Laser processing apparatus including a laser sensor system and method for measuring beam characteristics

Abstract

An optical device is disclosed. In one embodiment, the device includes a detector device having a photodetector, a first optical component configured to direct a first beam path through which a laser energy beam is propagatable toward a first optical train configured to direct the first beam path toward the photodetector, and a second optical component configured to direct a second beam path through which a laser energy beam is propagatable toward a second optical train configured to direct the second beam path toward the photodetector. The first optical train and the second optical train include a partially transmissive mirror and a curved mirror configured to image an AOD pivot point at a position relative to the detector device by propagating a first portion of the laser energy beam. The photodetector may be located within a detection port of an integrating sphere.

Description

Technical Field

[0001] Cross-reference to related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 348,165, filed Jun. 2, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] Technical field The embodiments described herein generally relate to laser processing apparatuses, and more particularly, to laser sensor systems for processing workpieces, their components, and methods for operating the same.

Background Art

[0003] Background Laser processing systems or apparatuses are used in a wide variety of applications including printed circuit board (PCB) machining, additive manufacturing, and the like. To process a PCB, for example, precise control of ablation of the PCB material (such as metals, insulators, those used for via formation, etc.) is required when laser processing is used to form holes or vias. Accurate and repeatable measurement of the power or energy of the processing laser beam is important for controlling the ablation process used to form these holes or vias. The laser sensor systems required for these precise measurements can be complex, expensive, and bulky. Thus, there is a need for laser sensor systems that provide consistent precise results with low system complexity and low cost. The embodiments described herein have been developed in view of these and other problems discovered by the inventors.

[0004] FIG. 1 shows a laser sensor system 30. The laser sensor system 30 includes mirrors 32a, 32b, 34a, 34b and photodetectors 36a and 36b, respectively. Mirrors 32a and 32b are provided to direct light propagating along beam paths 14a and 14b from the first positioner 106 towards mirrors 34a and 34b. Mirrors 32a and 32b are provided as turning mirrors, and mirrors 34a and 34b are provided as partially transmissive mirrors configured to reflect most of the light in the incident laser energy beam and send a small amount of light to detector 36a. The portions of the laser energy beam not sent by the partially transmissive mirrors 34a and 34b are directed towards scan heads 120a and 120b, respectively. Detector 36a is arranged to receive the light transmitted through partially transmissive mirror 34a, and detector 36b is arranged to receive the light transmitted through partially transmissive mirror 34b. Detectors 36a and 36b are configured to detect or measure the laser energy or power sent thereto and generate sensor data based on this detection or measurement. SUMMARY OF THE INVENTION

[0005] Summary One embodiment of the present invention can be characterized as a device comprising a detector device including a photodetector, at least one first optical component arranged to direct a first beam path along which a laser energy beam can propagate towards a first optical train configured to direct the first beam path towards the detector device, and at least one second optical component configured to direct a second beam path along which the laser energy beam can propagate towards a second optical train configured to direct the second beam path towards the detector device. The first optical train and the second optical train are configured to image an image of an AOD pivot point at a relative position with respect to the detector device. The device further comprises at least one laser source capable of generating the laser energy beam.

[0006] The first optical column and the second optical column may include a partial transmission mirror and a curved mirror. The partial transmission mirror is arranged to receive the laser energy beam, transmit a first portion of the laser energy beam, and reflect a second portion of the laser energy beam. The curved mirror is arranged to receive the first portion of the laser energy beam from the partial transmission mirror and reflect the first portion of the laser energy beam toward the detector device. In one embodiment, the detector device is an integrating sphere. The apparatus may further include a switch configured to selectively propagate the laser energy beam along the first beam path or the second beam path. The switch may be an AOD system or a galvanometer system. The optical detector device may include an integrating sphere having an integrating sphere body formed with a light collection port and a detection port, and the optical detector may be located within the detection port.

[0007] Other embodiments of the present invention include a detector device including a photodetector, a first laser source capable of generating a first laser energy beam, a second laser source capable of generating a second laser energy beam, a first beam path through which the first laser energy beam or the second laser energy beam can propagate, and at least one first optical component arranged to direct the first beam path toward a first optical train configured to direct the first beam path toward the detector device, and a second beam path through which the first laser energy beam or the second laser energy beam can propagate, and at least one second optical component arranged to direct the second beam path toward a second optical train configured to direct the second beam path toward the detector device. The device can be characterized as such. The first optical train and the second optical train are configured to project an image of the AOD turning point at a relative position with respect to the detector device. The first optical train and the second optical train may include a partially transmissive mirror and a curved mirror. The partially transmissive mirror receives the first laser energy beam or the second laser energy beam, propagates a first portion of the first laser energy beam or a first portion of the second laser energy beam, and reflects a second portion of the first laser energy beam or a second portion of the second laser energy beam. The curved mirror receives the first portion of the first laser energy beam or the first portion of the second laser energy beam from the partially transmissive mirror and is arranged to reflect the first portion of the first laser energy beam or the first portion of the second laser energy beam toward the detector device. The device may further include a switch configured to selectively propagate the first laser energy beam or the second laser energy beam through the first beam path or the second beam path. The switch can be an AOD system or a galvanometer system. The photodetector device may include an integrating sphere having an integrating sphere body in which a light collection port and a detection port are formed, and the photodetector is located within the detection port.

