Laser measurement device having removable and replaceable beam dump - Patents.com

Abstract

The present application discloses an apparatus configured to measure a property of a high power laser energy beam used in material processing. In one embodiment, the apparatus includes a housing having a first compartment and a second compartment separated from each other to prevent transfer of thermal energy therebetween. An optical module having an optical sensor configured to measure a property of the high power beam is disposed in the first compartment. An optical window capable of transmitting a substantial portion of the beam is disposed in an intermediate housing member separating the first and second compartments. A removable and replaceable beam dump configured to absorb a majority of the high power beam is disposed in the second compartment. The removable / replaceable beam dump allows operation of the apparatus without active cooling of the beam dump assembly, simplifying the apparatus and protecting the optical sensor in the first compartment.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. patent application Ser. No. 17 / 576,059, entitled "LASER MEASUREMENT APPARATUS HAVING REMOVABLE AND REPLACEABLE BEAM DUMP," filed Jan. 14, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] background High power lasers are used in a wide variety of applications, including material processing applications such as cutting, welding, stamping, and additive manufacturing. Accurate measurement of laser beam properties is important so that these processes can be controlled. Laser measurement instruments for this purpose include optical power meters, optical energy meters, and laser beam profilers. In some applications, significant attenuation of high power laser beams is required to avoid damage to these instruments. To avoid attenuation of the laser beam, a significant percentage of the beam power may be directed to a beam dump configured to absorb the portion of the beam that is not measured.

[0003] Although prior art beam dump systems have proven useful in the past, a number of drawbacks have been identified. In high power applications (e.g., 0.5 kW or greater), the beam dump can quickly become very hot. Excessive heat can affect the accuracy of laser measurement equipment. Solutions to this problem include liquid cooling using forced air convection or air-to-water heat exchangers. However, cooling systems can cause problems within the enclosed chamber or environment surrounding the high power laser processing system, including dust deposition on certain laser optics. For example, in some applications, forced air cooling systems can blow debris (e.g., dust or processing by-products) onto the beam delivery optics or damage electronic components. In other applications, liquid cooling or forced air convection systems are impractical or unavailable due to space constraints or lack of access to auxiliary equipment.

[0004] In view of the above, there continues to be a need for laser measurement instruments having beam dumps capable of handling high power laser beams without the need for forced air convection, liquid cooling, or other forms of active heat removal. Summary of the Invention

[0005] overview The present application discloses a laser measurement device and method configured to measure a plurality of properties of an incident laser energy beam. In one embodiment, the laser measurement device includes a housing having a housing body with an upper housing member, a middle housing member, and a housing base, the housing body having at least one first compartment and at least one second compartment formed therein. The second compartment is separated from the first compartment by a middle housing member, the middle housing member capable of reducing transfer of thermal energy between the second compartment and the first compartment. An aperture assembly is disposed on the upper housing member, the aperture assembly configured to pass the at least one incident laser energy beam to propagate into the first compartment. At least one first optical module is disposed on the first compartment, the first optical module having a first optical sensor configured to measure at least one first property of the laser energy beam. At least one optical window assembly is disposed on the middle housing member, and a fourth optical module is disposed on the first compartment. The fourth optical module has a fourth optical sensor configured to measure at least one second property of the laser energy beam. At least one beam dump receiver is formed in the at least one second compartment, the beam dump receiver configured to receive a beam dump assembly removably disposed therein, the beam dump assembly configured to absorb at least a portion of the laser energy beam. In one embodiment, the first optical sensor is a beam profiler and the fourth optical sensor is an optical power meter. Other optical sensors that may be used in the first compartment include an optical energy meter, a non-contact laser beam profiler using a camera, and a beam propagation analyzer. The beam properties measured include beam diameter, beam shape, beam parameter product, optical power, optical intensity, beam pulse power, beam pulse energy, beam waist, and beam radius.

[0006] In one embodiment, the incident laser energy beam is transmitted through an aperture assembly and propagates to a first optical module having at least one optical component configured to receive the laser energy beam from the aperture assembly, reflect a reflected first optical module signal to a first optical sensor, and pass at least one transmitted first optical module signal for propagation to a window assembly, the window assembly configured to receive a transmitted first optical module signal from the first optical module, reflect a reflected window optical signal to a fourth optical module, and pass at least one transmitted optical window signal for propagation into said at least one second section.

[0007] In one embodiment, the apparatus includes a second optical module located in the first compartment, the second optical module including at least one optical component configured to pass through and propagate a transmitted first optical module signal received from the first optical module. The second optical module may include an optical mount receiver configured to removably receive an optical mount having an optical component such that the optical component can be easily replaced.

[0008] In one embodiment, the device includes a first auxiliary module located within the first compartment, the first auxiliary module including a thermal sensor configured to sense a temperature of either an optical module located within or in thermal communication with the first compartment, the second compartment, or the housing body.

[0009] In other embodiments, the apparatus includes a second auxiliary module located in the second compartment, the second auxiliary module including a thermal sensor configured to sense a temperature of any device or light module located within or in thermal communication with the first compartment, the second compartment, or the housing body.

[0010] In one embodiment, the beam dump assembly includes a beam dump housing having a beam dump body with a recess formed therein, the recess configured to receive an absorber therein, the absorber in thermal communication with the beam dump body, and a temperature indicator in thermal communication with the beam dump body, the temperature indicator configured to indicate a temperature of the beam dump body.

[0011] In some embodiments, one or more heat dissipation features may be formed on the beam dump housing or body. Exemplary heat dissipation features include vents, fluid heat transfer systems, heat pumps, thermoelectric coolers, passive heat sinks, and forced convection heat sinks.

