JP2013007805A - Light source unit, manufacturing method thereof, and beam shaping lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for adjustment work of a light source unit, with respect to a light source unit using a semiconductor laser, a manufacturing method thereof, and a beam shaping lens for use in the light source unit.SOLUTION: A light source unit 4 includes: a base 3; a semiconductor laser 1 disposed on the base 3; and a beam shaping lens 2 which is disposed on the base 3 and adjusts an aspect ratio of an elliptic luminous flux emitted from the semiconductor laser 1. The beam shaping lens 2 includes an optical function part 7 for adjusting the aspect ratio and a flange part 8 provided in the outer periphery of the optical function part 7, and an auxiliary lens 9 for alignment of the beam shaping lens 2 is provided in the flange part 8.

Description

  The present invention relates to a light source unit using a semiconductor laser, a manufacturing method thereof, and a beam shaping lens used therefor.

  In general, in a light source unit using a semiconductor laser, the light beam emitted from the semiconductor laser becomes an elliptical light beam with different divergence angles between the parallel direction and the vertical direction of the semiconductor junction surface. A beam shaping lens to be converted into a light beam is required.

  When adjusting the aspect ratio of the elliptical luminous flux, not only make the optical axis of the light beam emitted from the semiconductor laser coincide with the optical axis of the beam shaping lens, but also adjust the rotation with the optical axis of the beam shaping lens as the rotation axis. It is necessary to set so as to cancel the aspect ratio of the luminous flux.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

Japanese Patent Laid-Open No. 9-258099

  However, since such a light source unit has a structure in which a semiconductor laser and a beam shaping lens are integrated on a base, the semiconductor laser is arranged on the base, and then the beam shaping lens is separated from the semiconductor laser. In high-power applications such as projectors, there is a problem that adjustment work takes time due to stabilization of the output of the semiconductor laser and cooling after emission. there were.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such problems and to shorten the time required for the light source unit adjustment work.

  In order to achieve this object, the present invention includes a base, a semiconductor laser disposed on the base, and a beam shaping lens that adjusts the aspect ratio of an elliptical light beam disposed on the base and emitted from the semiconductor laser. The beam shaping lens has an optical function part for adjusting the aspect ratio and a flange part provided on the outer periphery of the optical function part, and an auxiliary lens for aligning the beam shaping lens on the flange part. Is provided.

  With this structure, the present invention can shorten the time required for adjusting the light source unit.

Side view of a light source unit according to the present invention Top view of the light source unit Front view of the beam shaping lens that composes the light source unit Schematic diagram showing the optical axis adjustment method in the arrangement of the beam shaping lens Schematic diagram showing the spacing adjustment method in the arrangement of the beam shaping lens Schematic diagram showing the molding equipment for the beam shaping lens

  Hereinafter, a light source unit according to an embodiment of the present invention will be described with reference to the drawings.

  FIGS. 1 and 2 show a light source unit 4 in which a semiconductor laser 1 and a beam shaping lens 2 are integrated on the main surface of a base 3, and the divergent light of an elliptical light beam emitted from the semiconductor laser 1 is shown. The beam shaping lens 2 has a function of adjusting the aspect ratio, converting it into a parallel light beam of circular light, and emitting it.

  Further, the beam shaping lens 2 adjusts the aspect ratio of the light beam emitted from the semiconductor laser 1 so that the lens structure has a different numerical aperture between the semiconductor bonding surface and the horizontal and vertical directions. A vertically long elliptical lens as shown by the broken line 5 in FIG. 3 is arranged on the incident surface, and a horizontally long elliptical lens as shown by the solid line 6 is arranged on the outgoing surface, so that a desired beam can be obtained with a single lens. The shaping is realized. The elliptical lens that adjusts the aspect ratio is defined as the optical function unit 7, and the flat region located on the outer periphery thereof is defined as the external connection flange unit 8.

  In order to assemble such a light source unit 4, first, the semiconductor laser 1 is disposed at a predetermined position on the base 3. There are various types of semiconductor lasers 1 such as a CAN type and a submount mounting type, but the position and angle of the semiconductor laser 1 are determined such as the contact surface provided on the base 3 and the thickness of solder used for bonding. It is possible to mount with high accuracy by the control. Therefore, the optical axis of the light beam emitted from the semiconductor laser 1 with respect to the base 3 is also determined with high accuracy.

