Modular laser apparatus

Abstract

A laser apparatus includes a plurality of laser modules each generating a laser line in a working plane. The laser modules are juxtaposed so that the laser lines generated by the modules combine into a single laser line. Each of the laser modules includes at least one laser line generator. The laser line generator includes two linear arrays of strips of laser diodes each emitting a focused laser beam. The two linear arrays are arranged parallel to each other so that the strips are staggered. The two sets of parallel laser beams generated by the two linear arrays of strips, respectively, are merged into a single laser line by a set of mirrors. The linear arrays of strips of laser diodes and the mirrors are arranged so that the two sets of laser beams trace optical paths of the same length before being merged into a single laser line.

Claims

1. A laser apparatus comprising: a plurality of laser modules each generating a laser line in a working plane, said laser modules being juxtaposed and aligned along their length so that the laser lines generated by the modules combine into a single laser line, wherein each of the laser modules comprises two linear arrays of strips of laser diodes, in which the strips are aligned along their length, each emitting a focused laser beam, the two linear arrays being arranged parallel to each other so that the strips are staggered, two sets of parallel laser beams generated by the two linear arrays of strips, respectively, being merged into the single laser line through a set of mirrors, the linear arrays of strips of laser diodes and the mirrors being arranged so that the two sets of laser beams trace optical paths of the same length before being merged into the single laser line.

2. The laser apparatus as claimed in claim 1, wherein a single set of the two sets of laser beams, called a first set of laser beams, is redirected and guided by the set of mirrors into a plane of a second set of the two sets of laser beams, a linear array of the two linear arrays of strips of laser diodes emitting the first set of laser beams being shifted, in a propagation direction of the second set of laser beams, by a distance equal to an increase in length of the optical path due to redirection by the set of mirrors.

3. The laser apparatus as claimed in claim 2, wherein the first set of laser beams undergoes two orthogonal reflections and the linear array of strips of laser diodes is shifted by a distance equal to an initial distance between two propagation planes of the two sets of laser beams.

4. The laser apparatus as claimed in claim 2, wherein the set of mirrors comprises: a continuous mirror reflecting the first set of laser beams in a direction of the plane of the second set of laser beams; and a segmented mirror including at least as many mirror segments as the first set of laser beams comprises laser beams, each beam of the first set of laser beams being reflected by one mirror segment.

5. The laser apparatus as claimed in claim 4, wherein the segments of the segmented mirror are positioned so as to reflect the laser beams at a focal point of the laser beams.

6. The laser apparatus as claimed in claim 1, wherein the two sets of laser beams are reflected by the same angle so that, after reflection, two propagation planes of the two sets of laser beams coincide, a first set of the two sets of laser beams being reflected by a segmented mirror and a second set of the two sets of laser beams being reflected by a continuous mirror.

7. The laser apparatus as claimed in claim 6, wherein the segments of the segmented mirror are positioned so as to reflect the laser beams at a focal point of the laser beams.

8. The laser apparatus as claimed in claim 1, wherein the apparatus includes at least two mechanisms to generate a laser line, each mechanism generating a monochromatic laser line that differs from one or more other monochromatic laser lines by at least one of a wavelength and a polarization state.

9. The laser apparatus as claimed in claim 8, further comprising: a mechanism to combine laser lines allowing a plurality of laser lines to be merged into at least one of a single polychromatic laser line and a dual-polarization laser line.

10. The laser apparatus as claimed in claim 1, wherein the two linear arrays of strips of laser diodes comprise the same number of strips.

11. The laser apparatus as claimed in claim 1, wherein the plurality of laser modules includes at least 5 modules.

12. The laser apparatus as claimed in claim 1, wherein the plurality of laser modules includes at least 10 modules.

13. The laser apparatus as claimed in claim 1, wherein the single laser line has a total length longer than 1.2 m.

14. The laser apparatus as claimed in claim 1, wherein the single laser line has a total length longer than 2 m.

15. The laser apparatus as claimed in claim 1, wherein the single laser line has a total length longer than 3 m.

Description

BRIEF DESRIPTION OF THE DRAWINGS

(1) The modular laser apparatus of the present invention will now be described in greater detail with reference to the appended figures, in which:

(2) FIG. 1 is a perspective view of a first embodiment of a means for generating a laser line; and

(3) FIG. 2 is a perspective view of a second embodiment of a means for generating a laser line.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(4) FIG. 1 shows two linear arrays 1a, 1b of strips of laser diodes. The linear arrays 1a, 1b are arranged on top of each other with a lateral shift such that the strips 2 are positioned staggered relative to one another. Each of the strips 2 generates a focused laser beam 3a, 3b. For the sake of simplicity, each of the linear arrays 1a, 1b here comprises only two strips. When the linear arrays comprise more than two strips, the latter are regularly spaced, each linear array of strips thus emitting a set of regularly spaced laser beams. The first set of beams 3a generated by the strips 2 of the bottom linear array 1a undergoes two successive orthogonal reflections: a first upward reflection ensured by a continuous mirror 4, then a second reflection ensured by a series of mirror segments 5, also referred to as a segmented mirror. The beams 3b of the top linear array 1b of strips of laser diodes are not reflected.

(5) The segments of the segmented mirror 5 cut the propagation plane of the second set of beams 3b and are positioned in the intervals between the beams of the second set of beams 3b, more particularly near focal points 6 of the latter where the intervals between beams are maximal. The staggered arrangement of the strips 2 of the two linear arrays 1a, 1b means that, in this position, the mirrors 5 intercept and reflect the beams of the first set of beams 3a emitted by the bottom linear array 1a of strips of diodes.

(6) These beams are focused so as to be reflected by the mirror segments 5 at their focal point.

(7) The focus of the two sets of beams 3a, 3b is therefore set so that all the focal points are aligned on a given straight line, which is essentially superposed on the straight line defined by the second orthogonal reflection of the first set of laser beams 3a.

(8) After the second orthogonal reflection of the first set of laser beams 3a, the two sets of beams propagate in the same plane, thus forming a single laser line 8.

(9) It is essential in the present invention for the two sets of laser beams 3a, 3b to trace optical paths having the same length before being merged in a single propagation plane.

(10) This is why the bottom linear array 1a of strips is shifted forward relative to the top linear array, i.e. in the direction of propagation of the beams 3b of this top linear array 1b. This shift compensates for the increase in length of the optical path seen by the first set of beams due to its double reflection. In the present case, this increase in length is equal to the distance between the initial propagation planes, in other words to the distance between the two reflections undergone by the first set of beams.

(11) In the second embodiment shown in FIG. 2, the two sets of beams 3a, 3b generated by the two linear arrays 1a, 1b of strips are each reflected a single time.

(12) The first linear array 1a and the second linear array 1b, located above the first, each comprise two strips 2. The first set of beams 3a generated by the first linear array 1a is reflected at right angles by a segmented mirror 5 positioned at the focal point of the beams, each mirror segment 5 reflecting one beam 3a.

(13) The second set of beams 3b emitted by the second linear array 1b of strips first propagates parallel to the first set of beams 3a, then, when its propagation plane cuts the second propagation plane of the first set of beams 1a, the second set of beams undergoes an identical reflection to that of the first set of beams, which causes the propagation planes of the two sets of beams to superpose.

(14) The focuses of the first and second sets of beams are identical and the second linear array 1b of strips is positioned so that the focal points of all the beams 3a, 3b are aligned level with the segmented mirror 5. The mirror 4 reflecting the second set of beams 3b is a continuous mirror.