[0012] In another embodiment, a laser measurement device includes a method for measuring one or more properties of a laser energy beam, the method comprising: propagating the laser energy beam through an aperture optic to a first section of the laser measurement device; directing, with a first optical component, a reflected first optical module signal to a first optical module located within the first section, the first optical module configured to measure a first property of the reflected first optical module signal, the first property of the reflected first optical module signal representing a first property of the laser energy beam; reflecting the reflected window optical signal from an optical window to a fourth optical module located within the first section, the fourth optical module configured to measure a second property of the reflected window optical signal; the second property represents a second property of the at least one laser energy beam, passing the transmitted window optical signal through an optical window to propagate to a second section of the apparatus, the transmitted window optical signal incident on a first beam dump assembly, the first beam dump assembly being located within a beam dump receiver formed in the second section of the laser measurement apparatus, absorbing at least a portion of the transmitted window optical signal in the first beam dump assembly, monitoring a temperature of the at least one first beam dump assembly with at least one temperature indicator, and removing the first beam dump assembly and replacing the first beam dump assembly with a second beam dump assembly when the first beam dump assembly reaches a predetermined temperature. [Brief description of the drawings]

[0013] BRIEF DESCRIPTION OF THE DRAWINGS Various embodiments of a laser measurement device having a beam dump assembly are explained in more detail with reference to the accompanying drawings.

[0014] [Figure 1] FIG. 1 shows a cross-sectional view of a laser measurement device according to one embodiment.

[0015] [Diagram 2] FIG. 2 shows an exploded view of the laser measurement device shown in FIG.

[0016] [Diagram 3] FIG. 3 shows an exploded view of the beam dump assembly shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Detailed Description Hereinafter, examples of embodiments will be described with reference to the accompanying drawings. Unless explicitly stated, in the drawings, the sizes, positions, etc. of components, features, elements, etc. and the distances therebetween are not necessarily to scale and are exaggerated for ease of understanding. Like numbers refer to like elements throughout the drawings. Thus, the same or similar numbers may be described with reference to other drawings even if they are not mentioned or described in the corresponding drawings. Also, elements without reference numbers may be described with reference to other drawings.

[0018] The terms used in the specification are for the purpose of describing certain exemplary embodiments only and are not intended to be limiting. Unless otherwise defined, all terms (including technical and scientific terms) used in the specification have the same meaning as commonly understood by one of ordinary skill in the art. When used in the specification, the singular is intended to include the plural unless the content clearly indicates otherwise. Furthermore, it should be understood that the terms "comprises" and / or "comprising", when used in the specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise indicated, terms such as "first" and "second" are only used to distinguish elements from one another. For example, one fitting can be referred to as a "first fitting" and similarly another fitting can be referred to as a "second fitting" or vice versa.

[0019] Unless otherwise indicated, spatially relative terms such as "below," "lower," "lower side," "upper," and "opposite side" may be used herein for ease of description in describing the relationship of an element or feature to another element or feature as depicted in the figures. It should be understood that spatially relative terms are intended to include different orientations in addition to those depicted in the figures. For example, an element described as being "below" or "below" another element or feature would be oriented "above" the other element or feature if the object in the figure were inverted. Thus, the exemplary term "below" may include both an upward and downward orientation. If an object is oriented in another way (e.g., rotated 90 degrees or at another orientation), the spatially relative descriptors used herein may be interpreted accordingly.

[0020] Paragraph numbers used herein, unless specifically noted, are for organizational purposes only and should not be construed as limiting the subject matter described. It will be understood that many different forms, embodiments and combinations are possible without departing from the spirit and teachings of the present disclosure, and the present disclosure should not be construed as being limited to the example embodiments described herein. Rather, these examples and embodiments are provided so that this disclosure will be complete and all-inclusive, and will fully convey the scope of the disclosure to those skilled in the art.

[0021] Measuring high-power laser beams poses numerous challenges. High-power lasers are used in an increasing number of applications that require precise control of laser power and energy at the point where the laser beam interacts with the material being processed. In general, laser measurement instruments should ideally be insulated, as they can be susceptible to damage from high temperatures. While some beam dumps can be actively cooled (e.g., by liquid cooling, forced air convection cooling, or thermoelectric cooling), such cooling systems can be expensive and bulky, and can leak water or air into the laser processing equipment in which they are installed.

[0022] In the embodiments described below, an improved high power laser measurement apparatus is disclosed. Its advantages include a small footprint and volume, long exposure to high power lasers, and short or long exposure power measurements without active cooling (e.g., without fans or water tubes). Some applications require long exposure times for the measurement instruments. The apparatus protects the laser measurement instruments from contamination and damage from dust and debris from the surrounding environment by providing separate compartments for the laser measurement instruments and beam dumps. Also, by providing separate compartments for the instruments, large temperature changes of those instruments that may affect the accuracy of the measurement results are prevented, and the temperature within the compartments can be controlled using various methods and devices. The apparatus is modular and configurable, so it can be modified and optimized for different applications (e.g., by providing optics and measurement instruments optimized for each application). For example, if the processing laser is a continuous wave CO2 laser, the optical components in the apparatus can be made of zinc selenide or other materials designed for the mid-infrared (mid-IR) wavelength range of the CO2 laser, and their surface coatings can be tuned for operation at the wavelengths of the CO2 laser. In addition, the type of sensor (e.g., charge-coupled device (CCD), active pixel sensor (CMOS), etc.) used in these instruments can be selected for use at mid-IR wavelengths. Optical power sensors or power meters can be selected based on performance at a particular wavelength or wavelength range. For the beam dump itself, the absorber material and its coating can be selected for performance at mid-IR wavelengths. If it is necessary to use the laser measurement apparatus 100 in a laser processing system having a pulsed UV laser, the apparatus 100 can be reconfigured for use at UV wavelengths by replacing the optical components and measurement instruments optimized for use at UV wavelengths.

