Dual-output laser driving light source

Abstract

A dual output light source includes a laser driven light source that generates light from a thermal plasma in an emission angle range of at least 180 degrees. The first and second off-axis conical mirrors are located within at least 180 DEG emission of the thermal plasma such that light generated by the plasma and propagating from the first emission region is directed toward a first focal point of the first off-axis conical mirror and light generated by the plasma and propagating from the second emission region is directed toward a first focal point of the second off-axis conical mirror. The first and second off-axis conical mirrors reflect light in respective first and second optical paths. A first optical filter having a first bandwidth is located in the first optical path. A second optical filter having a second bandwidth is located in the second optical path.

Description

[0001] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described in this application in any way. Technical Field

[0002] The invention relates to a dual-output laser driven light source. Background Art

[0003] Many commercial and academic applications require broadband, high-brightness light with a spectral range of 170 nanometers to 2.1 microns. For example, broadband, high-brightness light is essential in many industrial applications, including lithography, metrology, accelerated life testing, development and testing of photoresists, defect detection, and microscopy. Other applications of broadband, high-brightness light include spectral analysis, spatial imaging, and blank mask detection. These and other applications require broadband, high-brightness light sources with high reliability, small size, low fixed cost, low operating cost, flexible adjustment to optimize for specific applications, and low structural complexity. Known broadband, high-brightness light sources are limited in performance and applicability due to various engineering difficulties. In addition, existing broadband, high-brightness light sources are typically single-output light sources with limited functionality. Summary of the Invention

[0004] The dual-output light source includes a laser-driven light source that generates light from a thermal plasma within an emission angle range of at least 180 degrees. The first and second off-axis conical mirrors are located within an emission angle of at least 180 degrees of the thermal plasma, such that light generated by the plasma and propagating from the first emission region is directed toward the first focus of the first off-axis conical mirror, and light generated by the plasma and propagating from the second emission region is directed toward the first focus of the second off-axis conical mirror. The first and second off-axis conical mirrors reflect light in their respective first and second optical paths. The first and second off-axis conical mirrors may include optical filters with different filtering functions. The first optical filter with the first filtering function is located in the first optical path, such that light with a first spectrum is transmitted to the first output end located at the second focus of the first off-axis conical mirror. Similarly, the second optical filter is located in the second optical path, such that light with a second spectrum is transmitted to the second output end located at the second focus of the second off-axis conical mirror.

[0005] A method for generating light according to the present teachings includes generating a thermal plasma that generates light over an emission angle range of at least 180 degrees. The generated light is propagated to a first focal point of a first mirror to cause the generated light to be reflected in a first optical path, and is propagated to a first focal point of a second mirror to cause the generated light to be reflected in a second optical path. The light in the first optical path is filtered to form a first output beam having a first spectrum. The light in the second optical path is filtered to form a second output beam having a second spectrum. The first output beam is propagated to a first output end at a second focal point of the first mirror. The second output beam is propagated to a second output end at a second focal point of the second mirror. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present teachings, and further advantages thereof, in conjunction with preferred and exemplary embodiments, will be described in greater detail in the following detailed description and in conjunction with the accompanying drawings. Those skilled in the art will appreciate that the drawings described below are for illustrative purposes only. These drawings are not necessarily drawn to scale; emphasis is generally placed on illustrating the principles of the present teachings. These drawings are not intended to limit the scope of applicants' teachings in any way.

[0007] Figure 1A Shown is a side view of an embodiment of a dual-output light source optical system configured in accordance with the present teachings, the system including a pair of off-axis conical mirrors that couple light flux from a plasma into two separate output channels.

[0008] Figure 1B Shown Figure 1A A top view of an embodiment of a dual-output light source optical system configured in accordance with the present teachings to include first and second off-axis conic mirrors for coupling light flux from a laser-driven light source into two separate output channels.

[0009] Figure 1C Shown Figure 1A A perspective view of an embodiment of a dual-output light source optical system configured in accordance with the present teachings to include first and second off-axis conic mirrors for coupling light flux from a laser-driven light source into two separate output channels.

