# US 2012/0083771 A1 · Apparatus and method for processing material with focused electromagnetic radiation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0083771 A1 - Document ID: US20120083771A1 - Status: Published application - Kind: A1 - Application number: 12/894,375 - Filed: 2010-09-30 - Published: 2012-04-05 - Earliest claimed: 2010-09-30 - Assignees: Wavelight GmbH - Inventors: Berndt Warm; Peter Riedel; Claudia Gorschboth; Franziska Woittennek - Web page: https://patentgrep.com/patent/US20120083771A1 ## CPC - A61F 9/00836: {Flap cutting} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract An apparatus for processing material with focused electromagnetic radiation, comprises: a source emitting electromagnetic radiation, means for directing the radiation onto the material, means for focusing the radiation on or in the material, a unit for generating a pattern in the optical path of the electromagnetic radiation, an at least partially reflective surface in the optical path before the focus of the focused radiation, said pattern being imaged onto said at least partially reflective surface through at least part of said directing means and said focusing means, at least one detector onto which an image of the pattern is reflected by said surface and which generates electrical signals corresponding to said image, said image containing information on the position of the focus, a computer receiving said electrical signals and programmed to process said image so as to generate an electrical signal depending on the focal position, and a divergence adjustment element arranged in said optical path and adapted to receive said electrical signal of the computer so as to change a divergence of the electromagnetic radiation depending on said signal. ## Claims ### Claim 1 An apparatus for processing material with focused electromagnetic radiation, comprising: a source of electromagnetic radiation, optical components for directing and focusing the radiation on or in the material, a unit for generating a pattern in the optical path of the electromagnetic radiation, an at least partially reflective surface in the optical path before the focus of the focused radiation, said pattern being imaged onto said at least partially reflective surface through at least part of said optical components, at least one detector onto which an image of the pattern is reflected by said surface and which generates electrical signals corresponding to said image, said image containing information on the position of the focus, a computer receiving said electrical signals and programmed to process said image so as to generate an electrical signal depending on the focal position, and a divergence adjustment element arranged in said optical path and adapted to receive said electrical signal of the computer so as to change a divergence of the electromagnetic radiation depending on said signal. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein said surface is arranged at the location where the electromagnetic radiation exits the apparatus. ### Claim 3 (depends on 1) An apparatus according to claim 1, wherein the material is eye tissue, preferably the cornea. ### Claim 4 (depends on 1) An apparatus according to claim 1, wherein the source is a laser, preferably a femtosecond laser. ### Claim 5 (depends on 1) An apparatus according to claim 1, wherein said surface is an applanation surface which is adapted to be pressed against a cornea. ### Claim 6 (depends on 1) An apparatus according to claim 1, wherein the pattern comprises two or more dots. ### Claim 7 (depends on 1) An apparatus according to claim 1, wherein the divergence adjustment element comprises one of a telescope, a deformable mirror, and a deformable lens. ### Claim 8 (depends on 1) An apparatus according to claim 1, including two detectors, one of said detectors detecting radiation emitted by the source, and the other of said detectors detecting radiation reflected by the surface. ### Claim 9 (depends on 1) An apparatus according to claim 1, wherein the unit generating the pattern is disposed in the optical path of the electromagnetic radiation after the divergence adjustment element. ### Claim 10 (depends on 1) An apparatus according to claim 1, wherein the pattern comprises dots arranged in the form of a matrix. ### Claim 11 A method for processing material with focused electromagnetic radiation, comprising: generating electromagnetic radiation by means of a source, directing the radiation onto the material to be processed, focusing the radiation on or in the material, generating a pattern by means of the electromagnetic radiation, providing an at least partially reflective surface in the optical path of the electromagnetic radiation before the focus of the focused radiation, imaging said pattern on said at least partially reflective surface, detecting, by means of at least one detector, radiation reflected by said surface, the detected images containing information on the position of the focus, generating electrical signals representative of the detected images, processing said electrical signals in a computer so as to generate an electrical signal depending on the focal position, and adjusting the divergence of said emitted radiation depending on said electrical signal.