[0023] FIG. 1 illustrates a cross-sectional schematic diagram of an embodiment of a laser measurement apparatus 100 (also referred to herein as “apparatus 100”). In the illustrated embodiment, apparatus 100 includes a housing 200 having a beam dump assembly 700 disposed therein. Housing 200 includes a housing body 202 having an upper housing member 210, a first compartment 230, a middle housing member 240, and a housing base 280. A first compartment 230 and a second compartment 250 are formed within housing body 202, with second compartment 250 separated from first compartment 230 by middle housing member 240. In the illustrated embodiment, middle housing member 240 is configured to reduce transfer of thermal energy between second compartment 250 and first compartment 230, thereby preventing damage to measurement equipment within first compartment 230. A beam dump receiver 270 is formed in second compartment 250, configured to removably hold beam dump assembly 700 therein. In the second section 250 , a beam dump assembly 700 is supported by the housing base 280 .

[0024] In the illustrated embodiment, an aperture assembly 220 is disposed within the upper housing member 210. The aperture assembly 220 includes an aperture optic 224 configured to allow the incident laser energy beam 10 to propagate therethrough into the first compartment 230. In the illustrated embodiment, the mid-housing member 240 is configured to receive at least one optical window assembly 760 therein. In the illustrated embodiment, the optical window assembly 760 includes a housing configured to receive and hold at least one optical component 762 therein. In this embodiment, the optical window assembly 760 is configured to be removed from the mid-housing member 240 to replace the optical component 762 due to damage, contamination, or for reconfiguration of the device 100. In the illustrated embodiment, the optical component 762 is an optical window, although one skilled in the art would understand that the optical component 762 may be any type of optical component.

[0025] Overall, the apparatus 100 described in the following embodiments is configured to separate an incident laser energy beam 10 into multiple optical signals that are in turn measured by various optical sensors included in various optical modules. The apparatus 100 is designed and configured such that each of the optical signals measured by the optical sensors is representative of one or more properties and characteristics of the incident laser energy beam 10. Thus, even though each optical sensor measures a different portion of the incident laser energy beam 10, the measurements can be used by an operator to understand the properties and characteristics of the incident laser energy beam 10. Any number of optical modules may be located in the first section 230. In the illustrated embodiment, the equipment located in the first section 230 includes a first optical module 500, a second optical module 300, a third optical module 400, and a fourth optical module 600. In the illustrated embodiment, the first optical module 500 includes an optical component 502 configured to reflect (or otherwise direct) a reflected first optical module signal 504 to an optical sensor 510 and pass a transmitted first optical module signal 508. The reflected first optical module signal 504 is representative of the incident laser energy beam 10, such that the properties or characteristics of the reflected first optical module signal 504 measured by the optical sensor 510 are representative of the properties or characteristics of the incident laser energy beam 10. The transmitted first optical module signal 508 is incident on the second optical module 300, which is configured to pass the transmitted first optical module signal 508 for propagation to the optical window assembly 760. The optical window assembly 760 is configured to receive the transmitted first optical module signal 508 from the second optical module 300, pass the transmitted window optical signal 764 for propagation into the second section 250, and reflect the reflected window optical signal 766 to the fourth optical module 600. The reflected window optical signal 766 is also representative of the incident laser energy beam 10, such that the properties or characteristics of the reflected window optical signal 766 measured by the optical sensor 610 are also representative of the incident laser energy beam 10. Depending on the configuration required for a particular laser processing application, any one of the optical modules may be optional.

[0026] In one embodiment, the fourth optical module 600 is provided as an optical power meter having a fourth optical sensor 610 as an optical detector configured to measure a percentage of the optical power of the incident laser energy beam 10 and transmit measurement data representative of the optical power to the controller 1000. In this embodiment, the optical window assembly 760 includes a beam splitter configured to reflect a portion of the transmitted first optical module signal 508 to the optical power meter 600 as a reflected window optical signal 766 and pass the remaining portion as a transmitted window optical signal 764. The proportion of the transmitted window optical signal 764 to the reflected window optical signal 766 can be selected by coating a surface of the optical component 762. For example, in the illustrated embodiment, in one aspect, the optical component 762 is left uncoated, resulting in approximately 4-5% (depending on the incidence / reflection angles, optical materials, and laser wavelength) of the transmitted first optical module signal 508 being reflected to the optical power meter 600 as the reflected window optical signal 766. The opposite surface is coated with an anti-reflective coating configured to allow a majority of the transmitted first optical module signal 508 to propagate to the second section 250 without being reflected by the uncoated surface. One skilled in the art will appreciate that the coating on the optical component 762 may be configured to reflect any percentage of the transmitted first optical module signal 508 to the optical power meter 600 as a reflected window optical signal 766. If the fourth optical sensor 610 is provided as an optical power meter thermal disk, such that a small percentage of the incident laser energy beam 10 reaches the optical power meter 600, the power meter may be provided with a fast response time (e.g., less than about 5 seconds). In some cases, measuring high power laser beams requires a detector capable of handling these high power levels (e.g., a thermal air-cooled or water-cooled power meter), but these detectors often have a large footprint and slow response times (e.g., about 30 seconds).

[0027] In the illustrated embodiment, the second optical module 300 includes an optical component 302 that is selected to reduce the laser fluence or optical power density (i.e., laser energy per unit area) that reaches the optical window assembly 760 and the beam dump assembly 700, thereby avoiding damage to the optical window assembly 760 and the beam dump assembly 700. In addition, the absorption of the optical energy by the beam dump assembly 700 may be optimized by spreading the optical energy incident on the beam dump assembly 700 over a larger area. For example, the optical component 302 may be provided as a short focal length (e.g., 20 mm) lens such that the focal point (not shown) of the transmitted first optical module signal 508 is located in the area between the optical component 302 and the optical window assembly 760, such that the beam is expanded as it enters the optical window assembly 760. The optical components 302 may be arranged in any manner desired or useful, including using different lenses with different focal lengths (e.g., for different input beam divergences, powers, and beam qualities) and different lenses with coatings selected for different wavelengths or power densities (e.g., narrow wavelength range coatings that are thin and more durable for high power densities). In the illustrated embodiment, the optical components 302 are held in optical mounts 304 that are configured to allow a system operator to remove and replace the optical components 302 due to optical damage or reconfigure the system to change the operating wavelength, beam divergence, or other optical properties of the optical components 302.