Brief Description of the Drawings

[0008] Brief description of the drawings Figure 1 Figure 1 schematically shows a laser sensor system for a laser processing apparatus. Figure 2 Figure 2 schematically shows a laser processing apparatus according to an embodiment. Figure 3 Figure 3 schematically shows a laser sensor system according to an embodiment. Figure 4 Figure 4 schematically shows a multi-source laser processing apparatus according to an embodiment. Figure 5 Figure 5 schematically shows a multi-source laser processing apparatus according to another embodiment. Figure 6 Figure 6 schematically shows the position of a beam path entering an integrating sphere according to an embodiment. Figure 7 Figure 7 schematically shows the position of a beam path entering an integrating sphere according to another embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0009] Detailed description Hereinafter, examples of embodiments will be described with reference to the accompanying drawings. Unless otherwise explicitly stated, in the drawings, the sizes, positions, and distances between components, features, elements, etc. are not necessarily to scale and are exaggerated for ease of understanding. The same numbers throughout the drawings mean the same elements. For this reason, even if the same or similar numbers are not mentioned or explained in the corresponding drawings, they may be described with reference to other drawings. Also, even elements without reference numbers may be described with reference to other drawings.

[0010] The terms used in the specification are for the purpose of describing particular exemplary embodiments only and are not intended to be limiting. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. As used herein, the singular forms are intended to include the plural forms as well, unless the content clearly indicates otherwise. Further, the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise indicated, when a range of values is recited, the range is intended to include not only the sub-ranges between the upper and lower limits of the range, but also the upper and lower limits themselves. Unless otherwise indicated, terms such as "first" and "second" are used only to distinguish elements from each other. For example, a certain node can be referred to as "the first node," and similarly, another node can be referred to as "the second node," or vice versa.

[0011] Unless otherwise indicated, terms such as "about" and "around" mean that the quantity, size, composition, parameters, and other quantities and characteristics need not be exact and may be approximate, reflecting, as appropriate, tolerances, conversion factors, rounding, measurement errors, and other factors known to those skilled in the art, and may be larger or smaller. In this specification, spatially relative terms such as "downward", "below", "lower", "upward", and "upper" may be used for ease of explanation when describing the relationship of one element or feature to another element or feature as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations in addition to the orientation shown in the figures. For example, an element described as "downward" or "below" another element or feature will face "upward" of the other element or feature when the object in the figure is inverted. Thus, the exemplary term "downward" can include both upward and downward orientations. When the object faces other orientations (e.g., rotated 90 degrees or in other orientations), the spatially relative descriptors used in this specification can be interpreted accordingly.

[0012] The section headings used in this specification are for organization purposes only and should not be construed as limiting the described subject matter, unless otherwise specifically referred to. 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 limited to the examples of embodiments described herein. Rather, these examples and embodiments are provided so that the present disclosure is complete and inclusive and conveys the scope of the present disclosure to those skilled in the art.

[0013] I. System overview FIG. 2 schematically shows a laser processing apparatus according to an embodiment of the present invention.

[0014] Referring to the embodiment shown in FIG. 2, a laser processing apparatus 100 (also simply referred to as the "apparatus" in this specification) for processing workpieces 102a and 102b (collectively referred to as "workpiece 102") can be characterized as including a laser source 104 for generating a laser energy beam, a first positioner 106, a plurality of second positioners (for example, second positioners 108a and 108b. Collectively referred to as "second positioner 108"), a third positioner 110, and a plurality of scan lenses (for example, scan lenses 112a and 112b. Collectively referred to as "scan lens 112"). FIG. 2 shows an embodiment in which the laser processing apparatus 100 includes two second positioners 108, but it will be understood that many of the embodiments disclosed herein can be applied to laser processing apparatuses including more than two second positioners 108. Further, the laser processing apparatus 100 includes a laser sensor system such as a laser sensor system 130 configured to measure characteristics of the laser energy beam (for example, power, energy, beam diameter, etc.) and provide measurement data representing these characteristics to the controller 122.

[0015] The scan lens 112 and the corresponding second positioner 108 can be optionally integrated into a common housing or "scan head". For example, the scan lens 112a and the corresponding second positioner 108 (i.e., the second positioner 108a) can be integrated into a common scan head 120a. Similarly, the scan lens 112b and the corresponding second positioner 108 (i.e., the second positioner 108b) can be integrated into a common scan head 120b. As used in this specification, each of the scan head 120a and the scan head 120b is also collectively referred to as "scan head 120".

[0016] FIG. 2 shows a single third positioner 110 that commonly supports a plurality of workpieces 102, but it will be understood that a plurality of third positioners 110 (e.g., for supporting different workpieces 102, for supporting a common workpiece 102, etc., or any combination thereof) can be provided. However, it should be recognized from the following description that it is optional to include the second positioner 108 or the third positioner 110 if the functions provided by the second positioner 108 or the third positioner 110 are not required.