[0010] Figure 2 Shown is a side view of an embodiment of a dual-output light source optical system configured in accordance with the present teachings, the system including a pair of off-axis conic mirrors that couple light flux from a plasma into two separate output channels that are combined into a single fiber channel.

[0011] Figure 3Shown is a side view of an embodiment of a dual-output light source optical system configured in accordance with the present teachings, the system including a pair of off-axis conic mirrors that couple light flux from a plasma into two separate output channels that are combined into a single free-space optical channel.

[0012] Figure 4 Shown are data showing the percent reflectivity of various reflective materials used in the reflective surfaces of the first and second off-axis conical mirrors in some embodiments of the dual-output light source optical systems of the present teachings as a function of wavelength in micrometers. DETAILED DESCRIPTION

[0013] The present teaching will now be described in more detail with reference to the exemplary embodiments shown in the accompanying drawings. Although the present teaching is described in conjunction with various embodiments and examples, the present teaching is not limited to these embodiments. On the contrary, the present teaching encompasses various alternatives, modifications, and equivalents understood by those skilled in the art. For those of ordinary skill in the art, based on an understanding of the present teaching, other implementations, modifications, and embodiments, as well as solutions applicable to other application fields, can also be identified, all of which fall within the scope of the present invention.

[0014] When the specification refers to "one embodiment" or "an embodiment", it means that the particular feature, structure, or characteristic being described is included in at least one embodiment of the present teachings. The phrase "in one embodiment" appearing in multiple places in the specification does not necessarily refer to the same embodiment.

[0015] It should be understood that the various steps in the method of this teaching can be performed in any order or simultaneously, as long as the operability of this teaching is not affected. In addition, it should be understood that the method and apparatus of this teaching can include any number or all of the described embodiments, as long as this teaching remains operable.

[0016] The present teachings relate to broadband light capable of operating at relatively high brightness. As used herein, the term "broadband" light refers to light having wavelengths within the spectral range of 170 nanometers to 2.1 microns. In other words, "broadband" light refers to light in the deep ultraviolet to infrared regions of the electromagnetic spectrum. Generating high-brightness light across such a broad electromagnetic spectrum presents considerable technical challenges. Generating light with different spectral characteristics at multiple output ports across such a broad electromagnetic spectrum is particularly challenging.

[0017] Broadband, high-brightness light sources are widely used in a variety of cutting-edge optical measurement and exposure applications. These broadband, high-brightness light sources are expected to be adaptable to a variety of usage scenarios, some of which require dual or multiple outputs providing light with varying optical properties. Currently, high-performance broadband, high-brightness light sources with such multiple outputs are not widely available on the market. It should be understood that much of the present teaching is described in conjunction with a dual-output light source. However, it should also be understood that the present teachings can be extended to light sources with three or more outputs, which are suitable for many applications requiring outputs with varying spectral properties and / or parallel operation.

[0018] Plasmas can be used to generate photons across a wide spectrum. For example, plasmas generated according to the present teachings can generate light from the deep ultraviolet spectrum to the infrared spectrum. The methods and apparatuses described herein are all related to plasma-generated light sources.

[0019] Figure 1A A side view of an embodiment of a dual-output light source system 100 configured in accordance with the present teachings is shown. In one embodiment, the light source system 100 includes a laser-driven light source 102 that generates broadband light from a hot plasma formed in the center of a bulb or cavity, the bulb or cavity having regions that are substantially transparent to electromagnetic radiation having a desired wavelength to allow light to pass through the cavity or bulb. In various embodiments, the laser-driven light source 102 includes a broadband light source that emits ultraviolet, visible, and / or near-infrared light.

