# US 2019/0170636 A1 · Configurable retro-reflective sensor system for the improved characterization of the properties of a sample > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170636 A1 - Document ID: US20190170636A1 - Status: Published application - Kind: A1 - Application number: 16/306,492 - Filed: 2017-06-01 - Published: 2019-06-06 - Earliest claimed: 2016-06-02 - Assignees: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. - Applicants: Fraunhofer-Gesellschaft Zur FöRderung Der Angewandten Forschung E. V. - Inventors: Matthias HARTRUMPF; Christian NEGARA - Web page: https://patentgrep.com/patent/US20190170636A1 ## CPC - G01N 21/211: {Ellipsometry (optical thickness measurement G01B11/06)} - G01N 21/21: Polarisation-affecting properties (G01N21/19 takes precedence) - G01N 21/255: {Details, e.g. use of specially adapted sources, lighting or optical systems} - G01N 21/55: Specular reflectivity - G02B 5/122: cube corner, trihedral or triple reflector type - G01N 2021/216: {using circular polarised light} - G01N 2021/551: {Retroreflectance} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Disclosed is a retroreflector-based sensor system for optical characterization of a sample, having a transmitter for irradiating the sample, a retroflector positioned behind the sample, the transmitter, the sample, and the retroreflector being positioned such that radiation reflected back from the retroreflector is again incident on the sample and is reflected back from the latter in the direction towards the transmitter, and a receiver which is positioned in the receiving beam path such that it detects radiation reflected back from the retroreflector, incident again on the sample and reflected back from the latter, in the direction towards the transmitter. ## Claims ### Claim at position 1 1-11. (canceled) ### Claim 12 A retroreflector-based sensor system for optical characterisation of a sample, having a transmitter for irradiating the sample which is positioned in the transmitter beam path, a retroflector which is positioned behind the sample in the transmitter beam path such that it reflects radiation in the transmitter beam path coming from the sample and incident thereon in the receiving beam path back onto the sample, the transmitter, the sample, and the retroreflector being positioned such that radiation reflected back from the retroreflector in the receiving beam path is again incident on the sample and is reflected back from the latter in the direction towards the transmitter, and a receiver which is positioned in the receiving beam path such that it detects radiation reflected back from the retroreflector, incident again on the sample and reflected back from the latter, in the direction towards the transmitter, from the radiation detected by the receiver, measured values being obtainable and evaluatable for optical characterisation of the sample, and one or more configuration means being provided, by means of which improved obtaining and/or evaluation of the measured values is/are possible, for improved optical characterisation of the sample. ### Claim 13 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein one or more of the configuration means is/are configured and/or positioned in order to move the transmitter, the sample, the retroflector and/or the receiver, in particular mechanically, whilst the radiation is detected by the receiver. ### Claim 14 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein one or more of the configuration means include/s (an) optical element(s) which change/s, modulate/s and/or switch/es one or more parameters of the radiation. ### Claim 15 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein one of the configuration means is the receiver itself, by the latter being configured such that, from the radiation detected by it and also by it or by an evaluation unit of the sensor system, the entire polarisation state of this radiation or the complete Stokes vector of this radiation can be determined. ### Claim 16 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein one or more of the configuration means is/are (a) means for obtaining additional information about the sample and/or about the radiation of the transmitter beam path. ### Claim 17 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein one or more of the configuration means is/are a means for standardisation of the measured values. ### Claim 18 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein one or more of the configuration means is/are positioned or configured in the transmitter beam path, in the receiving beam path, in/on the transmitter, in/on the retroreflector, in/on the receiver, in/on a housing including or comprising both the transmitter and the receiver, or is/are provided such that the sample, the retroreflector or one of the configuration means can be scanned optically by it/them. ### Claim 19 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein the transmitter, the retroreflector, and the receiver are configured and positioned such that the radiation which is reflected back at the retroreflector, viewed relative to the transmitter beam path, widens in at least portions of the receiving beam path on the identical path or widens on a path offset thereto. ### Claim 20 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein the transmitter, the sample and the retroflector are positioned in reflection arrangement, the light coming therefore from the transmitter in the transmitter beam path and radiated onto the sample is reflected at the sample, coming from there is incident on the retroreflector, is reflected back from the retroreflector into the receiving beam path and onto the sample, is reflected again at the sample and finally is detected by the receiver as radiation which has been reflected twice at the sample, or the transmitter, the sample, and the retroreflector are positioned in transmission arrangement, the light coming therefore from the transmitter in the transmitter beam path and radiated onto the sample is transmitted through the sample, coming from there is incident on the retroreflector, is reflected back by the retroreflector into the receiving beam path and onto the sample, is transmitted again through the sample and finally is detected by the receiver as radiation which has been transmitted twice through the sample. ### Claim 21 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein the transmitter and the receiver are positioned adjacent to each other, directly adjacent to each other or as closely adjacent to each other as possible, or the receiver is positioned in a spatial region in which the transmitter is also positioned, or the transmitter and the receiver are integrated or positioned in or inside one and the same housing. ### Claim 22 (depends on 12) The retroreflector-based sensor system according to claim 12, wherein the transmitter and the receiver are configured as a point-measuring system, or the transmitter and the receiver are configured as a scanner system.