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JP-7857256-B2 - Device and method for optical coherence tomography in laser material processing processes

JP7857256B2JP 7857256 B2JP7857256 B2JP 7857256B2JP-7857256-B2

Inventors

  • マルシン・コザック
  • ジョヴァンニ・バルバロッサ

Assignees

  • ツー－シックス デラウェア インコーポレイテッド

Dates

Publication Date
20260512
Application Date
20230713
Priority Date
20221021

Claims (16)

  1. A laser that generates a light beam, wherein the light beam collides with a lens matrix located between the laser and a beam splitter, The lens matrix includes an M x N microlens capable of generating an M x N matrix of light beams from the colliding light beams, A beam splitter that directs a first portion of the M×N light beam onto a mirror on a reference arm and a second portion of the M×N light beam onto an unknown surface on a measuring arm, wherein the first portion of the M×N light beam is reflected back from the mirror to the beam splitter, and the second portion of the M×N light beam is reflected back from the unknown surface to the beam splitter, A beam splitter capable of generating an interference signal by interfering the first reflected portion of the M×N light beam with the second reflected portion of the M×N light beam, A detector that receives the aforementioned interference signal and A device for a laser material processing process, comprising , wherein the matrix of M × N light beams and, therefore, the matrix of M × N pixels of interference signals, can be controlled individually.
  2. A device according to claim 1, wherein the matrix of M × N light beams and, therefore, the matrix of M × N pixels of the interference signal can be individually controlled by moving the microlenses.
  3. A device according to claim 1 or 2 , wherein the detector is a camera.
  4. A device according to claim 1 or 2 , wherein the detector is a monochrome camera or a color camera.
  5. A device according to claim 1 or 2 , wherein the microlenses are polygonal such that the microlenses are arranged with substantially no space between them.
  6. A device according to claim 1 or 2 , wherein the mirror is coupled to a drive unit for moving the mirror in the direction of the beam path of the light beam.
  7. A device according to claim 1 or 2 , further comprising a unit for evaluating the detected interference signal, wherein the detector is connected to the unit for evaluating the data.
  8. A method for monitoring an unknown surface in a laser material processing process, A step of generating a light beam using a laser, wherein the light beam collides with a lens matrix located between the laser and a beam splitter, A step of generating a matrix of M x N light beams from the colliding light beams using the lens matrix which includes M x N microlenses, A step of using the beam splitter to direct a first portion of the M×N light beam onto a mirror on a reference arm and a second portion of the M×N light beam onto an unknown surface on a measuring arm, wherein the first portion of the M×N light beam is reflected back from the mirror to the beam splitter, and the second portion of the M×N light beam is reflected back from the unknown surface to the beam splitter. The beam splitter comprises the step of generating an interference signal by interfering the first reflected portion of the M x N light beam with the second reflected portion of the M x N light beam, The steps of receiving the interference signal in the detector and A method comprising the following, wherein the matrix of M × N light beams and, therefore the matrix of M × N pixels of the interference signal can be controlled individually.
  9. A method according to claim 8, further comprising the step of individually controlling the matrix of M × N light beams and, therefore, the matrix of M × N pixels of the interference signal by moving the microlenses.
  10. A method according to claim 8 or 9 , wherein the step of receiving the interference signal is performed by a camera.
  11. A method according to claim 8 or 9 , wherein the received interference signal is evaluated by an evaluation unit connected to the detector.
  12. A method according to claim 11 , wherein the results of the evaluation are shown as an image on a display.
  13. A method according to claim 8 or 9 , wherein the individually controlled light beams and pixels may include motion in the X or Y direction.
  14. A method according to claim 11 , wherein the evaluation is used to control a process in a laser material processing process.
  15. A method according to claim 8 or 9 , wherein the laser material processing step is a welding step or a material cutting step.
  16. A method according to claim 8 or 9 , for monitoring the joining process when joining workpieces with a laser beam.

Description

Cross-reference of related applications [0001] This patent application claims priority and interest under German patent application DE10 1022 003 907.9, filed in Deutsches Patent-und Markenamt on 21 October 2022. The aforementioned application is incorporated herein by reference. [0002] This disclosure relates to a device and method for optical coherence tomography in laser material processing processes. [0003] Aspects of this disclosure relate to devices and methods for optical coherence tomography in laser material processing processes. Various challenges may exist in conventional solutions for optical coherence tomography in laser material processing processes. In this regard, conventional systems and methods for optical coherence tomography may be expensive, cumbersome, and/or inefficient. [0009] This figure shows the configuration for OCT measurement.[0010] This figure shows the configuration for measurement using OCT. [0011] The following description provides various examples of semiconductor devices and methods for manufacturing semiconductor devices. Such examples are not limiting, and the scope of the appended claims should not be limited to the specific examples disclosed. In the following description, the terms “example” and “for example” are not limiting. [0012] The figures show a schematic representation of the structure, and well-known features, technical descriptions, and details may be omitted to avoid unnecessarily obscuring this disclosure. In addition, elements in the drawings are not necessarily depicted to a constant scale. For example, the dimensions of some elements in the figures may be exaggerated compared to others to aid in understanding the examples described in this disclosure. The same reference numeral in different figures represents the same element. [0013] The term “or” means any one or more items in the list linked by “or.” For example, “x or y” means any element of the three-element set {(x), (y), (x, y)}. For another example, “x, y, or z” means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. [0014] The terms “equip,” “include,” “have,” and/or “possess” are “non-exclusive” terms that identify the presence of the described feature but do not exclude the presence or addition of one or more other features. [0015] Terms such as “first,” “second,” etc., may be used herein to describe various elements, and these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. Therefore, for example, the first element discussed herein may be referred to as the second element without departing from the teachings of this disclosure. [0016] Unless otherwise specified, the term “combined” may be used to describe two elements that are in direct contact with each other, or two elements that are indirectly connected by one or more other elements. For example, when element A is combined with element B, element A may be in direct contact with element B, or indirectly connected to element B by an intervening element C. Similarly, the terms “above” or “on top” may be used to describe two elements that are in direct contact with each other, or two elements that are indirectly connected by one or more other elements. [0017] Optical coherence tomography (OCT) is a technique that can be used for high-resolution cross-sectional imaging. OCT uses light and can be used, for example, to acquire cross-sectional images of tissue structures in situ and in real time at the micrometer scale. The use of OCT in combination with catheters and endoscopes can enable high-resolution intraluminal imaging of organ systems. [0018] OCT can function as a type of optical biopsy and can be a powerful imaging technique for medical diagnosis, for example, for use in ophthalmology. [0019] OCT can also be used for material processing processes. For example, an OCT configuration may use a single low-coherence light source and detector in combination with a deflection mirror. This technique can generate a single “pixel” that is swept across the entire field that may be of interest for process monitoring. However, in some examples, the speed and quality of the measured data may be limited when advanced optical elements and electronics may be required for data acquisition and processing. According to various embodiments of the present invention, monitoring of material processing processes using OCT can be improved. [0020] For example, micro-optical elements may be arranged in the optical path of the OCT between the laser source and the beam splitter so that an M×N matrix of independent sub-elements corresponding to the number of micro-optical elements can be used for measurement instead of, for example, one laser source corresponding to one pixel. [0021] The sub-elements may be combined in a kind of matrix in the sense of light beams or pixels, and each sub-element may be controlled separately. Light may be projected onto the surface