[0020] Light is emitted in all directions from the plasma at the center of the bulb. The bulb or cavity is transparent to electromagnetic radiation of the desired wavelength over an emission angle of at least 180 degrees. For example, see U.S. Patent No. 11,587,781, entitled "Laser-Driven Light Source with Electrodeless Illumination," which is owned by the present applicant, as an example of an advanced laser-driven light source. Such electrodeless light sources can be provided by Energetiq, a Hamamatsu Group company located in Wilmington, Massachusetts. These light sources are based on Z-pinch plasmas, which completely avoid electrodes by inductively coupling current into the plasma. The plasma of such light sources is magnetically confined away from the light source walls, thereby reducing heat load, reducing debris and achieving excellent open-loop spatial stability and stable, repeatable power output. Such light sources are very attractive in applications that require high brightness and compact size.

[0021] The light source system 100 also includes first and second off-axis conical mirrors 104 and 104' that couple light flux from the plasma light source 102 into first and second separate optical output channels 106 and 106'. The first and second separate optical output channels 106 and 106' may be referred to as first and second optical paths 106 and 106'. In some embodiments of the present teachings, at least one of the first and second off-axis conical mirrors 104 and 104' is movable, such that the normal of the surface of the first off-axis conical mirror moves relative to the output aperture at the output end 116 and 116' of the light source. Furthermore, in one embodiment of the light source, at least one of the first and second off-axis conical mirrors 104 and 104' is an off-axis ellipsoidal mirror. In another embodiment of the light source, at least one of the first and second off-axis conical mirrors 104 and 104' is an off-axis parabolic mirror.

[0022] The first off-axis conical mirror 104 includes a reflective surface 108, which is located near the first emission area 110 of the laser-driven light source 102, so that light generated by the thermal plasma and propagating from the first emission area 110 of the laser-driven light source 102 is emitted to the first focus of the first off-axis conical mirror 104 and then reflected out in the first optical path 106, where the points represent ray tracing.

[0023] Similarly, the second off-axis conical mirror 104' includes a reflective surface 108', which is located near the second emission region 110' of the laser-driven light source 102, within an emission angle range of at least 180 degrees. Light from the second emission region 110' is reflected by the reflective surface 108' into the second optical path 106', where the dots represent ray tracing. The generated light propagating from the second emission region 110' of the laser-driven light source 102 is directed toward the first focus of the second off-axis conical mirror 104'. In many embodiments, the reflective surface comprises a material having a high reflectivity in the spectral region of interest. For example, a gold or aluminum coating may be used.

[0024] At least one of the reflective surface 108 on the first off-axis conical mirror 104 located near the first emission region 110 of the laser-driven light source 102 and the reflective surface 108' on the second off-axis conical mirror 104' located near the second emission region 110' includes an optical coating other than a reflective mirror coating. For example, at least one of these surfaces 108, 108' may include an optical coating that forms an optical filter. This type of optical filter may have the same filtering function for each surface 108, 108', or the optical filter may have an optical filtering function for one surface 108 and a different optical filtering function for the other surface 108'. The filtering function may be, for example, a bandpass filtering function, a high-pass filtering function, or a low-pass filtering function. In many embodiments of the light source 100 of the present teachings, a surface 108 on a first off-axis conical mirror 104 located near a first emission region 110 of the laser-driven light source 102 and a surface 108' on a second off-axis conical mirror 104' located near a second emission region 110' both include coatings that form optical filters, such that the first off-axis conical mirror 104 includes a filter having a first optical bandwidth and the second off-axis conical mirror 104' includes a filter having a second optical bandwidth, and the first and second optical bandwidths are not equal and do not have the same central wavelength.

[0025] For example, in one embodiment of the light source of the present teachings, the first off-axis conical mirror 104 includes an optical coating configured as an optical filter having a bandwidth in the ultraviolet region of the electromagnetic spectrum, and the second off-axis conical mirror 104' is configured as an optical coating having a bandwidth in the visible region of the electromagnetic spectrum. In another embodiment, the first off-axis conical mirror 104 includes an optical coating configured as an optical filter having a bandwidth in the ultraviolet region of the electromagnetic spectrum, and the second off-axis conical mirror 104' is configured as an optical coating having a bandwidth in the near-infrared region of the electromagnetic spectrum. In yet another embodiment, the first off-axis conical mirror 104 includes an optical coating configured as an optical filter having a bandwidth in the near-infrared region of the electromagnetic spectrum, and the second off-axis conical mirror 104' is configured as an optical coating having a bandwidth in the visible region of the electromagnetic spectrum. In another embodiment, the first off-axis conical mirror 104 and the second off-axis conical mirror 104' both include optical coatings configured as optical filters having the same bandwidth. In yet another specific embodiment, the first optical filter 114 and the second optical filter 114' are configured to filter substantially the same bandwidth in the electromagnetic spectrum.