[0017] As described in more detail below, the first positioner 106 is capable of diffracting, reflecting, refracting, or deflecting the laser energy beam so as to deflect the beam path 114 to any of the second positioners 108. As used herein, the term "beam path" means the path through which the laser energy in the laser energy beam travels when propagating from the laser source 104 to the scan lens 112. When deflecting the beam path 114 to the second positioner 108a, the beam path 114 can be deflected by any angle within a first angular range (also referred to herein as the "first primary angular range 116a") (e.g., this is measured with respect to the beam path 114 incident on the first positioner 106). Similarly, when deflecting the beam path 114 to the second positioner 108b, the beam path 114 can be deflected by any angle within a second angular range (also referred to herein as the "second primary angular range 116b") (e.g., this is measured with respect to the beam path 114 incident on the first positioner 106). As used herein, each of the first primary angular range 116a and the second primary angular range 116b is also collectively referred to as the "primary angular range 116". Generally, the first primary angular range 116a does not overlap or touch the second primary angular range 116b. The first primary angular range 116a may be larger than, smaller than, or equal to the second primary angular range 116b. As used herein, deflecting the beam path 114 within one or more of the primary angular ranges of the primary angular range 116 is referred to herein as "beam splitting".

[0018] Each second positioner 108 is capable of diffracting, reflecting, refracting, or the like, or any combination thereof (i.e., "steering") the laser energy beam generated by the laser source 104 and steered by the first positioner 106 so as to steer the beam path 114 to the corresponding scan lens 112. For example, the second positioner 108a can steer the beam path 114 to the scan lens 112a. Similarly, the second positioner 108b can steer the beam path 114 to the scan lens 112b. When steering the beam path 114 to the scan lens 112a, the second positioner 108a can steer the beam path 114 at any angle within a first angular range (also referred to herein as the "first secondary angular range 118a") (e.g., this is measured with respect to the optical axis of the scan lens 112a). Similarly, when steering the beam path 114 to the scan lens 112b, the second positioner 108b can steer the beam path 114 at any angle within a second angular range (also referred to herein as the "second secondary angular range 118b") (e.g., this is measured with respect to the optical axis of the scan lens 112b). The first secondary angular range 118a may be larger than, smaller than, or equal to the second secondary angular range 118b.

[0019] The laser energy steered to the scan lens 112 is typically focused by the scan lens 112 so as to irradiate the workpiece 102 and transmitted along the beam axis. For example, the laser energy steered and transmitted to the scan lens 112a irradiates the workpiece 102a, and the laser energy steered to the scan lens 112b irradiates the workpiece 102b. The laser energy irradiating the workpiece 102 can be characterized as having a Gaussian spatial intensity profile or a non-Gaussian (i.e., "shaped") spatial intensity profile (e.g., "top hat" spatial intensity profile, super-Gaussian spatial intensity profile, etc.).

[0020] FIG. 1 shows a plurality of workpieces 102 arranged so as to intersect different beam axes, but it will be understood that one larger workpiece 102 may be processed by laser energy irradiated from a plurality of scan lenses. Further, FIG. 1 shows a plurality of scan lenses 112 arranged to transmit laser energy propagating along beam paths deflected by different second positioners 108, but it will be understood that the apparatus 100 may be configured such that laser energy propagating along beam paths deflected by a plurality of second positioners 108 passes through a common scan lens 112 (e.g., using mirrors, prisms, beam splitters, etc., or any combination thereof).

[0021] A. Laser source In one embodiment, the laser source 104 can generate laser pulses. For this reason, the laser source 104 can include, for example, a pulsed laser source, a CW laser source, a QCW laser source, a burst mode laser, or any arbitrary combination thereof. When the laser source 104 includes a QCW laser source or a CW laser source, the laser source 104 may operate in a pulse mode or may operate in a non-pulse mode, but may further include a pulse gating unit (for example, an acousto-optic (AO) modulator (AOM), a beam chopper, etc.) that temporally modulates the beam of laser emission output from the QCW laser source or the CW laser source. The laser source 104 can be operated in a "burst mode" in which a plurality of individual pulses can be grouped within a burst envelope. Within the burst envelope, the power of each pulse and the time between each pulse can be adjusted to match specific laser processing requirements. In this way, the laser source 104 can be broadly characterized as being capable of generating a laser energy beam that can be represented as a series of laser pulses that can then propagate along the beam path 114, or as a continuous or quasi-continuous laser beam. Although some embodiments described herein refer to laser pulses, it should be understood that continuous beams or quasi-continuous beams can be used alternatively or additionally where appropriate or necessary.

[0022] In addition to the wavelength, average power, and pulse duration and pulse repetition rate when the laser energy beam is represented as a series of laser pulses, the laser energy beam irradiated onto the workpiece 102 can be characterized by one or more other characteristics such as pulse energy, peak power, etc. Such characteristics are sufficient light intensity (measured in W / cm 2 to irradiate the process spot of the workpiece 102, such as fluence (measured in J / cm 2 ), etc., for processing the workpiece 102 (for example, to form one or more features), and (for example, as necessary) beam size, beam profile, polarization, beam parameter product (M 2)It can be selected based on one or more other characteristics such as spot size, pulse duration, average power, pulse repetition rate, etc.