[0028] The optical modules used in the apparatus 100 may include any of a variety of optical instruments, including, but not limited to, a camera-based laser beam profiler, a non-contact beam profiler, a beam propagation analyzer, a scanning slit beam profiler, a pyroelectric array sensor, a beam diagnostic camera, a laser beam attenuator, an optical power sensor (e.g., optical power meter, optical energy meter, photodetector, thermopile, etc.). For example, the optical sensor 510 in the first optical module 500 may be configured (or reconfigured) with any of these instruments depending on the type of processing laser being used (e.g., operating at different wavelengths, pulse repetition rates, or optical powers). In one embodiment, the optical sensor 510 may measure, but not be limited to, the beam diameter (e.g., FWHM, 1 / e 2 ), beam waist, beam radius, beam shape, beam parameter product (M 2 The optical module may include a laser beam profiling camera configured to measure a number of beam properties including, but not limited to, a power factor, a beam power, a beam energy, a pulse power, a pulse energy, a light intensity, a laser fluence (light energy per unit area), and the like, or any combination thereof. In one embodiment, the optical sensor 510 may be provided as a BEAMWATCH® non-contact beam profiling system or a BEAMSQUARED® laser beam propagation analyzer system, both sold by Ophir Optronics Solutions. In another embodiment, the optical sensor 510 may be provided as a pyroelectric array camera, such as the PyroCam™ 4 sold by Ophir Optronics Solutions. In some embodiments, the optical module may include only optical components, including but not limited to, lenses, filters, mirrors, beam splitters, optical wedges, optical attenuators, and the like, or any combination thereof. One skilled in the art will appreciate that any of a variety of optical components may be used in the optical modules described herein.

[0029] In the illustrated embodiment, the third optical module 400 includes an optical component 402 configured to direct the third optical module signal 404 to the optical device 410. In one embodiment, the third optical module signal 404 is a portion of the reflected first optical module signal 504 that is directed away from the first optical module 500 to prevent saturation or damage of the first optical module 500 (e.g., when the optical sensor 510 in the first optical module 500 is configured as a beam profiling camera). In this embodiment, the optical device 410 is configured as a low power beam dump configured to absorb the third optical module signal 404. In this embodiment, the optical component 402 is configured as a beam splitter, optical wedge, or leaky mirror configured to direct, deflect, or reflect a portion of the reflected first optical module signal 504 to the beam dump 410. For example, if the reflected first optical module signal 504 does not require attenuation before reaching the optical sensor 510, the third optical module 400 may not be used.

[0030] In one embodiment, the first optical module 500 also includes an optical component 506 configured to condition the reflected first optical module signal 504 and pass the modified reflected first optical module signal 504' to propagate to the optical sensor 510. For example, the optical component 506 may be provided as a neutral density filter configured to reduce light transmission evenly across a portion of a particular wavelength spectrum. If provided as such, the neutral density filter 506 may be selected to increase the dynamic range of the optical sensor 510. One skilled in the art will appreciate that the optical component 506 may be provided as any of a filter, lens, mirror, and the like, or any combination thereof. The first optical module 500 may also be configured to facilitate replacement of the optical component 506 if it is damaged or if the first optical module 500 is reconfigured as described above. In one embodiment, the first optical module 500 and / or the optical sensor 510 are fixed relative to other components or modules within the housing body 202. In other embodiments, the first light module 500 and / or the light sensor 510 are movable relative to other components or modules within the primary housing 202 .

[0031] In some embodiments, the apparatus 100 may include one or more auxiliary modules 1100 located in the first compartment 230. A variety of devices may be used as the auxiliary module 1100. In one embodiment, the auxiliary module 1100 includes a thermal sensor 1110 configured to sense the temperature of any one of the surrounding environment in the first compartment 230, the light module (e.g., the light sensor 510), or any other device or component located in or in thermal communication with the first compartment 230, and transmit measurement data representative of the temperature to the controller 1000. In this embodiment, based on the measurement data, the controller 1000 may alert an operator if the temperature of any component in the first compartment 230 rises above a threshold level that may cause damage to the light module located in the first compartment 230. In other embodiments, the auxiliary module 1100 may be provided as an active cooling system capable of sensing and controlling the temperature of the surrounding environment in the first compartment 230, the optical module, or other devices or components located in or in thermal communication with the first compartment 230. Such active cooling systems may include a temperature sensor (not shown) configured to transmit measurement data to a controller such that the active cooling system can be operated in a closed loop. In other embodiments, the auxiliary module 1100 may be provided as a filtration system capable of removing dust or debris from the first compartment 230, thereby preventing such dust or debris from accumulating on surfaces of optical elements or other components of the optical module located in the first compartment 230. In yet other embodiments, the auxiliary module 1100 may be provided as a dehumidifier or getter configured to remove gases or vapors from the first compartment 230.In yet other embodiments, the auxiliary module 1100 may be provided as a purge gas source or inlet configured to supply or introduce various purge gases (e.g., argon, helium, nitrogen, clean dry air) into the first compartment 230 (e.g., to prevent or control oxidation of internal components or to prevent particulate buildup on any optical surfaces). Those skilled in the art will appreciate that the auxiliary module 1100 may be provided as any device or subsystem required or beneficial to optimize the performance of the apparatus 100 or to enhance the safety of the apparatus or its operator.