[0026] A first optical filter 114 is positioned in the first optical path 106. The first optical filter 114 has a first filtering function, which allows light having a first spectrum to pass to a first output port 116 located at the second focus of the first off-axis conical mirror 104. Similarly, a second optical filter 114' is positioned in the second optical path 106'. The second optical filter 114' has a second filtering function, which allows light having a second spectrum to pass to a second output port 116' located at the second focus of the second off-axis conical mirror 104'. In one embodiment, the mechanical frame 112 supports the first and second optical filters 114, 114'. The first and second optical filters 114, 114' can be separate and independent filters, which can have filtering functions that are different from or the same as the filtering functions of any optical filters disposed on the first off-axis conical mirror 104 and the second off-axis conical mirror 104'.

[0027] The first and second optical outputs 116, 116' can be configured in a variety of ways suitable for a particular application of the dual-output light source 100. In some embodiments, the first optical output 116 has a first numerical aperture and the second optical output 116' has a second numerical aperture that is different from the first numerical aperture, thereby enabling the dual-output light source 100 to couple generated light into two different systems having different optical input configurations.

[0028] Furthermore, in various embodiments according to the present teachings, one or two optical fibers may be coupled to one or both of the first and second output ends 116, 116', so that the extreme ultraviolet (EUV) light generated by the light source system 100 is transmitted in one or two optical fibers, see for details. Figure 2 Possible configurations of outputs 116, 116' according to the teachings of the present invention may include any combination of free space and fiber optics.

[0029] Figure 1B Shown Figure 1A A top view of an embodiment of a dual output light source optical system 130 configured according to the present teachings to include first and second off-axis conical mirrors 104, 104' that couple the light flux from the laser driver light source 102 into two separate output channels 106, 106'. Figure 1AAs shown, the light source optical system 100 shows a mechanical frame 112 supporting first and second optical filters 114, 114'. First and second off-axis conic mirrors 104, 104' are located below the first and second optical filters 114, 114' in respective ones of the first and second optical paths 106, 106'. Reflective surfaces 108, 108' are shown directly below the first and second optical filters 114, 114'. A set of points in the centers of the first and second optical filters 114, 114' are generated by ray tracing and are located at respective second focal points 132, 132' of the first and second off-axis conic mirrors 104, 104'.

[0030] Figure 1C Shown Figure 1A A perspective view of an embodiment of a dual output light source optical system 160 configured in accordance with the present teachings to include first and second off-axis conic mirrors 104, 104' that couple light flux from a laser driven light source 102 into two separate output channels 106, 106'. Figure 1C The perspective view shown is the same as Figure 1A However, this perspective view shows the ray tracing in more detail, which depicts the first and second focal points of the first and second off-axis conic mirrors 104, 104'.

[0031] like Figure 1A As shown, the light source optical system 160 shows a mechanical frame 112 supporting first and second optical filters 114 and 114'. The laser driver light source 102 is positioned adjacent to first and second off-axis conical mirrors 104 and 104' to couple light flux from the plasma light source 102 into first and second optical output channels 106 and 106'. Ray trace points on the first and second off-axis conical mirrors 104 and 104' indicate where light strikes the first focal point of the conical mirrors 104 and 104' on the reflective surfaces 108 and 108'. Similarly, ray trace points on the first and second optical filters 114 and 114' indicate where light strikes the optical filters 114 and 114' as it travels toward the second focal points of the conical mirrors 104 and 104'. Output ports 116 and 116' show light striking the two second focal points 162 and 162' formed by the conical mirrors 104 and 104'.