[0023] B. First positioner The first positioner 106 is disposed, positioned, or installed within the beam path 114 and deflects or moves the beam path 114 (e.g., with respect to the scan lens 112), and as a result, deflects or moves the beam path 114 with respect to the workpiece 102. It operates to diffract, reflect, refract, or the like the laser pulse generated by the laser source 104, or to perform these arbitrarily in combination. For example, in one embodiment, the first positioner 106 is provided as an acousto-optic deflector (AOD) system capable of deflecting the beam path 114 by diffracting the incident laser beam. Generally, the first positioner 106 can move the beam axis 118 along the X-axis (or X-direction), Y-axis (or Y-direction), or a combination thereof with respect to the workpiece 102 (e.g., by deflecting the beam path 114 within the first primary angle range 116a, within the second primary angle range 116b, or within the range of a combination thereof). Although not shown, the Y-axis (or Y-direction) can be understood to mean an axis (or direction) orthogonal to the illustrated X-axis (or X-direction) and Z-axis (or Z-direction).

[0024] In one embodiment, the operation of the first positioner 106 may be controlled so as to deflect the beam path 114 to the second positioner 108a (e.g., during the first branching period), deflect the beam path 114 to the second positioner 108b (e.g., during the second branching period after the first branching period), or vice versa, or in combination thereof. In other examples, the operation of the first positioner 106 may be controlled so as to deflect the beam path 114 to the second positioner 108a and the second positioner 108b simultaneously.

[0025] C. Second positioner The second positioner 108 is installed within the beam path 114 and deflects or moves the beam path 114 (e.g., with respect to the scan lens 112), and as a result, deflects or moves the beam path 114 with respect to the workpiece 102. It operates to diffract, reflect, refract, or perform similar actions on the laser pulse generated by the laser source 104 and passing through the first positioner 106, or perform any combination thereof (i.e., "deflect" the laser pulse). Generally, the second positioner 108 can move the beam axis along the X-axis (or X-direction), Y-axis (or Y-direction), or a combination thereof with respect to the workpiece 102 (e.g., by deflecting the beam path 114 within the first secondary angle range 118a or the second secondary angle range 118b).

[0026] From the above perspective, it should be understood that the second positioner 108 can be provided as an AOD system, a galvanometer mirror scanning system, a rotating polygon mirror system, a variable mirror, a microelectromechanical system (MEMS) reflector, etc., or any combination thereof.

[0027] D. Third positioner The third positioner 110 can move the workpiece 102 (e.g., workpieces 102a and 102b) with respect to the scan heads 120a and 120b, and as a result, move the workpiece 102 with respect to the beam path 114.

[0028] In the illustrated embodiment, the third positioner 110 is arranged and configured to cause relative movement between the workpiece 102 and the scan lens 112, and as a result, cause relative movement between the workpiece 102 and the beam path 114 (e.g., it can impart translational movement to the workpiece 102 along the X, Y, and / or Z directions respectively), including one or more linear stages, (e.g., it can impart rotational movement to the workpiece 102 about an axis parallel to the X, Y, and / or Z directions respectively), one or more rotational stages, etc., or any arbitrary combination thereof. In the illustrated embodiment, the third positioner 110 is capable of moving the workpiece 102. However, in other embodiments, the third positioner 110 is arranged and operated to move the scan head and optionally one or more components such as the first positioner 106, and the workpiece 102 may remain stationary.

[0029] E. Scanning lens Generally, the scan lens 112 (provided as either a simple lens or a compound lens, for example) is configured to focus a laser energy beam directed along the beam path so as to generate a beam waist that can typically be located at or near the desired process spot.

[0030] F. Controller Generally, the apparatus 100 includes one or more controllers such as a controller 122 for controlling or facilitating the control and operation of the apparatus 100. In one embodiment, the controller 122 is communicatively coupled to one or more components of the apparatus 100 such as the laser source 104, the first positioner 106, the second positioner 108, the third positioner 110, etc. (e.g., via one or more wired or wireless communication links, optical fiber links, etc., or any arbitrary combination thereof), such that these components operate in response to one or more control signals output by the controller 122.

[0031] G. Embodiments related to laser sensor systems i. Embodiments of a laser sensor system using a single laser and a single detector In one embodiment, the apparatus 100 may comprise a laser sensor system having a common detector capable of measuring the optical power directed at a plurality of workpieces, thereby reducing system complexity and cost compared to a system having a plurality of detectors. For example, in a machining system having a plurality of scan heads, the laser energy beam may be measured using a first positioner that directs the beam path into separate optical trains during separate branching periods (e.g., by beam splitting or pulse slicing as described above). The separate optical trains each introduce a majority of the beam power into their respective scan heads and direct a portion of the beam (e.g., by a partially transmissive mirror) towards a common detector to measure the optical power.

[0032] Referring to FIG. 3, a laser sensor system, such as laser system 130, includes optical components 132a, 132b, optical trains 140a and 140b, and detector device 160. In this embodiment, the first optical train 140a includes a first mirror 142a and a first curved mirror 144a, and the second optical train 140b includes a second mirror 142b and a second curved mirror 144b. The detector device 160 includes an integrating sphere 162 having an integrating sphere body 164 with a light collection port 166, an inner surface 168, a detection port 170, and a photodetector 172 disposed within the detection port 170.