[0032] In some embodiments, the apparatus 100 may include one or more auxiliary modules 1200 located in the second compartment 250. In the illustrated embodiment, the auxiliary module 1200 includes a thermal sensor 1210 configured to sense any one of the temperatures of the housing body 202, the ambient environment in the second compartment 250, or any optical modules or other devices located in or in thermal communication with the second compartment 250, and transmit measurement data representative of the temperatures to the controller 1000. In this embodiment, the controller 1000 may alert an operator if the temperature of the beam dump assembly 700 rises above a threshold level that would indicate that the beam dump assembly 700 should be replaced, for example if the temperature indicator 730 (described below) is not functioning properly. In other embodiments, the auxiliary module 1200 may be provided as an interlock system (not shown) capable of shutting down the processing laser if the beam dump assembly 700 is removed while the processing laser is operating. Such an interlock system may include one or more proximity sensors (not shown) configured to detect the presence of beam dump assembly 700 within beam dump receiver 270. Those skilled in the art will appreciate that auxiliary module 1200 may be provided as any device or subsystem required or beneficial to optimize the performance of apparatus 100 or to enhance the safety of the apparatus or its operator.

[0033] In the illustrated embodiment, an interface connector 1010 is provided in electrical communication with the optical modules 400, 500, 600 and the auxiliary modules 1100, 1200 to control their operation and receive data from them. The interface connector 1010 can be configured to transmit signals from any of the optical modules and / or auxiliary modules to the controller 1000 via a communication path 1012. In the illustrated embodiment, the connector 1010 is a USB connector, although a variety of connectors may be used. If desired, the optical modules and auxiliary modules may be in wireless communication with the controller. In some embodiments, the device 100 may include multiple interface connectors or controllers. In other embodiments, the controller 1000 may be located within the housing body 202.

[0034] FIG. 2 shows an exploded view of the device 100. In the illustrated embodiment, the upper housing member 210 includes an aperture receiver 222 formed therein that is configured to receive and hold the aperture assembly 220 therein. The first optical module 500 is mounted to the aperture assembly 220, which allows for easy access for replacement, inspection, or reconfiguration of the first optical module 500. Those skilled in the art will appreciate that the first optical module 500 may be mounted in the housing body 202, the upper housing member 210, or anywhere in the first compartment 230. During inspection or reconfiguration of the device 100, the aperture assembly 220 can be removed from the aperture receiver 222 and replaced with a new aperture optic 224. If desired, the upper housing member 210 may include multiple aperture receivers configured to receive various apertures or aperture assemblies.

[0035] In the illustrated embodiment, the housing body 202 is formed with at least one air transfer feature or vent 290 configured to allow thermal energy to pass therethrough. In this embodiment, the vent is positioned in fluid communication with the second compartment 250 to allow thermal energy to flow from the beam dump assembly 700 to the surrounding environment. One or more fluid forcing devices or fans (not shown) may be provided that are configured to generate a flow of fluid (e.g., air or other gas) to conduct the thermal energy away from the beam dump assembly 700.

[0036] In the illustrated embodiment, the second optical module 300 includes an optical mount 304 configured to hold the optical component 302 therein. An optical mount receiver 306 configured to removably hold the second optical module 300 therein is formed in the housing body 202. As such, the second optical module 300 can be removed from the housing body 202 to allow replacement of the optical component 302 (e.g., during reconfiguration of the device 100). In this embodiment, the housing base 280 includes one or more guide members 282 configured to guide the beam dump assembly 700 when the beam dump assembly 700 is placed in the beam dump receiver 270. In this embodiment, the fourth optical module 600 is mounted to the upper housing member 210 such that the fourth optical module 600 can be replaced or reconfigured by removing the upper housing member 210. In other embodiments, the fourth optical module 600 can be accessed for removal via the aperture receiver 222, thereby eliminating the need to remove the upper housing member 210. In some embodiments, the optical mount 304 may house multiple optical components mounted therein.

[0037] In the illustrated embodiment, the beam dump assembly 700 includes a beam dump housing 710 having a beam dump body 712 configured to absorb the transmitted window light signal 764. The beam dump assembly 700 includes an indicator, such as a temperature indicator 730 configured to sense a temperature of the beam dump body 712. One or more locking members or pins 750 may be provided that are configured to traverse one or more locking passages (not shown) formed in the housing body 202 and engage with corresponding locking pin receivers 752 formed in the beam dump housing 710 or the beam dump body 712 to securely hold the beam dump assembly 700 within the beam dump receiver 270. If desired, the locking pins 750 may engage one or more other locking passages, devices, or features (not shown) located in or formed in the second section 250 or the beam dump receiver 270.

[0038] FIG. 3 shows an exploded view of the beam dump assembly 700. As mentioned above, in the illustrated embodiment, the beam dump assembly 700 includes a beam dump housing 710 and a beam dump body 712. The beam dump body 712 may be contained within the beam dump housing 710, or the beam dump body 712 may function as the beam dump housing 710 (or conversely, the beam dump housing 710 may function as the beam dump body 712). Thus, for purposes of this disclosure, mechanical features formed within or components attached to the beam dump housing 710 may also be considered to be formed on or attached to the beam dump body 712. The beam dump body 712 includes at least one recess 714 formed therein and configured to receive at least one absorber 800 held therein. In the illustrated embodiment, the beam dump body 712 acts as the primary heat sink for the beam dump assembly 700. Thus, the beam dump body 712 may be formed from any material having a high heat capacity and / or high thermal conductivity properties. Exemplary materials for the beam dump body 712 include, but are not limited to, aluminum, copper, copper tungsten, tungsten carbide, steel, and various ceramic or composite materials. In one embodiment, the beam dump body 712 may be formed from a material configured to store thermal energy via a phase change mechanism, such as a salt configured to change from a solid state to a liquid state upon absorbing thermal energy. In other embodiments, the beam dump assembly 700 may include multiple beam dump bodies. In yet other embodiments, multiple recesses may be formed in the beam dump body 712. In other embodiments, the beam dump body 712 may be formed from a material having a medium to low heat capacity and / or medium to low thermal conductivity properties.

