# US 2023/0055035 A1 · Adjustable attenuation optical unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0055035 A1 - Document ID: US20230055035A1 - Status: Published application - Kind: A1 - Application number: 17/404,900 - Filed: 2021-08-17 - Published: 2023-02-23 - Earliest claimed: 2021-08-17 - Assignees: Applied Materials Israel Ltd. - Applicants: Applied Materials Israel Ltd. - Inventors: Eitam Yitzchak Vinegrad; Itay Asulin - Web page: https://patentgrep.com/patent/US20230055035A1 ## CPC - G02B 6/3538: {based on displacement or deformation of a liquid (controlling the intensity of light by displacement or deformation of a fluid in general G02B26/004; fluid-filled lens of variable focal length G02B3/14)} - G02B 6/266: {the optical element being an attenuator} - H01J 37/244: Detectors; Associated components or circuits therefor - H01J 37/3045: {Object or beam position registration} - H01J 2237/2443: Scintillation detectors - H01J 2237/28: Scanning microscopes - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract An adjustable attenuation optical unit that may include a lightguide that includes a core, wherein the core comprises an output, an input and an exterior surface; and an adjustable attenuator that is configured to define an interfacing parameter related to an area of the exterior surface thereby receiving at least some of the light that impinges on the area. ## Claims ### Claim 1 An adjustable attenuation optical unit, comprising: a lightguide that comprises a core, wherein the core comprises an output, an input, and an exterior surface; and an adjustable attenuator configured to define an interfacing parameter related to an area of the exterior surface thereby receiving at least some of a light that impinges on the area. ### Claim 2 (depends on 1) The adjustable attenuation optical unit according to claim 1 wherein the adjustable attenuator is a light absorbing element that is configured to selectively contact the area. ### Claim 3 (depends on 1) The adjustable attenuation optical unit according to claim 1 wherein the adjustable attenuator is a light conduit that is configured to selectively contact the area. ### Claim 4 (depends on 1) The adjustable attenuation optical unit according to claim 1 wherein the adjustable attenuator is a light receiving element that is configured to move between (a) a first position in which the light receiving element contacts the area, and (b) a second position in which the light receiving element is spaced apart from the area. ### Claim 5 (depends on 1) The adjustable attenuation optical unit according to claim 1 wherein the adjustable attenuator is a light receiving element that is configured to move between (a) a first position in which the light receiving element contacts the area, and (b) a second position in which the light receiving element is spaced apart from the area, and (c) a third position in which the light receiving element contacts the area and another area of the exterior surface. ### Claim 6 (depends on 1) The adjustable attenuation optical unit according to claim 1 wherein the adjustable attenuator comprises a chamber and a fluid control unit, wherein the chamber has an interior portion that interfaces with the area and wherein the fluid control unit is configured to control a flow of fluid having a refraction index that exceeds the refraction index of air into the chamber. ### Claim 7 (depends on 6) The adjustable attenuation optical unit according to claim 6 wherein the fluid is liquid. ### Claim 8 (depends on 6) The adjustable attenuation optical unit according to claim 6 wherein the fluid is gas. ### Claim 9 (depends on 1) The adjustable attenuation optical unit according to claim 1 wherein the area is annular. ### Claim 10 (depends on 1) The adjustable attenuation optical unit according to claim 1 comprising a photomultiplier tube that is optically coupled to the lightguide. ### Claim 11 (depends on 10) The adjustable attenuation optical unit according to claim 10 wherein the area is located outside an optical path between the input and the photomultiplier tube. ### Claim 12 A method for setting an adjustable attenuation optical unit, the method comprising: setting a value of an interfacing parameter related to the adjustable attenuation optical unit; wherein the adjustable attenuation optical unit comprises a lightguide and an adjustable attenuator; wherein the lightguide comprises a core, wherein the core comprises an output, an input and an exterior surface; and wherein the adjustable attenuator is configured to define an interfacing parameter related to an area of the exterior surface thereby receiving at least some of a light that impinges on the area; and propagating light through the adjustable attenuation optical unit while subjecting the light to the interfacing parameter. ### Claim 13 (depends on 12) The method according to claim 12 comprising setting the value of the interfacing parameter based on a throughput of an evaluation of a sample; wherein the evaluation of the sample comprises: illuminating the sample with an electron beam; collecting emitted electrons that were reflected or scattered from the sample, and converting the emitted electrons to the light that propagates through the adjustable attenuation optical unit. ### Claim 14 (depends on 13) The method according to claim 13 comprising determining 1 transmission to exceed a transmission threshold, wherein the transmission threshold is a function of an intensity of the electron beam, an electron yield, an electron energy impact on the detector, and a collection parameter indicative of an amount of collected emitted electrons. ### Claim 15 (depends on 12) The method according to claim 12 wherein the adjustable attenuator is a light absorbing element and the method comprises selectively contacting the area by the light absorbing element. ### Claim 16 (depends on 12) The method according to claim 12 wherein the adjustable attenuator is a light conduit the method comprises selectively contacting the area by the light conduit. ### Claim 17 (depends on 12) The method according to claim 12 wherein the adjustable attenuator is a light receiving element and the method comprises moving the light receiving element between (a) a first position in which the light receiving element contacts the area, and (b) a second position in which the light receiving element is spaced apart from the area. ### Claim 18 (depends on 12) The method according to claim 12 wherein the adjustable attenuator is a light receiving element and the method comprises moving the light receiving element between (a) a first position in which the light receiving element contacts the area, and (b) a second position in which the light receiving element is spaced apart from the area, and (c) a third position in which the light receiving element contacts the area and another area of the exterior surface. ### Claim 19 (depends on 12) The method according to claim 12 wherein the adjustable attenuator comprises a chamber and a fluid control unit, wherein the chamber has an interior portion that interfaces with the area and the method comprises controlling, by the fluid control unit, a flow of fluid having a refraction index that exceeds the refraction index of air into the chamber. ### Claim 20 The method according to 12 wherein the area is annular.