[0033] The optical components 132a and 132b are adapted to direct light propagating along the beam paths 114a and 114b deflected by the first positioner 106 (e.g., during the first branching period and the second bank period, respectively) through the first primary angle ranges 116a and 116b to the first optical column 140a and the second optical column 140b, respectively. The determination of the branching period during which the beam is measured can be determined by establishing the relationship between the time when the control command is sent by the controller 122 to the first positioner 106 and the time when the laser measurement data is received by the controller from a common detector. For this purpose, the controller 122 can be configured to determine which beam path (e.g., the beam path 114a or the beam path 114b shown in FIG. 3) is directed at the laser sensor system 130 by comparing the timing of a specific branching period (e.g., the first branching period or the second branching period described above) with the measurement data received by the controller 122.

[0034] The optical components 132a and 132b are provided, for example, as knife-edge mirrors (having, for example, specific surface characteristics such as flatness, roughness, and scratch / chip resistance over the entire at least one edge of the mirror), and the mirrors 142a and 142b can be provided as partially transmissive mirrors configured to reflect most of the light of the incident laser energy beam and transmit a small amount of light (e.g., about 2% or so) towards the mirrors 144a and 144b. The mirrors 144a and 144b are arranged to receive the light transmitted through the corresponding partially transmissive mirrors and reflect the light to the detector device 160. The light that does not pass through the partially transmissive mirrors 142a and 142b is directed towards the scan heads 120a and 120b, respectively. In some embodiments, imaging optics (e.g., focusing or collimating optics capable of changing the beam diameter and controlling the laser fluence) can also be introduced within or elsewhere in the optical columns 140a, 140b of the laser sensor system 130. In other embodiments, the optical components 132a and 132b can be provided as turn mirrors.

[0035] In the illustrated embodiment, the detector device 160 includes a photodetector 172 configured to detect or measure the incoming laser energy or power and generate sensor data representative of the detected or measured value. In other embodiments, the detector device 160 measures any number of beam characteristics including, but not limited to, beam diameter, M 2 and may include a laser beam profiler (not shown) configured to measure any number of beam characteristics such as beam propagation factor and generate sensor data representative of the beam profile measurement. The sensor data can be output to the controller 122 by any suitable means, and then the sensor data is processed in the controller 122 for various functions of the apparatus 100 such as real-time pulse energy control (e.g., to compensate for changes in laser power), system calibration (e.g., to compensate for transmission changes of the AOD system of the first positioner 106 with respect to RF power and frequency, etc.), or any arbitrary combination thereof.

[0036] Since the detector device 160 is located optically downstream of the first positioner 106, the reading by the photodetector 172 can vary depending on the position or angle of the energy beam incident on the photodetector 172. Thus, movement of the incident laser energy beam at the photodetector 172 can cause a reading error, which may result in incorrect power control, system calibration, etc. To reduce or eliminate the spatial and directional sensitivities associated with the photodetector, each of the laser sensor systems may include a beam expander and / or a diffuser (not shown) arranged to expand and / or diffuse the laser energy beam before it strikes the photodetector 172. For this purpose, in the embodiment shown in FIG. 3, the laser sensor system 130 may include an integrating sphere 162 disposed optically upstream of the photodetector 172 to reduce the spatial and directional sensitivities associated with the photodetector 172. The integrating sphere 162 may be provided as an alternative to, or to supplement, the above-described use of the beam expander / diffuser. Generally, as is known in the art, the integrating sphere 162 is an optical component that includes a hollow sphere (or beam expander sphere) having a cavity, the inner surface of which is coated with a diffuse reflection coating. The integrating sphere 162 is arranged such that light propagating from the partial transmission mirrors (i.e., from mirrors 142a or 142b) can enter through the light collection port 166 into the cavity of the corresponding integrating sphere 162 and be incident on the inner surface 168. Light incident at any point on the inner surface of the cavity is scattered and eventually exits the integrating sphere 3016 at the detection port and is incident on a photodetector (identified as 3018 in this embodiment). At least a portion of the light incident at any point on the inner surface 168 of the cavity is scattered and exits the integrating sphere 162 at the detection port 170 and is finally incident on the photodetector 172. The light that did not transmit toward the detector device 160 in the partial transmission mirrors 142a and 142b is directed toward the scan heads 120a and 120b, respectively.

[0037] In one embodiment, the first positioner 106 may function as a switch capable of selecting a beam path (i.e., the first beam path 114a and / or the second beam path 114b) through which laser energy propagates.

[0038] ii. Embodiments of a laser sensor system using a single detector together with multiple laser sources Certain embodiments of the present invention provide an apparatus having a plurality of laser sources (also referred to herein as a "multi-source apparatus"). Each of the laser sources may direct laser energy at one of a plurality of workpieces, or both of the laser sources may direct laser energy at a single workpiece. By using two laser sources, a laser processing apparatus having additional processing flexibility and / or higher throughput may be provided. The laser sources may be provided to operate at substantially the same wavelength and substantially the same spectral bandwidth. For example, in one embodiment, the first laser source and the second laser source are capable of generating a laser energy beam having one or more wavelengths in the visible light (e.g., green) region of the electromagnetic spectrum. In other embodiments, one of the wavelength and spectral bandwidth of the laser energy generated by the first laser source may be different from that of the laser energy generated by the second laser source (e.g., greater than, less than, or any arbitrary combination thereof).

