초록 ▼

The present invention is directed to guided wave systems, beam transport and waveguide techniques. The invention may comprise passive or active, hollow and dielectric core self-imaging mode wave guide systems, beam amplifiers (10, 40), laser resonators (70), beam transports, and waveguides. Embodime

The present invention is directed to guided wave systems, beam transport and waveguide techniques. The invention may comprise passive or active, hollow and dielectric core self-imaging mode wave guide systems, beam amplifiers (10, 40), laser resonators (70), beam transports, and waveguides. Embodiments may include rectangular cross-section waveguides, and preferably maintaining spatial profile of an input beam, such as a Gaussian beam, through the self-imaging period of the waveguide while unique new capabilities to mitigate non-linear distortions that corrupt spatial, spectral and temporal coherence and polarization. Additional aspects may include, for example, transport, amplification, phase/frequency control or modulation, deflection, conversion, synthetic aperture, distributed aperture, beam forming, beam steering, beam combining, power sampling, power combining and power splitting, among other features. Some embodiments may provide a self-imaging, multimode, waveguide (10) and self-imaging guided wave systems and beam transport. Embodiments of the present invention may further provide a method of self-imaging, multimode beam transport and other self-imaging wave guidance techniques.

대표청구항 ▼

1. An amplifier for a laser beam that has a wavelength (λ), comprising:a multi-mode, self-imaging waveguide having a core comprising a gain or mixing medium with an index of refraction (n) and a core length extending between a core entrance face and a core exit face, said core also having a rectangu

