Optical arrangement for use in a laser diode system

• US 5,808,803 A
• Filed: 09/02/1997
• Issued: 09/15/1998
• Est. Priority Date: 01/11/1995
• Status: Expired due to Term

• Current Assignee: Arnd Kosters, Christopher Ullmann, Volker Krause
• Original Assignee: Arnd Kosters, Christopher Ullmann, Volker Krause
• Inventors: Krause, Volker, Ullmann, Christopher, Kosters, Arnd
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US08/860,472
• Time in Patent Office: 378 Days
• Field of Search: 359/641, 359/204, 359/618
• US Class Current: 359/641
• 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 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/425 Optical features semiconductor laser arrays H01S5/40; hybrid LED arrays H01L25/0753; monolithic LED arrays H01L27/153
• 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

An optical arrangement for collimation of a plurality of laser beams of several emitters or emitter groups of a laser diode arrangement which are located in one row or in several rows, the emitters or emitter groups of one row being located with their active layer in one common plane with a stipulated distance A in one axial direction, the arrangement including two sets of cylindrically acting collimation optics, wherein the arrangement includes means for deflection of the laser beams after passage through the two sets of collimation optics which are present parallel to one another in different beam planes offset against one another.

Claims

1. An optical arrangement for collimation of a plurality of laser beams of several emitters or emitter groups of a laser diode arrangement which are located in one row or in several rows, the emitters or emitter groups of one row being located with their active layer in one common plane and with a stipulated distance in one axial direction, the optical arrangement comprising

first cylindrical collimation optics which causes collimation of said plurality of laser beams of the emitters or emitter groups in a first plane (Y-Z planes) which is perpendicular to a first coordinate direction (X axis), and

second cylindrical collimation optics which cause collimation of said plurality of laser beams of the emitters or emitter groups in a second plane (X-Z planes) which is perpendicular to said first plane (Y-Z plane) and also perpendicular to a second coordinate direction (Y axis), wherein the optical arrangement comprises means for deflection of said plurality of laser beams of adjacent emitters or emitter groups in said first plane (Y-Z plane) such that collimated laser beams of said adjacent emitters or emitter groups after passage through said second cylindrically acting collimation optics are present parallel to one another in different beam planes offset against one another.

2. The optical arrangement as claimed in claim 1, wherein the emitters or emitter groups of each row are located in said first coordinate direction (X axis) with a stipulated distance (a).

3. The optical arrangement as claimed in claim 1, wherein beam planes in one axial direction (offset direction) are perpendicular to said first coordinate direction (X axis), and offset against one another in a second or a third coordinate direction (Y axis or Z axis).

4. The optical arrangement as claimed in claim 1, wherein the emitters or emitter groups of said laser diode arrangement are imaged in a common spacial area or focal point following said second cylindrically acting collimation optics by focussing optics by which said plurality of laser beams are imaged into said common spacial area or said focal point.

5. The optical arrangement as claimed in claim 1, further comprising deflection means in a beam path between said first cylindrically acting collimation optics and said second cylindrically acting collimation optics such that said plurality of laser beams are arranged parallel to one another in different beam planes before entering the second collimation optics.

6. The optical arrangement as claimed in claim 1, wherein at least two beam planes are formed by deflection means of said plurality of laser beams.

7. The optical arrangement as claimed in claim 1, wherein said first and second cylindrically acting collimation optics are formed by at least one biconvex or plano-convex cylindrical lens with aspherical curvature, by at least one concave mirror or by optical means which image in the manner of a cylindrical lens.

8. The optical arrangement as claimed in claim 1, wherein said second cylindrically acting collimation optics in the beam planes has at least one collimation element at a time, and wherein said at least one collimation element is offset from beam plane to beam plane each time by an amount (a) in the first coordinate direction (X axis) which corresponds to said distance (a) of the emitters, or emitter groups of a row, or which is proportional to said distance (a).

9. The optical arrangement as claimed in claim 8, wherein said second cylindrically acting collimation optics is a cylindrical lens arrangement has at least one cylindrical lens element which is oriented with its cylindrical axis in the offset direction (Y axis) or perpendicular to the second plane (X-Z plane).

10. The optical arrangement as claimed in claim 9, wherein said cylindrical lens arrangement or said cylindrical lens element is made plano-convex.

11. The optical arrangement as claimed in claim 9, wherein said cylindrical lens arrangement or said cylindrical lens element is made spherical.

12. The optical arrangement as claimed in claim 9, wherein said second cylindrical lens arrangement or said cylindrical lens element is made aspherical.

13. The optical arrangement as claimed in claim 1, wherein the means for deflection of said plurality of laser beams have a first prism arrangement or first prism block which in the first coordinate direction (X axis) following one another has several prism elements, of which each is assigned to one emitter or emitter group, and their average distance in the first coordinate direction (X-axis) is equal to distance (a) of the emitters or emitter groups of one row, and wherein said prism elements cause a different deflection in the respective first plane (X-Z plane) due to a different incline of prism surfaces.

14. The optical arrangement as claimed in claim 1, wherein the means for deflection of said plurality of laser beams have a first light-reflecting or light-diffracting arrangement or a light-reflecting or light-diffracting element, which in the first coordinate direction (X axis) has several reflecting or light-diffracting areas in succession, with an average distance which is equal to distance (a) of the emitters or emitter groups.

15. The optical arrangement as claimed in claim 14, wherein said light-reflecting areas or said surfaces for different deflection of said plurality of laser beams in the first plane (Y-Z plane) have a different incline relative to the second plane (X-Z plane) or the plane of the active layer.

16. The optical arrangement as claimed in claim 1, wherein the means for deflection of said plurality of laser beams have a second prism block or a second prism arrangement which in the beam path or in the direction of the coordinate direction (Y axis or Z-axis) forms an optical axis of the arrangement and follows on first prism arrangement and on deflection element and which forms at least one prism element for each beam plane such that the deflected plurality of laser beams are converted into those in the parallel beam planes.

17. The optical arrangement as claimed in claim 1, wherein the means for deflection of said plurality of laser beams have a second reflecting or light-diffracting arrangement which in the beam path or in the direction of a coordinate direction (Z-axis) forms the optical axis of the arrangement and follows on a first prism arrangement or on a first reflecting or a light-diffracting element and which forms at least one reflection surface or light-diffracting area for each beam plane such that the deflected plurality of laser beams are converted into those in the parallel beam planes.

18. The optical arrangement as claimed in claim 1, wherein there are several rows of the emitters or emitter groups, wherein for each row there is an optical arrangement consisting at least of first collimation optics, of second collimation optics and of means for deflecting said plurality of laser beams of adjacent emitters or emitter groups into the different beam planes, the rows of emitters or emitter groups preferably being provided on top of one another in the second coordinate direction (Y axis).

19. The optical arrangement as claimed in claim 18, wherein second collimation optics or second prism arrangements or prism blocks or second light-reflecting or light-diffracting arrangements or focussing optics (13) for all rows or for a group of rows are combined into one optical assembly.

20. The optical arrangement as claimed in claim 1, further comprising focussing optics which has at least one rotationally-symmetrical collimating lens.