[0032] Figure 2 A side view of an embodiment of a high brightness broadband dual output light source optical system 200 configured in accordance with the present teachings is shown, the system including a pair of off-axis conical mirrors 104, 104' that couple light flux from a plasma into two separate output channels 106, 106' that are combined into a single fiber channel. Figure 1A-C is similar to the dual-output broadband light source optical system 100, but further includes output fiber coupling and fiber combining, which combines light beams with different spectral characteristics.

[0033] More specifically, the light source system 200 includes first and second off-axis conical mirrors 104, 104' that couple light flux from the plasma light source 102 into first and second separate optical output channels 106, 106'. At least one of the first and second off-axis conical mirrors 104, 104' may be movable. At least one of the first and second off-axis conical mirrors 104, 104' may be an off-axis ellipsoidal mirror or an off-axis parabolic mirror. The first and second off-axis conical mirrors 104, 104' each include a reflective surface 108, 108' located adjacent to a respective one of the first and second emission regions 110, 110', which are within an emission angle range of at least 180 degrees, such that light generated by the hot plasma and propagating from these emission regions is directed toward a respective one of the first focal points of the first and second off-axis conical mirrors 104, 104' and then reflected out of a respective one of the first and second optical paths 106, 106'. Figures 1A-1C Similarly, the dots show the ray tracing of light after it reflects from the reflective surfaces 108, 108'.

[0034] At least one of the reflective surfaces 108, 108' on each of the first and second off-axis conical mirrors 104, 104' located near each of the first and second emission regions 110, 110' of the laser-driven light source 102 includes an optical coating that forms an optical filter. The filtering function of one or both of these optical filters can be, for example, a bandpass filtering function, a high-pass filtering function, or a low-pass filtering function. In many embodiments of the light source of the present teachings, both the surface on the first off-axis conical mirror 104 and the surface on the second off-axis conical mirror 104' include a coating that forms an optical filter, so that the first off-axis conical mirror 104 includes a filter having a first optical bandwidth, the second off-axis conical mirror 104' includes a filter having a second optical bandwidth, and the first and second optical bandwidths are unequal.

[0035] A first optical filter 114 that passes light having a first spectrum is located in the first optical path 106. Similarly, a second optical filter 114' that passes light having a second spectrum is located in the second optical path 106'. A mechanical frame 112 supports the first and second optical filters 114, 114'.

[0036] The first and second optical output ends 116, 116' are located at the second focal points of the first and second off-axis conical mirrors 104, 104', respectively. Figure 2In the fiber coupling configuration shown, first optical output 116 is coupled to first optical fiber 202 and second optical output 116' is coupled to second optical fiber 202'. Fiber combiner 204 includes a first input coupled to first optical fiber 202 and a second input coupled to second optical fiber 202'.

[0037] The output of the fiber combiner 204 passes a combined light beam that includes the spectra of the light beams in the first and second optical paths 106 and 106'. The combined spectrum includes the first light beam that has been filtered by any filter on the surface of the first off-axis conical mirror 104 and then filtered by the first optical filter 114. In addition, the combined spectrum includes the second light beam that has been filtered by any filter on the surface of the second off-axis conical mirror 104' and then filtered by the second optical filter 114'. In many embodiments, the filtering functions of the filters formed on the surfaces of the first and second off-axis conical mirrors 104 and 104' and / or the filtering functions of the first and second optical filters 114 and 114' are different, thereby combining two light beams with different spectra in the beam combiner 204 to produce a combined spectrum with a more complex spectrum for a specific application.

[0038] Figure 3 A side view of an embodiment of a dual output light source optical system 300 configured in accordance with the present teachings is shown, the system including a pair of off-axis conical mirrors 104, 104' that couple light flux from a plasma to two separate output channels 106, 106' that are combined into a single free-space optical channel. The dual output broadband light source optical system 300 is similar to Figure 2 The dual output broadband light source optical system 200 is shown, but includes a free space optical combiner 304, which generates a composite beam having different spectral characteristics. In addition, the different numerical apertures in the first and second output ports can pass beams with different beam shapes.