[0039] In the illustrated embodiment, the beam dump housing 710 includes a front plate 720 that is attached to the beam dump housing 710 or the beam dump body 712 by one or more fasteners 722. One or more handles or gripping members (not shown) may be attached to the front plate 720 to facilitate removal of the beam dump assembly 700 from the beam dump receiver 720. In the illustrated embodiment, the front plate 720 further includes a temperature indicator 730 configured to alert a system operator that the beam dump assembly 700 has reached a specified temperature and should be removed from the beam dump receiver 270. In one embodiment, the temperature indicator 730 is provided as a color changing temperature indicator that changes to a bright color when the beam dump body 712 reaches a predetermined temperature. In other embodiments, the temperature indicator 730 is configured to provide a different indication or warning that a threshold temperature has been reached (e.g., by flashing or sending a signal to the controller 1000). In other embodiments, the temperature indicator 730 may include a display configured to display the temperature of the beam dump body 712 (e.g., in degrees Fahrenheit or Celsius). In other embodiments, the beam dump housing 710 may not include a front plate and the temperature indicator 730 may be located within the beam dump housing 710 or the beam dump body 712. One skilled in the art will appreciate that the temperature indicator 730 may be provided as a variety of temperature indicators. In other embodiments, the indicator 730 may display various performance information about the beam dump assembly 700, such as the number of operational hours the beam dump assembly 700 has been in use. One skilled in the art will appreciate that the indicator 730 may be used to communicate various information to a user or operator of the apparatus 100.

[0040] In the illustrated embodiment, one or more rollers or similar devices or features 740 are mounted and held by corresponding connecting members or fasteners 742 to the bottom edge of the beam dump housing 710 or beam dump body 712. In this embodiment, the rollers 740 are configured to roll along the housing base 280 or allow movement of the beam dump body relative to the housing base 280 between the guide members 282 of the housing base 280 (shown in FIG. 2 ) to facilitate removal of the beam dump assembly 700, to allow consistent positioning of the beam dump assembly 700 within the beam dump receiver 270, or to ensure that the absorber 800 is in a consistent position relative to the transmission window optical signal 764 during operation. In the illustrated embodiment, the rollers are formed from Teflon. In other embodiments, the rollers 740 can be formed from other polymers designed for high temperature operation, such as polyetheretherketone (PEEK). One skilled in the art would understand that the rollers 740 can be formed from a variety of materials. In other embodiments, rollers 740 may not be used and the beam dump assembly 700 may slide along the top surface of the housing base 280 .

[0041] In the illustrated embodiment, the absorber 800 includes an absorber body 802 having a convex region 804 and a concave region 806 formed thereon. A coating 808 may be applied to the concave region 806 of the absorber body 802, the coating 808 being adapted to control or optimize absorption of incident optical radiation. In one embodiment, the coating 808 may be adapted to protect the absorber body 802 from being damaged by the transmitted window optical signal 764 described above. One or more surface features (not shown) configured to enhance absorption of the transmitted window optical signal 764 may be formed on the concave region 806 of the absorber body 802 and covered by the coating 808. In some cases, the concave region 806 may not include a coating or surface feature. In the illustrated embodiment, a heat transfer member 716 is disposed between the absorber body 802 and the beam dump body 712 to facilitate transfer of thermal energy from the absorber 800 to the beam dump body 712. In the illustrated embodiment, the heat transfer member 716 is provided as a solid disk of material. In some cases, the heat transfer member 716 may be provided as a tubular disk or washer. A number of fasteners 810 are provided to hold the absorber body 802 firmly in thermal communication with the heat transfer member 716 and the beam dump body 712. The heat transfer member 716 and the absorber body 802 may be formed from any material having high heat capacity and / or high thermal conductivity properties. Exemplary materials for the heat transfer member 716 and the absorber body 802 include, but are not limited to, aluminum, copper, brass, bronze, copper tungsten, tungsten carbide, steel, metal alloys, or various ceramic or composite materials. One skilled in the art will appreciate that the heat transfer member 716 may be formed from various materials. In some embodiments, the heat transfer member 716 may not be used, and instead, the absorber body 802 may be placed in direct thermal contact with the beam dump body 712.

[0042] As mentioned above, one advantage of the beam dump assembly 700 is that it can absorb and store a significant amount of thermal energy without the use of an active cooling system. However, in certain embodiments, the beam dump body 712 can include one or more cooling systems or features configured to transfer thermal energy away from the beam dump body 712. In one embodiment, a cooling system 900 can be provided that includes an inlet fitting 910 in fluid communication with one or more cooling channels (not shown) formed in the beam dump body 712. A cooling fluid (e.g., air, inert gas, water, ethylene glycol, etc.) can enter the beam dump body 712 via the inlet fitting 910 and exit the outlet fitting 912. In some cases, no cooling fluid can be used. In other embodiments, one or more thermoelectric coolers (not shown) can be provided that are configured to transfer heat away from the beam dump body 712. In other embodiments, one or more heat pumps can be provided that can remove heat from the beam dump body 712. In other embodiments, forced air convection may be used to remove heat from the beam dump body 712 through the vents 290. Such a forced air convection system may include an air flow source (e.g., a fan) capable of providing air flow through one or more heat sinks or cooling fins (not shown) formed on or in thermal communication with the beam dump body 712.

[0043] During use of the apparatus 100, when the temperature of the beam dump body 712 reaches a threshold level (e.g., as indicated by the temperature indicator 730), an operator of the apparatus 100 may remove the locking pin 750, manually remove the beam dump assembly 700 from the beam dump receiver 270, and replace the beam dump assembly 700 with a cold beam dump assembly 700. The hot beam dump assembly 700 may be cooled in a variety of ways (e.g., by immersion in water, by placing in a cooled space, or by allowing heat to radiate to the surrounding environment). In some cases, the beam dump assembly 700 may be removed and replaced using an automated process (e.g., by a robot).