[0039] FIG. 4 schematically shows an embodiment of a multi-source device such as device 200 configured to have a plurality of laser sources and a laser sensor system 130 as described above with respect to FIG. 3. As shown in FIG. 4, device 200 includes a first laser source 204a and a second laser source 204b. Generally, both the first laser source 204a and the second laser source 204b are capable of generating sufficient laser energy to process workpieces 102a and 102b shown in FIG. 1. Each of the first laser source 204a and the second laser source 204b may be provided as exemplarily described above with respect to laser source 104. Laser energy from the first laser source 204a propagates along a first beam path 214a to a first primary positioner 206a, and laser energy from the second laser source 204b propagates along a second beam path 214b to a second primary positioner 206b. The first primary positioner 206a is capable of diffracting, reflecting, refracting, or deflecting the laser energy beam so as to deflect the beam path 214a to either the first scan head 120a or the second scan head 120b. Similarly, the second primary positioner 206b is also capable of diffracting, reflecting, refracting, or deflecting the laser energy beam so as to deflect the beam path 214b to either the first scan head 120a or the second scan head 120b. The first primary positioner 206a and the second primary positioner 206b are each provided as an AOD system (such as the first positioner 106 described above), but may be provided as other desired or suitable types of positioners (for example, a galvanometer mirror scanning system, a rotating polygon mirror system, a variable mirror, a microelectromechanical system (MEMS) reflector, etc., or any arbitrary combination thereof).

[0040] When deflecting the beam path 214a to the first scan head 120a, the beam path 214a can be deflected by an arbitrary angle within the first angular range (also referred to herein as the "first primary angular range 216a") by the first primary positioner 206a (for example, this is measured with respect to the beam path 214a incident on the first primary positioner 206a). In addition, the first primary positioner 206a can deflect the beam path 214a to the second scan head 120b within another first angular range (also referred to herein as the "another first primary angular range 216c") (for example, this is measured with respect to the beam path 214a incident on the second primary positioner 206b).

[0041] Similarly, when deflecting the beam path 214b to the second scan head 120b, the beam path 214b can be deflected by an arbitrary angle within the second angular range (also referred to herein as the "second primary angular range 216b") by the second primary positioner 206b (for example, this is measured with respect to the beam path 214b incident on the second primary positioner 206b). In addition, the second primary positioner 206b can deflect the beam path 214b to the first scan head 120a within another second angular range (also referred to herein as the "another second primary angular range 216d") (for example, this is measured with respect to the beam path 214b incident on the second primary positioner 206b).

[0042] In this embodiment, the laser sensor system 130 (as described above with respect to FIG. 3) is optically downstream of the first primary positioner 206a and the second primary positioner 206b such that either the beam path 214a or 214b can be directed to the detector device 160 before the beam paths 214a and 214b reach the first scan head 120a and the second scan head 120b (for example, when the beam paths 214a and 214b are deflected through the angular ranges 216a, 216b, 216c, or 216d, respectively, during, for example, the first, second, third, or fourth branching period or slice period).

[0043] The laser sensor system 130 is provided substantially the same as described above with respect to FIG. 3. The beam paths 214a and 214b can be directed to the first optical train 140a or the second optical train 140b by mirrors 132a and 132b, respectively. The portions of the light transmitted through the partially transmissive mirrors 142a and 142b are directed to the detector device 160 by the curved mirrors 144a and 144b, respectively, enter the light collection port 166 of the integrating sphere 162, exit from the detection port 170, and are detected by the photodetector 172. The portions of the light that do not pass through the partially transmissive mirrors 142a and 142b are directed to the scan heads 120a and 120b, respectively.

[0044] The determination of the branching period during which the beam is measured can be determined by establishing the relationship between the time when the control command is sent by the controller 122 to the first primary positioner 206a or the second primary positioner 206b and the time when the laser measurement data is received by the controller from the detector device 160. For this reason, the controller 122 can be configured to determine which beam path (e.g., 214a or 214b shown in FIG. 4) is to be measured by the laser sensor system 130 by comparing the timing of a specific branching period (e.g., the first branching period or the second branching period described above) with the measurement data received by the controller 122.

[0045] FIG. 5 schematically shows an embodiment of a multi-source device such as a device 300 configured to have a plurality of laser sources and a laser sensor system 130 as described above with respect to FIG. 3. As shown in FIG. 5, the device 300 includes a first laser source 304a and a second laser source 304b. Generally, both the first laser source 304a and the second laser source 304b can generate sufficient laser energy to process the workpieces 102a and 102b shown in FIG. 1. Each of the first laser source 304a and the second laser source 304b can be provided as exemplarily described above with respect to the laser sources 204a and 204b. In other embodiments, more than two laser sources may be provided.