[0039] More specifically, as previously described, the light source system 300 includes first and second off-axis conical mirrors 104 and 104', which couple the light flux from the plasma light source 102 into first and second separate optical output channels 106 and 106'. Similar to the previous diagram, the dots illustrate ray tracing. The first and second off-axis conical mirrors 104 and 104', respectively, include reflective surfaces 108 and 108', located adjacent to respective first and second emission regions 110 and 110' of the laser driver light source 102. Surfaces 108 and 108' may include optical coatings that form optical filters. These optical filters may provide, for example, bandpass, high-pass, or low-pass filtering functions. In many embodiments of the present teachings, both a surface on the first off-axis conical mirror 104 and a surface on the second off-axis conical mirror 104' include coatings that form optical filters, such that the first off-axis conical mirror 104 includes a filter having a first optical bandwidth, the second off-axis conical mirror 104' includes a filter having a second optical bandwidth, and the first and second optical bandwidths are unequal.

[0040] As described in the previous figures, a first optical filter 114 that passes light having a first spectrum is located in the first optical path 106. Similarly, a second optical filter 114' that passes light having a second spectrum is located in the second optical path 106'. A mechanical frame 112 supports the first and second optical filters 114, 114'.

[0041] The first and second optical output ends 116, 116' are located at the second focal points of the first and second off-axis conical mirrors 104, 104', respectively. In some embodiments, the first optical output end 116 has a first numerical aperture, and the second optical output end 116' has a second numerical aperture different from the first numerical aperture. Figure 3 In the fiber coupling configuration shown, the first optical output 116 is coupled to a first optical fiber 302, and the second optical output 116' is coupled to a second optical fiber 302'. The first optical fiber 302 is coupled to a first input of an optical combiner 304, and the second optical fiber 302' is coupled to a second input of the optical combiner 304. In one embodiment, the optical combiner 304 may include a dichroic mirror.

[0042] The first light beam propagating from the first output end 116 with the first numerical aperture in the first optical fiber 302 is combined at the beam separation interface 306 of the optical combiner 304 with the second light beam propagating from the second output end 116 ′ with the second numerical aperture in the second optical fiber 302 ′. Figure 3A first light beam 308 and a second light beam 308' are shown having different beam characteristics associated with first and second numerical apertures. In various operating methods according to the present teachings, the first and second light beams 308, 308' have different spectral characteristics in addition to having different beam profiles.

[0043] Figure 4 The figure shows the percentage reflectivity data of the reflective materials of the reflective surfaces of the first and second off-axis conical mirrors 104, 104' as a function of wavelength in micrometers for various embodiments of the dual-output light source optical system of the present teaching. The specific choice of reflective material may depend on the specific application requirements, for example. The figure provides the percentage reflectivity data of five metal coatings (including UV enhanced aluminum, enhanced aluminum, protected aluminum, protected gold, and protected silver) at infrared to ultraviolet wavelengths. It should be understood that the embodiments of the dual-output broadband light source optical system taught by the present invention are not limited to Figure 4 Reflective material as described.

[0044] In operation, a method of generating light according to the present teachings includes generating a thermal plasma that emits light over an emission angle range of at least 180 degrees. The light can be generated over a broadband spectrum. The generated light is propagated to a first focus of a first off-axis conical mirror, where it is reflected in a first optical path. Some methods include moving the first off-axis conical mirror. In some methods, optical filtering can be performed while reflected in the first optical path. The light in the first optical path can be filtered to form a first output beam having a first spectrum. The first beam then propagates to an optical output end located at a second focus of the first off-axis conical mirror.

[0045] Similarly, the generated light is propagated to a first focal point of a second off-axis conical mirror, where it is reflected in a second optical path. Some methods include moving the second off-axis conical mirror. The light in the second optical path is filtered to form a second output beam having a second spectrum. In some methods, optical filtering may be performed during reflection in the second optical path. The second beam then propagates to a second optical output end located at a second focal point of the second off-axis conical mirror.

