# US 5,349,591 A · Laser pulse stretcher and compressor with single parameter wavelength tunability > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,591 A - Document ID: US5349591A - Status: Granted - Kind: A - Application number: 08/052,778 - Filed: 1993-04-26 - Granted: 1994-09-20 - Earliest claimed: 1993-04-26 - Assignees: Positive Light, Inc. - Inventors: Jeremy Weston; William E. White - Web page: https://patentgrep.com/patent/US5349591A ## CPC - H01S 3/0057: {Temporal shaping, e.g. pulse compression, frequency chirping (soliton generation and propagation G02F1/3513, H01S3/063 and H01S3/108)} - H01S 3/005: {Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping (shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B)} - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract A dispersive laser pulse stretcher and compressor comprises a stretcher portion and a compressor portion. A first mirror, a second mirror, a third mirror, a first grating, a first lens, and a first vertical retroreflector block comprise the stretcher portion. A fourth mirror, a second grating, a horizontal retroreflector, and a second vertical retroreflector block preferably comprise the compressor portion. The input beams for the stretcher and compressor are preferably parallel beams. The present invention also positions the first grating of the stretcher in a parallel plane with the second grating of the compressor. The present invention also includes a method for simultaneously aligning the input angles of the stretcher and compressor, the method comprises the steps of: removing the first and second diffraction gratings; aligning the input beam for the stretcher portion; aligning the input beam for the compressor portion; mounting the first and second gratings on a mounting block in parallel planes, and rotating the mounting block until the proper input angle for the laser wavelength is reached. ## Claims ### Claim 1 A laser pulse stretcher and compressor comprising: a stretcher portion having a first diffraction grating for receiving a laser pulse and stretching the pulse, the stretcher portion receiving a first input beam to the stretcher portion along a first axis, the first diffraction grating positioned for receiving the first input beam with an input side of the first diffraction grating; and a compressor portion having a second diffraction grating for receiving a laser pulse and compressing the pulse, the compressor portion receiving a second input beam along a second axis, the second axis parallel to the first axis, the second diffraction grating positioned for receiving the second input beam with an input side of the second diffraction grating, and the second diffraction grating being positioned in a plane parallel to a plane in which the first diffraction grating is positioned. ### Claim 2 A laser pulse stretcher and compressor comprising: a stretcher portion having a first diffraction grating for receiving a laser pulse and stretching the pulse, the stretcher portion receiving a first input beam to the stretcher portion along a first axis, the first diffraction grating positioned for receiving the first input beam with an input side of the first diffraction grating; and a compressor portion having a second diffraction grating for receiving a laser pulse and compressing the pulse, the compressor portion receiving a second input beam along a second axis, the first axis being collinear with the second axis, the second diffraction grating positioned for receiving the second input beam with an input side of the second diffraction grating, and the second diffraction grating being positioned in a plane parallel to a plane in which the first diffraction grating is positioned. ### Claim 3 A laser pulse stretcher and compressor comprising: a stretcher portion having a first diffraction grating for receiving a laser pulse and stretching the pulse, the stretcher portion receiving a first input beam to the stretcher portion along a first axis, the first diffraction grating positioned for receiving the first input beam with an input side of the first diffraction grating; a compressor portion having a second diffraction grating for receiving a laser pulse and compressing the pulse, the compressor portion receiving a second input beam along a second axis, the second axis parallel to the first axis, the second diffraction grating positioned for receiving the second input beam with an input side of the second diffraction grating; and wherein the first diffraction grating and the second diffraction grating are mounted in parallel planes to a rotatable block for providing single parameter alignment of input angles to the first and second diffraction gratings by rotation of the block. ### Claim 4 A laser pulse stretcher and compressor comprising: a stretcher portion having a first diffraction grating, a first mirror, a lens and a retroreflector for receiving a laser pulse and stretching the pulse, the stretcher portion receiving a first input beam to the stretcher portion along a first axis, the first diffraction grating positioned for receiving the first input beam with an input side of the first diffraction grating; the first mirror optically coupled to the first diffraction grating for receiving and transmitting an optical beam; the lens positioned between the first mirror and the first diffraction grating, said lens optically coupling the first diffraction grating and the first mirror, and the retroreflector positioned along the first axis, the retroreflector optically coupled to the first diffraction grating for receiving an optical beam and transmitting the beam back to the diffraction grating along a parallel path; and a compressor portion having a second diffraction grating for receiving a laser pulse and compressing the pulse, the compressor portion receiving a second input beam along a second axis, the second axis parallel to the first axis, the second diffraction grating positioned for receiving the second input beam with an input side of the second diffraction grating, and the second diffraction grating being positioned in a plane parallel to a plane in which the first diffraction grating is positioned. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the first mirror is positioned one focal length away from the lens at an angle of about 90 degrees relative to the beam received from the first grating. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein the retroreflector comprises a second mirror and a third mirror, the second mirror and the third mirror positioned in planes at a right angle to each other. ### Claim 7 (depends on 4) The apparatus of claim 4, wherein the retroreflector comprises a single mirror, slightly tiled downwards. ### Claim 8 A laser pulse stretcher and compressor comprising: a stretcher portion having a first diffraction grating for receiving a laser pulse and stretching the pulse, the stretcher receiving a first input beam to the stretcher portion along a first axis, the first diffraction grating positioned for receiving the first input beam with an input side of the first diffraction grating; and a compressor portion having a second diffraction grating, a horizontal retroreflector, and a vertical retroreflector for receiving a laser pulse and compressing the pulse, the compressor portion receiving a second input beam along a second axis, the second axis parallel to the first axis, the second diffraction grating positioned for receiving the second input beam with an input side of the second diffraction grating, and the second diffraction grating being positioned in a plane parallel to a plane in which the first diffraction grating is positioned, the horizontal retroreflector positioned to receive an optical beam from the second grating, the horizontal retroreflector optically coupled to the second diffraction grating to receive an optical beam and transmit the beam back to the second diffraction grating along a parallel path shifted in the horizontal direction, and the vertical retroreflector positioned to receive an optical beam from the second grating, the vertical retroreflector optically coupled to the second diffraction grating to receive an optical beam and transmit the beam back to the second diffraction grating along a parallel path shifted in the vertical direction. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the vertical and horizontal retroreflectors each comprises a first mirror and a second mirror, the first mirror and the second mirror positioned in planes at a right angle to each other. ### Claim 10 A laser pulse stretcher and compressor comprising: a rotatable block; a stretcher portion having a first diffraction grating for receiving a laser pulse and stretching the pulse, the stretcher portion receiving a first input beam to the stretcher portion at a first angle, the first diffraction grating positioned for receiving the first input beam with an input side of the first diffraction grating, the first angle measured between a first axis and the input side of the first diffraction grating, the first diffraction grating mounted on the rotatable block; and a compressor portion having a second diffraction grating for receiving a laser pulse and compressing the pulse, the compressor portion receiving a second input beam at a second angle, the second diffraction grating positioned for receiving the second input beam with an input side of the second diffraction grating, the second angle measured between a second axis and the input side of the second diffraction grating, the second diffraction grating mounted on the rotatable block, the second diffraction grating positioned relative to the first diffraction grating such that the second angle is equal to the first angle and a change in the first angle resulting from a displacement in the position of the first diffraction grating caused by rotation of the rotatable block results in an identical change in the second angle.