[0046] In this embodiment, the laser energy from the first laser source 304a propagates along the first beam path 314a, and the laser energy from the second laser source 304b propagates along the second beam path 314b. The laser energy propagating along the first beam path 314a and the second beam path 314b may be spatially combined by any suitable method. For example, a fold mirror 380 may be provided that directs the first beam path 314a towards a beam combiner 382 that is also disposed within the second beam path 314b. After exiting the beam combiner 382, the laser energy may propagate along a common beam path 314c (corresponding to, for example, the beam path 114 shown in FIG. 1) towards the first positioner 306. The first positioner 306 deflects the laser energy beam by any angle (for example, this is measured with respect to the common beam path 314c incident on the first positioner 306) by diffracting, reflecting, refracting, or deflecting it through a first primary angular range 316a towards the first scan head 120a through the laser sensor system 130 (for example, during a first branching period or slice period), and through a second primary angular range 316b towards the second scan head 120b through the laser sensor system 130 (for example, during a second branching period or slice period). The determination of the branching period during which the beam is measured can be determined by establishing the relationship between the time at which the control command is sent by the controller 122 to the first positioner 306 and the time at which the laser measurement data is received by the controller from the detector device 160. For this purpose, the controller 122 may be configured to determine which angular range (for example, 316a or 316b shown in FIG. 5) is measured by the laser sensor system 130 by comparing the timing of a particular branching period (for example, the first branching period or the second branching period described above) with the measurement data received by the controller 122.

[0047] The laser sensor system 130 is provided substantially the same as described above with respect to FIG. 3. The beam path 314c can be directed by mirrors 132a and 132b through a first primary angular range 316a to a first optical train 140a and through a second primary angular range 316b to a second optical train 140b, respectively. The portions of the light that pass through the partially transmissive mirrors 142a and 142b are each directed by the curved mirrors 144a and 144b to the detector device 160, enter the light collection port 166 of the integrating sphere 162, exit through the detection port 170, and are detected by the photodetector 172. The portions of the light that do not pass through the partially transmissive mirrors 142a and 142b are each directed to the scan heads 120a and 120b, respectively.

[0048] iii. Embodiments related to the control of the position of the turning point with respect to the light collection port of the integrating sphere Generally, as described above, by using an integrating sphere for the measurement of optical power, the spatial and directional sensitivities associated with the measurement by the photodetector can be reduced. However, in embodiments where an integrating sphere is used, the sensor data representing the measured characteristics of the beam entering the integrating sphere can vary as a function of the position where the beam path enters the light collection port of the integrating sphere or as a function of the position on the inner surface of the integrating sphere where the beam is incident. Additionally, the sensor data representing the measured characteristics of the beam entering the integrating sphere (and the scattered light exiting the detection port) can vary as a function of the angle of the beam path (e.g., through the angular range by which the beam paths 114a, 114b, 214a, 214b, and 314c are deflected by the respective positioners 106, 206a, 206b, or 306) when entering the light collection port of the integrating sphere. To control or reduce such variations, the beam path can be directed (e.g., by the optical trains 140a and 140b) to the detector device 160 such that the image of the AOD turning point is consistently positioned with respect to the integrating sphere 162 (e.g., the light collection port 166 or the inner surface 168). For this reason, by positioning the AOD turning point at a specific point (e.g., the center of the entrance port), it is ensured that the beam enters the sphere in a spatially consistent manner such that the sensitivity of the detector signal to the scanning position or angle can be reduced.

[0049] Figures 6 and 7 schematically show embodiments of the detector device 160 in which the turning points are at different positions with respect to the light collection port 166 or the inner surface 168 of the integrating sphere 162. In these embodiments, the detector device 160 is provided as described above with respect to FIG. 3.

[0050] As shown in FIG. 6, since the first beam path 114a is deflected within the first primary angular range 116a, depending on the curvature of the curved mirror 144a of the first optical train 140a (shown in FIG. 3) or the presence of other optical elements of the first optical train 140a (or located optically upstream thereof), the curved mirror 144a directs the beam path 114a towards the integrating sphere 162 and projects an image of the AOD turning point onto the turning point 134a on the inner surface 168 of the integrating sphere 162. Similarly, since the second beam path 114b is deflected within the second primary angular range 116b, depending on the curvature of the curved mirror 144b of the second optical train 140b (shown in FIG. 3) or the presence of other optical elements of the second optical train 140b (or located optically upstream thereof), the curved mirror 144b directs the beam path 114b towards the integrating sphere 162 and projects an image of the AOD turning point onto the turning point 134b on the inner surface 168 of the integrating sphere 162. In this example, the positions of the turning points 134a and 134b on or near the surface 168 of the integrating sphere 162 can reduce the positional sensitivity of the optical power detected by the photodetector 172. When the laser sensor system 130 and the detector device 160 are provided in this way, the laser sensor system 130 and the detector device 160 can be used to provide a consistent measurement of the beams propagating along the beam paths 114a and 114b. Although not shown in FIG. 6, the same applies to the beam paths 214a and 214b and (for example, since these are deflected within the respective angular ranges 216a, 216c, 216b, and 216d as shown in FIG. 4) 314c and (for example, since this is deflected within the angular ranges 316a and 316b).