1. An amplifier for a laser beam that has a wavelength (λ), comprising:a multi-mode, self-imaging waveguide having a core comprising a gain or mixing medium with an index of refraction (n) and a core length extending between a core entrance face and a core exit face, said core also having a rectangular cross-section that provides a waveguide width (a), which is large enough to support and propagate multiple modes of the laser beam and a waveguide self-imaging period (WSIP) defined as a distance in the multi-mode waveguide in which a profile or image of the laser beam is periodically re-imaged, wherein WSIP=4na2/λ in general for the laser beam propagating through the core and WSIP=na2/λ when the laser beam is perfectly symmetric with respect to the center of the waveguide, and wherein said core is such that the laser beam propagating through the core from the core entrance fact to the core exit face has an optical path length with a numerical aperture and an exit face that is a non-zero integer multiple of the waveguide self-imaging period (WISP); a beam input coupling system capable of providing the profile or image of the laser beam with a TEM00 wavefront at the core entrance face within the numerical aperture of the core entrance face to propagate the laser beam into and through the waveguide to the exit face; and a pump light source coupled into the waveguide core medium to propagate pump light energy into the core medium to be extracted by the laser beam. 2. The amplifier of claim 1, including a reflector capable of reflecting the laser beam positioned to reflect the laser beam back through the waveguide core.3. The amplifier of claim 2, wherein the reflector is positioned at the exit face.4. The amplifier of claim 2, wherein the reflector is positioned outside the waveguide at a distance from the exit face.5. The amplifier of claim 4, wherein the reflector is shaped to re-focus the reflected laser beam onto the exit face for propagation back through the waveguide core.6. The amplifier of claim 4, including an optical imaging system between the exit face and the reflector that is capable of re-imaging the reflected laser beam on the exit face for propagation back through the waveguide core.7. The amplifier of claim 2, including an extraction optical coupling system capable of coupling the reflected laser beam out of the entrance face of the waveguide and separating the reflected laser beam from the pre-amplified laser beam.8. The amplifier of claim 7, wherein the extraction optical coupling system includes a polarizing beam splitter positioned in the pre-amplified beam and a ¼-λ birefringent retarder positioned between the polarizing beam splitter and the entrance face of the waveguide core.9. The amplifier of claim 2, wherein the pump light source is coupled into the waveguide core medium through the exit face.10. The amplifier of claim 9, wherein the reflector is transparent to the pump light.11. The amplifier of claim 1, wherein the pump light source is coupled into the waveguide core medium through a lateral side of the waveguide core medium.12. The amplifier of claim 11, wherein the pump light source is a laser diode.13. The amplifier of claim 12, wherein the pump light source produces pump light with a wavelength that is smaller than the wavelength λ of the laser beam.14. The amplifier of claim 11, including multiple pump light sources coupled into lateral sides of the waveguide core medium.15. The amplifier of claim 1, wherein the gain medium is a semiconductor material.16. The amplifier of claim 1, wherein the gain medium comprises a doped YAG.17. The amplifier of claim 16, wherein the gain medium comprises Yb:YAG.18. The amplifier of claim 16, wherein the semiconductor medium comprises Nd:YAG.19. The amplifier of claim 1, wherein the gain medium comprises Nd dopant.20. The amplifier of claim 1, wherein the gain medium comprises a liquid.21. The amplifier of claim 20, wherein the gain medium comprises CS2.22. The amplifier of claim 1, wherein the core is rectangular and is clad with a cladding material that has a lower index of refraction than the core.23. The amplifier of claim 1, wherein the core is rectangular, and has an index of refraction that is sufficiently greater than a surrounding atmosphere to confine the light beam in the core.24. The amplifier of claim 23, wherein the core comprises Nd-doped, phosphate glass.25. The amplifier of claim 22, including a heat sink positioned adjacent and in contact with the cladding material.26. The amplifier of claim 22, wherein the cladding material has at least one flat side and the heat sink is positioned in contact with the flat side.27. A laser resonator for producing a laser beam, comprising:a multi-mode, self-imaging waveguide positioned in an optical resonator cavity and having a core medium, which, when excited, emits light with a wavelength (λ), said core medium having a core length extending between a first core face and a second core face and also having an index of refraction (n) and a rectangular cross-section that provides a waveguide width (a), which is large enough to support and propagate multiple modes of a laser beam and a waveguide self-imaging period (WSIP) defined as a distance in the multi-mode waveguide in which a laser beam profile or image is periodically re-imaged, wherein WSIP=4na2/λ in general for the laser beam propagating through the core and WSIP=na2/λ when the laser beam is perfectly symmetric with respect to the center of the waveguide, and wherein said core length is such that the laser beam propagating through the core from the first face to the second face has an optical path length that is a non-zero integer multiple of the waveguide self-imaging period (WSIP), and wherein said optical resonator cavity includes a reflective surface in a configuration that reflects laser light that emanates from the core back into the core with a spatial mode profile that is substantially TEM00. 28. The laser resonator of claim 27, including a pump light source coupled optically to the waveguide core medium to propagate pump light energy into the core medium at a wavelength that optically excites the core medium to emit the λ wavelength light.29. The laser resonator of claim 27, wherein the core medium is a photovoltaic semiconductor material and the laser resonator includes electrical contacts positioned adjacent the core medium in a manner that facilitates application of an electric current to excite the semiconductor material to produce the laser light.30. The laser resonator of claim 27, wherein either the first core face or the second core face includes a rectangular aperture for the laser light to exit and enter the core medium, and wherein the optical resonator cavity includes the reflective surface positioned a distance apart from the core medium and in alignment with the rectangular aperture reflect laser light that emanates from the core medium back into the rectangular aperture with the substantially TEM00 spatial mode profile at the rectangular aperture.31. The laser resonator of claim 27, wherein the reflective surface is curved to focus the reflected laser light on the rectangular aperture with the substantially TEM00 spatial mode profile.32. The laser resonator of claim 30, including a pinhole aperture positioned between the reflective surface and the rectangular aperture so that laser light reflected by the reflective surface has to pass through the pinhole aperture to create the substantially TEM00 spatial mode profile in the reflected laser light.33. The laser resonator of claim 32, including a lens system positioned between the pinhole aperture and the rectangular aperture and configured to focus the substantially TEM00 spatial mode profile from the pinhole aperture onto the rectangular aperture.34. The laser resonator of claim 30, wherein the reflective surface is fully reflective.35. The laser resonator of claim 30, wherein the reflective surface is partially reflective.36. The laser resonator of claim 30, wherein the reflective surface is a first reflective surface and the optical resonator cavity includes a second reflective surface with the core medium positioned between the first reflective surface and the second reflective surface.37. The laser resonator of claim 36, wherein the second reflective surface is fully reflective.38. The laser resonator of claim 36, wherein the second reflective surface is partially reflective.39. The laser resonator of claim 36, wherein the second reflective surface is positioned at either the first core face or the second core face.40. The laser resonator of claim 27, wherein the self-imaging waveguide is rectangular in cross-section.41. The laser resonator of claim 40, wherein the rectangular waveguide comprises:a rectangular core medium with flat external surfaces; cladding on the external surfaces, said cladding also having at least one flat external surface; and a heat sink positioned in contact with the flat external surface of the cladding. 42. The laser resonator of claim 27, including cladding material with an index of refraction less than the core medium surrounding the core.43. The laser resonator of claim 42, wherein said cladding material is a first cladding material, and wherein the laser resonator includes:a second cladding material surrounding the first cladding material and having an index of refraction that is less than the first cladding material; and a pump light source coupled optically to the first cladding material.