[0044] When the apparatus 100 is provided as described in any of the above embodiments, the apparatus 100 may be configured for various modes of operation. In one exemplary mode of operation, referring to Figures 1 and 2, the apparatus 100 is configured to measure properties of an incident laser energy beam 10 having a wavelength of 1064 nanometers and a maximum optical power of about 1 kW propagating through the aperture optic 224. In this mode of operation, the first optical module 500 includes a beam profiler using a camera as the optical sensor 510, and the fourth optical module 600 includes an optical power meter as the fourth optical sensor 610. In this mode of operation, the optical component 502 of the first optical module 500 is provided as an optical wedge beam splitter having an optical surface with an anti-reflective coating configured to reflect about 0.5% of the incident laser energy beam 10 and transmit about 99.5% of the incident laser energy beam. The opposite optical surface of the optical wedge is oriented at an angle (e.g., about 7°) relative to the first optical surface. Configured in this manner, reflections from the optical surfaces on the opposite side of the optical wedge 502 are not directed towards the beam profiler 510 .

[0045] In this mode of operation, with the optical components arranged as described above, the laser energy beam 10 is incident on the optical component 502 of the first optical module 500, which reflects a reflected first optical module signal 504 having a power of approximately 5 W and transmits a transmitted first optical module signal 508 having a power of approximately 995 W. The reflected first optical module signal 504 is incident on the third optical module 400, which is arranged as an auxiliary beam dump 410 with the optical component 402 arranged as an optical wedge configured to propagate approximately 99.8% of the light incident thereon and direct it to the auxiliary beam dump 410, and to reflect (or transmit or direct) approximately 0.02% of the light incident thereon towards the beam profiler 510. Thus, optical component 402 directs third optical module signal 404 having a power of approximately 4.995 W to auxiliary beam dump 410, which passes approximately 0.005 W to optical component 506, which passes modified reflected first optical module signal 504' to optical sensor 510. During this mode of operation, an operator can monitor the optical power measured by optical power meter 610 and the beam profile measured by beam profiler 510 to ensure that these beam properties are within the desired operating parameters or tolerances for the process being performed by the laser processing system.

[0046] In this mode of operation, the optical component 302 of the second optical module 300 is provided as a bi-convex lens with a focal length of about 20 mm and anti-reflection coatings on both sides, allowing almost all of the light incident thereon to propagate through. As discussed above with respect to FIG. 1, one surface of the optical component 762 is left uncoated, allowing approximately 4-5% (depending on the angle of incidence or reflection, optical material, and laser wavelength) of the transmitted first optical module signal 508 to be reflected as a reflected window optical signal 766 to the optical power meter 610 of the fourth optical module 600. The optical component 762 passes the transmitted window optical signal 764 through to the beam dump assembly 700 where it is absorbed by the absorber 800 and converted to thermal energy that is stored in the beam dump body 712. In this exemplary mode of operation, after approximately two minutes of operation, the beam dump body 712 reaches a predetermined temperature (e.g., through a system setting in the apparatus 100) of approximately 50° C., and the temperature indicator 730 indicates to the operator that the beam dump assembly 700 should be replaced, so the operator shuts down the processing laser and removes the hot beam dump assembly 700 (i.e., the “first” beam dump assembly) from the beam dump receiver 270 and replaces it with a cold beam dump assembly 700 (i.e., the “second” beam dump assembly). The hot beam dump assembly 700 is then allowed to cool so that it is again usable.

[0047] In another exemplary mode of operation, the apparatus 100 is configured to measure properties of an incident laser energy beam 10 having a wavelength of 532 nanometers and a maximum optical power of about 500 W incident on the aperture optic 224. The optical sensor 510 is provided as a beam profiler and the optical sensor 610 is provided as an optical power meter. In this mode of operation, the apparatus 100 may use the same optics and sensors as used in the previously described mode of operation (wherein the laser energy beam has a wavelength of 1064 nanometers). In some cases, the apparatus 100 may use optics and sensors optimized for use at 532 nanometers.

[0048] In yet another exemplary mode of operation, referring again to Figures 1 and 2, the apparatus 100 is configured to measure properties of an incident laser energy beam 10 having a wavelength of 1064 nanometers and a maximum optical power of approximately 1 kW propagating through the aperture optic 224. In this mode of operation, the first optical module 500 has an optical sensor 510 provided as a non-contact beam profiling system (e.g., the BEAMWATCH system discussed above) and the fourth optical module 600 has an optical sensor 610 provided as an optical power meter. In this mode of operation, the optical components 502 and 506 are not required since the non-contact beam profiling system 510 measures light Rayleigh scattered from the incident laser energy beam 10. Similarly, the third optical module 400 is not required since a beam dump is not required in the first section 230. Because optical components 502 and 506 are not used, the non-contact beam profiling system 500 can transmit a transmitted first optical module signal 508 having an optical power essentially equal to 1 kW of the incident laser energy beam 10 propagating through the aperture optic 224.

[0049] In this mode of operation, similar to the previously described modes of operation, the optical component 302 of the second optical module 300 is provided as a biconvex lens with a focal length of about 20 mm and anti-reflection coatings on both sides, allowing almost all of the optical power light to propagate through it. Also, one surface of the optical component 762 is left uncoated, allowing approximately 4-5% (depending on the angle of incidence or reflection, optical material, and laser wavelength) of the transmitted first optical module signal 508 to be reflected as a reflected window optical signal 766 to the optical power meter 610. The optical component 762 passes the transmitted window optical signal 764 through to the beam dump assembly 700 where it is absorbed by the absorber 800 and converted to thermal energy that is stored in the beam dump body 712. In this mode of operation, after approximately two minutes of operation, the beam dump body 712 reaches a predetermined temperature of approximately 50° C., and the temperature indicator 730 indicates to the operator that the beam dump assembly 700 should be replaced, so the operator shuts down the processing laser, removes the hot beam dump assembly 700 (i.e., the “first” beam dump assembly) from the beam dump receiver 270, and replaces it with a cold beam dump assembly 700 (i.e., the “second” beam dump assembly). The beam dump assembly 700 is then allowed to cool so that it is again usable.