[0051] As shown in FIG. 7, since the first beam path 114a is deflected within the first angular range 116a, depending on the curvature of the curved mirror 144a of the first optical train 140a (shown in FIG. 3) or the presence of other optical elements of the first optical train 140a (or located optically upstream thereof), the curved mirror 144a directs the beam path 114a towards the integrating sphere 162 and projects an image of the AOD pivot point onto the pivot point 136 at or near the center of the light collection port 166 of the integrating sphere 162. Due to the position of the pivot point 136 at or near the center of the light collection port 166, the beam path can be incident on the inner surface 168 of the integrating sphere 162 in a spatially consistent manner. Similarly, depending on the curvature of the curved mirror 144b (shown in FIG. 3) or the presence of other optical elements of the second optical train 140b (or located optically upstream thereof), the curved mirror 144b directs the beam path 114b towards the integrating sphere 162 and projects an image of the AOD pivot point onto the same pivot point 136 located at or near the center of the light collection port 166 of the integrating sphere 162. Thus, due to the position of the pivot point 136 at or near the center of the light collection port 166, the positional sensitivity of the optical power detected by the photodetector 172 can be reduced. When the laser sensor system 130 and the detector device 160 are provided in this way, the laser sensor system 130 and the detector device 160 can be used to provide a consistent measurement of the beams propagating along the beam paths 114a and 114b. Although not shown in FIG. 7, the same also applies to the beam paths 214a and 214b (since they are deflected within respective angular ranges 216a, 216c, 216b, and 216d as shown in FIG. 4, for example) and 314c (since it is deflected within the angular ranges 316a and 316b as shown in FIG. 5, for example).

[0052] II. Conclusion The above has described embodiments and examples of the present invention and should not be construed as being limited 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 improvements can be made to the disclosed embodiments and examples and to other embodiments without departing significantly from the novel teachings and advantages of the present invention. Accordingly, all such improvements are intended to be included within the scope of the present invention as defined in the following 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 the subject matter of some or all of the other sentences, paragraphs, examples or embodiments, except where such combinations are mutually exclusive. Therefore, the scope of the present invention should be determined by the following claims and the equivalents of the claims to be included therein.

Claims

1. A detector device including a photodetector, At least one first optical component arranged to direct a first beam path through which a laser energy beam can propagate towards a first optical train configured to direct the first beam path towards the detector device, At least one second optical component configured to direct a second beam path through which the laser energy beam can propagate towards a second optical train configured to direct the second beam path towards the detector device And a device comprising.

2. The device according to claim 1, wherein the first optical train and the second optical train are configured to image an AOD pivot point image at a relative position with respect to the detector device.

3. The device according to claim 1, further comprising at least one laser source capable of generating the laser energy beam.

4. The first optical train and the second optical train are A partially transmissive mirror, A curved mirror And a device according to claim 1.

5. The partially transmissive mirror is Receives the laser energy beam, Propagates a first portion of the laser energy beam, Reflects a second portion of the laser energy beam And is arranged as described in claim 4.

6. The device according to claim 5, wherein the curved mirror is arranged to receive the first portion of the laser energy beam from the partially transmissive mirror and reflect the first portion of the laser energy beam towards the detector device.

7. The device according to claim 1, wherein the detector device is an integrating sphere.

8. The apparatus according to claim 1, further comprising a switch configured to selectively propagate the laser energy beam along the first beam path or the second beam path.

9. The apparatus according to claim 8, wherein the switch is an AOD system.

10. The apparatus according to claim 8, wherein the switch is a galvanometer system.

11. The detector device comprises an integrating sphere having an integrating sphere body in which a light collection port and a detection port are formed, and the photodetector is located within the detection port. The apparatus according to claim 1.

12. A detector device including a photodetector; A first laser source capable of generating a first laser energy beam; A second laser source capable of generating a second laser energy beam; At least one first optical component arranged to direct a first beam path along which the first laser energy beam or the second laser energy beam can propagate, toward a first optical train configured to direct the first beam path toward the detector device; At least one second optical component arranged to direct a second beam path along which the first laser energy beam or the second laser energy beam can propagate, toward a second optical train configured to direct the second beam path toward the detector device and an apparatus comprising the same.

13. The apparatus according to claim 12, wherein the first optical train and the second optical train are configured to image an AOD pivot point at a relative position with respect to the detector device.

14. The first optical train and the second optical train include a partially transmissive mirror; Curved mirror and The apparatus according to claim 12, comprising

15. The partial transmission mirror receives the first laser energy beam or the second laser energy beam, propagates a first portion of the first laser energy beam or the second laser energy beam, and reflects a second portion of the first laser energy beam or the second laser energy beam The apparatus according to claim 14, arranged to

16. The curved mirror receives the first portion of the first laser energy beam or the second laser energy beam from the partial transmission mirror and is arranged to reflect the first portion of the first laser energy beam or the second laser energy beam towards the detector device. The apparatus according to claim 15.

17. The apparatus according to claim 12, further comprising a switch configured to selectively propagate the first laser energy beam or the second laser energy beam along the first beam path or the second beam path.

18. The switch is an AOD system. The apparatus according to claim 17.

19. The switch is a galvanometer system. The apparatus according to claim 17.

20. The detector device comprises an integrating sphere having an integrating sphere body in which a light collecting port and a detection port are formed, and the photodetector is located within the detection port. The apparatus according to claim 12.

Images