[0046] Some methods include coupling at least one of the first and second optical outputs to an optical fiber. Additionally, some methods include combining the first and second output beams into a combined beam that propagates in free space or in an optical fiber.

[0047] The methods of the present teachings can include performing a number of different types of optical filtering at the first and / or second off-axis conical mirrors and / or in the first and second optical paths to produce light having only desired spectral characteristics. For example, optical filtering can be performed so that only ultraviolet light is transmitted through the first output and only visible light is transmitted through the second output. Additionally, filtering can be performed so that only near-infrared light is transmitted through the first output and only ultraviolet light is transmitted through the second output. Additionally, filtering can be performed so that only visible light is transmitted through the first output and only near-infrared light is transmitted through the second output. In one approach, the filtering in the first and second optical paths is substantially identical.

[0048] Equivalent plan

[0049] Although the applicant's teachings are described in conjunction with various embodiments, this teaching is not intended to be limited to these embodiments. On the contrary, this teaching encompasses various alternatives, modifications, and equivalents that those skilled in the art will appreciate, and these changes can be made without departing from the spirit and scope of this teaching.

Claims

1. A dual-output light source comprising: a) a laser-driven light source that generates light from a hot plasma over an emission angle range of at least 180 degrees; b) a first off-axis conical mirror having a face with a first coating and positioned adjacent the hot plasma such that generated light propagating from a first region of the emission angle range of at least 180 degrees is directed toward a first focal point of the first off-axis conical mirror, the first off-axis conical mirror reflecting light in a first optical path; c) a second off-axis conical mirror having a face with a second coating and positioned adjacent the hot plasma such that light generated by the laser-driven light source and propagating from a second region of the emission angle range of at least 180 degrees is directed toward a first focal point of the face of the second off-axis conical mirror, the second off-axis conical mirror reflecting light in a second optical path; d) a first optical filter having a first bandwidth and an input located in the first optical path, light transmitted through an output of the first optical filter having a first spectrum; e) a first optical output end located at a second focus of the first off-axis conic mirror in the optical path of light transmitted through the output end of the first optical filter; f) a second optical filter having a second bandwidth and an input located in the second optical path, light transmitted through an output of the second optical filter having a second spectrum; as well as g) a second optical output located at a second focus of the second off-axis conic mirror in the optical path of light transmitted through the output of the second optical filter.

2. The light source according to claim 1, wherein At least one of the first and second off-axis conical mirrors comprises an off-axis ellipsoidal mirror.

3. The light source according to claim 1, wherein At least one of the first and second off-axis conical mirrors comprises an off-axis parabolic mirror.

4. The light source according to claim 1, wherein The laser-driven light source includes a broadband light source that emits ultraviolet light.

5. The light source according to claim 1, wherein The laser-driven light source includes a broadband light source that emits visible light.

6. The light source according to claim 1, wherein The laser-driven light source includes a broadband light source that emits near-infrared light.

7. The light source according to claim 1, wherein The optical fiber further comprises an end optically coupled to the first optical output end.

8. The light source according to claim 1, wherein The system further includes: a first optical fiber having one end optically coupled to the first optical output end; and a second optical fiber having one end optically coupled to the second optical output end.

9. The light source according to claim 1, wherein The first bandwidth comprises a bandwidth in the ultraviolet region of the electromagnetic spectrum and the second bandwidth comprises a bandwidth in the visible region of the electromagnetic spectrum.

10. The light source according to claim 1, wherein The first bandwidth comprises a bandwidth in the ultraviolet region of the electromagnetic spectrum and the second bandwidth comprises a bandwidth in the near infrared region of the electromagnetic spectrum.

11. The light source according to claim 1, wherein The first bandwidth comprises a bandwidth in the near infrared region of the electromagnetic spectrum, and the second bandwidth comprises a bandwidth in the visible region of the electromagnetic spectrum.

12. The light source of claim 1, wherein The first and second optical filters are configured to have the same bandwidth.

13. The light source of claim 1, wherein The first optical output end has a first numerical aperture, and the second optical output end has a second numerical aperture different from the first numerical aperture.

