim 1 , wherein said first periodic structure has no thin film.
12. The SBC of claim 1 , wherein said internal area comprises an inert gas.
13. The SBC of claim 1 , wherein said internal area comprises one of argon or a nitrogen/oxygen mixture.
14. The SBC of claim 1 , wherein said internal area is under vacuum to compensate for various pressures.
15. The SBC of claim 1 , wherein said hollow structure includes a see-through window that allows for a line of sight that is colinear with combined laser outputs.
16. The SBC of claim 1 , further comprising means for directing an input array of beams onto said first transform optic, wherein said input array of beams is selected from the group consisting of a one-dimensional array of beams and a two-dimensional array of beams.
17. A method, comprising:
providing the SBC of claim 1 ; and
directing a plurality of beams having different wavelengths so that they overlap on said first transform optic, overlap on said first transmission grating and produce a single output beam.
18. The method of claim 17 , wherein said plurality of beams is configured as one of a one-dimensional array or a two-dimensional array.
19. A method, comprising:
providing the SBC of claim 1 ; and
directing a plurality of beams having different wavelengths so that they do not overlap on said first transform optic, do not overlap on said first transmission grating and produce a single parallelly aligned wavelengths output beam.
20. The method of claim 19 , wherein said plurality of beams is configured as one of a one-dimensional array or a two-dimensional array.
21. A monolithic transmitting spectral beam combiner (SBC), comprising:
a hollow structure having an input end and an output end;
a first transform optic (TO 1 ) fixedly attached to seal said input end;
a first transmission grating (TG 1 ) fixedly attached to seal said output end, wherein an internal area of said hollow structure is sealed, wherein said TG 1 comprises a first periodic structure located within said internal area;
a second transmission grating (TG 2 ) comprising a second periodic structure angularly facing said first periodic structure; and
a second transform optic (TO 2 ) between said TG 2 and said TO 1 .
22. The SBC of claim 21 , wherein said TG 1 and said TG 2 have opposite signs.
23. The SBC of claim 21 , wherein an input array of beams directed onto said TG 2 at a first angle −b relative to the TG 2 normal will exit said TG 2 at an angle +a relative to the TG 2 normal to produce an exit array of beams, wherein said TO 2 will direct said exit array to said TO 1 which will direct said exit array onto said TG 1 at an angle −a relative to the TG 1 normal, wherein said exit array will exit said TG 1 to produce an output array at an angle +b relative to the TG 1 normal, wherein the sum of the angles +a and −a equals zero and the sum of the angles +b and −b equals zero.
24. The SBC of claim 23 , wherein said input array of beams is configured in a one-dimensional array.
25. The SBC of claim 23 , wherein said input array of beams is configured in a two-dimensional array.
26. A method, comprising:
providing the apparatus of claim 23 ; and
directing an input array of beams onto said TG 2 at a first angle −b relative to the TG 2 normal.
27. The method of claim 26 , wherein said plurality of beams is configured in a one-dimensional array.
28. The method of claim 26 , wherein said plurality of beams is configured in a two-dimensional array.
29. The method of claim 26 , wherein said input array of beams comprises different wavelengths, wherein said input array of beams is directed onto said TG 2 so that they overlap on said TG 2 such that said output array is a single output beam.
30. The method of claim 26 , wherein said input array of beams comprises different wavelengths, wherein said input array of beams is directed onto said TG 2 so that they do not overlap on said TG 2 such that said output array is a single parallelly aligned wavelengths output beam.
31. The SBC of claim 21 , further comprising a third transform optic (TO 3 ), wherein said input array of beams is directed by said TO 3 onto said TG 2 at said first angle −b relative to the TG 2 normal.
32. The SBC of claim 21 , further comprising a fourth transform optic (TO 4 ), wherein said output array is a collimated output beam, wherein said TO 4 is positioned to focus said collimated output beam.
33. A transmitting spectral beam combiner (SBC), comprising:
a hollow structure having an input end and an output end;
a first transform optic fixedly attached to seal said input end; and
a first transmission grating fixedly attached to seal said output end,
wherein an internal area of said hollow structure is sealed, wherein said grating comprises a first periodic structure located within said internal area, wherein said first transmission grating is polarization insensitive for wavelengths from 1025 nm to 1085 nm with a theoretical transmitted diffraction efficiency >99%.
34. The SBC of claim 33 , wherein said first transmission grating has a period >900 nm and <1200 nm, a grating depth >1000 nm and <3000 nm and a grating duty cycle of >0.5 and <0.8.