Process wherein several radiation sources, arranged in one row or several rows, are imaged, and apparatus for this purpose

• US 5,243,619 A
• Filed: 10/30/1991
• Issued: 09/07/1993
• Est. Priority Date: 11/01/1990
• Status: Expired due to Term

• Current Assignee: Fisba Optik AG, Bystronic Laser AG (Invico Asset Management AG)
• Original Assignee: Fisba Optik AG, Bystronic Laser AG (Invico Asset Management AG)
• Inventors: Albers, Peter, Langenbach, Eckhard, Heimbeck, Hans-Jorg
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): Wise, Robert E.
• Application Number:
  US07/785,062
• Time in Patent Office: 678 Days
• Field of Search: 372/70-72, 372/75, 372/92, 372/97, 359/494, 359/495, 359/496, 359/618, 359/619, 359/625, 359/626, 359/639, 359/640
• US Class Current: 372/97
• CPC Class Codes: G02B 13/08 Anamorphotic objectives
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 27/09 Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005
• CPC Class Codes: G02B 27/0966 Cylindrical lenses cylindrical lenses per se G02B3/06
• CPC Class Codes: G02B 3/06 with cylindrical or toric faces
• CPC Class Codes: 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
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence

Abstract

In the process and by means of the apparatus, several radiation sources (1) arranged in a row, whose emitted radiation intensity distribution is not rotationally symmetrical, are imaged by means of a first, noncentrically imaging functional element (5), then each beam bundle (9) is rotated by means of a beam-rotating element (7), and the beam components of the rotated beam bundles (9) not imaged by the first functional element (5) are imaged by means of a second, noncentrically imaging functional element (11). The functional elements (5, 11) and their locations are chosen so that parallel beam bundles (9) are produced which are focused with a spherical lens (15) into a spatial zone (3). The apparatus according to this invention provides in a simple way a good focusing ability for several individual beams.

Claims

1. A method for imaging several radiation-sources (1) into a spatial-zone (3) comprising,

arranging said radiation-sources in one or several rows,

emitting a beam (9) of radiation from each radiation-source,

each beam (9) having a spatial intensity distribution that is not rotationally symmetrical in a plane (IVa--IVa, IVb--IVb) perpendicular to the direction of propagation of the beam (9),

spatially rotating said beam (9) by a rotation-angle about their direction of propagation by first optical means (7), and imaging said beam into said spatial-zone (3) by second optical means (5, 11, 15).

2. A method according to claim 1, wherein

each beam (9) emitted from each radiation source (1) having a largest and a smallest beam quality product evoked by a largest and a smallest aperture-angle of the radiation of each beam (9),

forming a difference-angle from the angle-bisector of said smallest and the angle-bisector of said largest aperture-angle in said plane, and

said rotation of each of said beams being done by said first optical means (7) by said rotation-angle equal to said difference-angle.

3. A method according to claim 1, wherein

said imaging step includes a first imaging-step done by said second optical means (5) in the optical-path of each beam (9) between the radiation-sources (1) and said first optical means (7), and

said first imaging-step being a noncentrical imaging of each beam (9).

4. A method according to claim 3 for imaging the radiation of radiation-sources (1) of at least one diode-array, including

arranging said radiation-sources (1) in one row forming the diode-array,

each beam (9) emitted form each radiation source (1) having a largest and a smallest beam quality product evoked by a largest and a smallest aperture-angle of the radiation of each beam (9),

forming a difference-angle from the angle-bisector of said smallest and the angle-bisector of said largest aperture-angle in said plane,

said smallest and said largest aperture-angle respectively of each emitted beam of said array being spatially parallel to one another,

making a first beam-shape-part of each beam (9) emitted by each radiation-source (1) parallel to a first plane perpendicular to the angle-bisector of said largest aperture-angle by said first imaging-step by a first part (5) of said second optical means (5, 11, 15),

spatially rotating said beams with first beam-shape-parts parallel to said first plane, by said rotation-angle by said first optical means (7), and subsequently

making a second beam-shape-part of each beam (9) parallel to a second plane perpendicular to the angle-bisector of said smallest aperture-angle by a second part (11) of said second optical means (5, 11, 15), and

then focussing by a third part (15) of said second optical means (5, 11, 15) into said spatial-zone (3).

5. Apparatus for imaging several radiation-sources (1) into a spatial-zone (3), comprising

said sources (1) being arranged in one or several rows,

each said source (1) emitting a beam (9) with a radiation intensity having a spatial-intensity-distribution not rotationally symmetrical,

said apparatus having two imaging-function-elements (5, 11, 15) and one beam-rotating-element (7) for rotating said spatial-intensity-distribution by a rotation-angle in a plane perpendicular to the propagation direction of said beam (9),

said beam-rotating-element (7) being arranged between said sources (1) and said spatial-zone (3).

6. Apparatus according to claim 5, wherein

each beam (9) form said sources having a largest and a smallest beam-quality-product evoked by a largest and a smallest aperture-angle of the radiation of each beam (9),

an angle-bisector of said smallest and an angle-bisector of said largest aperture-angle being separated by a difference-angle in the plane perpendicular to the propagation direction of said beam, and

said beam-rotating-element (7) rotating each beam (9) of each of said sources (1) by a rotation-angle equal to said difference-angle, especially by 90°

.

7. Apparatus according to claim 6, wherein

a second (11) of said two imaging-function-elements (5, 11, 15) arranged between said beam-rotating-element (7) and said spatial-zone (3),

said second imaging-function-element being a noncentrical imaging-function-element (11), and

said second imaging-function-element (11) being arranged for reducing said smallest aperture-angle of each beam (9) rotated by said beam-rotating-element (7).

8. Apparatus according to claim 7, including

a third imaging-function-element (15) arranged between said second imaging-function-element (11) and said spatial-zone (3), and

said third imaging-function-element being a centrally focussing-function-element (15) for focussing said beam (9) into said spatial-zone (3).

9. Apparatus according to claim 5, wherein

said beam-rotating-element (7) has respectively one reversing-prism (27) per radiation-source (1).

10. Apparatus according to claim 5, wherein

a first (5) of said two imaging-function-elements (5, 11, 15) arranged between said rotation-source (1) and said beam-rotating-element (7),

said first imaging-function-element (5) being a noncentrical imaging-function-element (5), and

said first imaging-function-element (5) being arranged for reducing said largest aperture-angle of each beam (9).

11. Apparatus according to claim 5, in which said two imaging-function-elements are noncentrical imaging-function-elements and comprise cylindrical lenses, the beams from said sources being respectively in partial, and said cylindrical lenses located in the path of the beams from said sources operative to maintain the beams approximately in parallel.

12. Apparatus according to claim 5, in which said radiation-sources comprise at least one diode laser array, the radiation from which is imaged into said spatial-zone.

13. Apparatus for imaging several radiation-sources (1) into a spatial-zone (3), comprising

said sources (1) being arranged in at least two rows,

each said source (1) emitting a beam (9) with a radiation intensity having a spatial-intensity-distribution not rotationally symmetrical,

said apparatus having two noncentrical imaging-function-elements (5, 11, 15) and one beam-rotating-element (7) for rotating said spatial-intensity-distribution by a rotation-angle in a plane perpendicular to the propagation path of said beam (9),

said beam-rotating-element (7) being arranged between said sources (1) and said spatial-zone (3), and

at least one reflecting comb positioned after said beam-rotating-element and said imaging-function-elements in the propagation path of said beams and before said spatial-zone to combine the beams from said at least two rows of radiation sources.