14. The light source of claim 1, wherein The invention further comprises an optical combiner having a first input end optically coupled to the first output end and a second input end optically coupled to the second output end, wherein an output end of the optical combiner provides a combined output light beam.

15. The light source of claim 14, wherein The optical combiner includes a fiber combiner.

16. The light source of claim 14, wherein The optical combiner includes a dichroic mirror.

17. The light source of claim 1, wherein The first coating layer includes a first filter, and the second coating layer includes a second filter, wherein a filtering function of the first filter is different from a filtering function of the second filter.

18. The light source of claim 1, wherein The first coating layer includes a first filter, the second coating layer includes a second filter, and the bandwidth of the first filter is the same as the bandwidth of the second filter.

19. The light source of claim 1, wherein The first coating layer is identical to the second coating layer.

20. The light source of claim 1, wherein At least one of the first and second off-axis conic mirrors includes a coating comprising gold.

21. The light source of claim 1, wherein At least one of the first and second off-axis conic mirrors includes a coating comprising aluminum.

22. The light source of claim 1, wherein The first off-axis conic mirror is movable such that a normal to a face of the first off-axis conic mirror moves relative to an output aperture of the light source.

23. The light source of claim 1, wherein The first off-axis conical mirror is movable so that the normal of the surface of the first off-axis conical mirror moves relative to the output hole of the light source, and the second off-axis conical mirror is movable so that the normal of the surface of the second off-axis conical mirror moves relative to the output hole of the light source.

24. A method of generating light, comprising: a) generating a thermal plasma that generates light over an emission angle range of at least 180 degrees; b) propagating the generated light to a first mirror, which reflects the generated light in a first optical path; c) filtering light in the first optical path to form a first output beam having a first spectrum; d) propagating the first output beam to a second focus of the first mirror; e) propagating the generated light to a second mirror, which reflects the generated light in a second optical path; f) filtering light in the second optical path to form a second output beam having a second spectrum; as well as g) Propagating the second output beam to a second focus of the second mirror.

25. The method of claim 24, wherein: Propagating the generated light to the first mirror includes propagating to a focal point of the first mirror.

26. The method of claim 24, wherein: Further comprising performing optical filtering at the first mirror.

27. The method of claim 24, wherein: Further comprising performing optical filtering at the first and second mirrors.

28. The method of claim 24, wherein: Further comprising combining the first and second output light beams.

29. The method of claim 24, wherein: Further comprising moving at least one of the first and second mirrors.

30. The method of claim 24, wherein: Generating the thermal plasma for generating light includes generating the light using a broadband light source.

31. The method of claim 24, wherein: Further comprising coupling at least one of the first output beams to an optical fiber.

32. The method of claim 24, wherein: Further comprising coupling the first output beam to an optical device having a first numerical aperture, and coupling the second output beam to an optical device having a second numerical aperture not equal to the first numerical aperture.

33. The method of claim 24, wherein: Further comprising coupling the first output beam to a first input of a beam splitter, and coupling the second output beam to a second input of the beam splitter.

34. The method of claim 24, wherein: The method further includes coupling the first and second output beams into a single optical fiber.

35. The method of claim 24, wherein: Filtering light in the first optical path to form a first output beam having a first spectrum includes filtering to transmit only ultraviolet light, and filtering light in the second optical path to form a second output beam having a second spectrum includes filtering to transmit only visible light.

36. The method of claim 24, wherein: Filtering light in the first optical path to form a first output beam having a first spectrum includes filtering to transmit only ultraviolet light, and filtering light in the second optical path to form a second output beam having a second spectrum includes filtering to transmit only near infrared light.

37. The method of claim 24, wherein: Filtering light in the first optical path to form a first output beam having a first spectrum includes filtering to transmit only visible light, and filtering light in the second optical path to form a second output beam having a second spectrum includes filtering to transmit only near infrared light.

38. The method of claim 24, wherein: The first spectrum and the second spectrum are the same spectrum.

39. The method of claim 24, wherein: The first spectrum is different from the second spectrum.

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