[0050] While the exemplary modes of operation described above may be examples of typical uses of apparatus 100, one of ordinary skill in the art will appreciate that apparatus 100 may be configured in any desired or useful manner. If an operator needs to set up apparatus 100 for operation at a different wavelength or power level, apparatus 100 may be reconfigured by removing any combination of aperture assembly 220, optical modules 300, 400, 500, 600, or optical window assembly 760 and replacing them with other apertures, optical modules, or windows optimized for the different wavelengths or power levels.

[0051] The above describes the embodiments and examples of the present invention and should not be construed as being limiting thereto. Although some specific embodiments and examples have been described with reference to the drawings, those skilled in the art will readily recognize that many modifications to the disclosed embodiments and examples and other embodiments are possible without significantly departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications to the subject matter described herein are intended to be included within the scope of the present invention as defined in the claims. For example, those skilled in the art will understand that the subject matter of any sentence, paragraph, example or embodiment can be combined with some or all of the subject matter of any other sentence, paragraph, example or embodiment, unless such combinations are mutually exclusive. Thus, the scope of the present invention should be determined by the following claims and the equivalents of such claims to be included therein.

Claims

1. a housing including at least one first housing member and at least one second housing member; a first compartment formed within the housing; a second compartment formed within the housing; a first optical module located in the first compartment, the first optical module configured to measure a first property of the beam of laser energy; a first beam dump assembly removably positioned within the second compartment, the first beam dump assembly configured to absorb a portion of the laser energy beam; A laser measurement device comprising:

2. 10. The laser measurement device of claim 1, further comprising an aperture assembly mounted to the first housing member, the aperture assembly configured to pass a laser energy beam for propagation into the first compartment.

3. a second housing member formed within the housing; the second housing member is capable of reducing the transfer of thermal energy between the second compartment and the first compartment. The laser measurement device according to claim 1 .

4. 2. The laser measurement device of claim 1, wherein the first property of the laser energy beam is selected from the group consisting of beam diameter, beam shape, beam parameter product, optical power, optical intensity, beam pulse power, beam pulse energy, beam waist, and beam radius.

5. The laser measurement device of claim 1 , wherein the first optical module includes a laser beam profiler.

6. The laser measurement device of claim 1 , further comprising a fourth optical module configured to measure a second property of the beam of laser energy.

7. 7. The laser measurement device of claim 6, wherein the second property of the laser energy beam is selected from the group consisting of beam diameter, beam shape, beam parameter product, optical power, optical intensity, beam pulse power, beam pulse energy, beam waist, and beam radius.

8. 7. The laser measurement device according to claim 6, wherein the fourth optical module includes an optical power meter.

9. The laser measurement device of claim 1 , wherein the first optical module includes an optical component configured to receive the laser energy beam and propagate therethrough a transmitted first optical module signal.

10. 7. The laser measurement device of claim 6, further comprising an optical element configured to receive a transmitted first optical module signal, reflect a reflected window optical signal to the fourth optical module, and pass a transmitted optical window signal to propagate into the second section.

11. The laser measurement device of claim 1 , further comprising a second optical module installed in the first section, the second optical module including an optical component configured to pass and propagate a transmitted first optical module signal.

12. The laser measurement device of claim 11 , wherein the second optical module includes a removable optical mount configured to hold the optical component.

13. The laser measurement device of claim 12 further comprising at least one optical mount receiver configured to removably hold the removable optical mount therein.

14. The laser measurement device of claim 11 , wherein the optical component is configured to attenuate the transmitted first optical module signal.

15. the first beam dump assembly The beam dump body, an absorber in thermal communication with the beam dump body; The laser measurement device of claim 1 , comprising:

16. 16. The laser measurement apparatus of claim 15, wherein the first beam dump assembly is configured to be removed from the second compartment so that a second beam dump assembly can be placed within the second compartment.

17. 16. The laser measurement apparatus of claim 15, wherein the first beam dump assembly further comprises a temperature indicator configured to indicate a temperature of the beam dump body.

18. Housing and a first optical module including a first optical sensor disposed within the housing, the first optical module configured to measure a first property of the beam of laser energy; a first beam dump assembly removably positioned within the housing, the first beam dump assembly configured to absorb a portion of the laser energy beam; A laser measurement device comprising:

19. 20. The laser measurement device of claim 18, wherein the first beam dump assembly is configured to be removable from the housing to allow a second beam dump assembly to be positioned within the housing.

20. 20. The laser measurement device of claim 18, wherein the first optical module is selected from the group consisting of an aperture, an attenuator, a beam dump, a beam profiling camera, a beam profiler, an optical power meter, an optical energy meter, a beam splitter, a filter, a mirror, a lens, and a window.

21. 20. The laser measurement device of claim 18, wherein the first property of the laser energy beam is selected from the group consisting of beam diameter, beam shape, beam parameter product, optical power, optical intensity, beam pulse power, beam pulse energy, beam waist, and beam radius.

22. 20. The laser measurement apparatus of claim 18, further comprising a temperature indicator in thermal communication with the first beam dump assembly, the temperature indicator configured to indicate a temperature of the first beam dump assembly.

23. 20. The laser measurement device of claim 18, further comprising a fourth optical module disposed within the housing, the fourth optical module configured to measure a second property of the beam of laser energy.

24. 24. The laser measurement device of claim 23, wherein the second property of the laser energy beam is selected from the group consisting of beam diameter, beam shape, beam parameter product, optical power, optical intensity, beam pulse power, beam pulse energy, beam waist, and beam radius.

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