  Next, the beam shaping lens 2 is disposed. At this time, the optical axis of the beam shaping lens 2 is made to coincide with the optical axis of the semiconductor laser 1, and the focal point of the beam shaping lens 2 is set on the emission surface of the semiconductor laser 1. The interval between the beam shaping lens 2 and the semiconductor laser 1 is adjusted so that they coincide with each other, and the direction of the numerical aperture (hereinafter referred to as the aspect ratio direction) of the beam shaping lens 2 is canceled to cancel the aspect ratio of the elliptical luminous flux. In addition, it is required to match the rotation direction with the optical axis of the beam shaping lens 2 as the rotation axis.

  In this beam shaping lens 2, the length of the elliptical lens indicated by the solid line 6 is set so that the pair of auxiliary lenses 9 are indicated on the flange portion 8 positioned on the outer periphery of the optical function portion 7 in the direction of the aspect ratio of the beam shaping lens. The symmetrical arrangement on the axis makes it possible to perform the adjustment operations related to the arrangement of the beam shaping lens 2 such as the optical axis adjustment, the interval adjustment, and the rotation adjustment described above without using the semiconductor laser 1, and the adjustment work is required. The time can be shortened.

  That is, when the beam shaping lens 2 is arranged on the base 3, the flat surface of the flange portion 8 and the emission surface of the semiconductor laser 1 or the wall surface of the base 3 are used to adjust the optical axis and the distance depending on the parallelism and the distance between them. Coarse adjustment is possible, and the auxiliary lens 9 indicating the direction of the aspect ratio of the beam shaping lens 2 is formed around the optical axis of the beam shaping lens 2 by forming a pair of auxiliary lenses 9 on the flange portion 8. The mark indicates the position in the rotation direction, and can be used for coarse adjustment in the rotation direction of the beam shaping lens 2.

  Further, fine adjustment can be performed on the auxiliary lens 9 by emitting an adjustment light beam 10 from an adjustment light source (not shown) different from that of the semiconductor laser 1 and observing its imaging state. it can. This fine adjustment in the arrangement of the beam shaping lens 2 is performed with respect to a pair of coarsely adjusted auxiliary lenses 9 as shown in FIGS. 4 and 5, and an adjustment light source different from the semiconductor laser 1 (not shown). The adjustment light beam 10 is emitted from the light source, and the shape, size and position of the focusing point of the adjustment light beam appearing on the wall surface of the base 3 along the emission end face of the semiconductor laser 1 are observed. The optical axis adjustment, the interval adjustment, and the rotation adjustment described in (1) can be positioned while accurately confirming, and thereafter, the adhesive can be fixed by using the UV adhesive 12 or the like. As a result, the time required for stabilizing the output and cooling of the semiconductor laser 1 in the adjustment work, which has been a conventional problem, can be greatly reduced.

  The optical axis adjustment of the beam shaping lens 2 is roughly divided into a lateral deviation in which the optical axes of the semiconductor laser 1 and the beam shaping lens 2 are parallel and shifted laterally, and an inclination deviation in which the optical axis is inclined. Is sufficient to align the focusing point of the adjustment beam, and the adjustment beam 10 is obliquely incident on the auxiliary lens 9 as shown in FIG. Since coma aberration and misalignment of the condensing position occur in the imaging state at the condensing point, fine adjustment can be performed while confirming these.

  In addition, since the rotation direction of the beam shaping lens 2 is also shifted in the rotation adjustment, it can be finely adjusted by correcting the position shift of the condensing point, similarly to the adjustment of the lateral shift described above.

  Further, regarding the adjustment of the distance between the semiconductor laser 1 and the beam shaping lens 2, as shown in FIG. 5, it is confirmed that the beam diameter of the adjustment light beam 10 collected by the auxiliary lens 9 becomes a predetermined size. Can be fine-tuned. In observing the beam diameter, a wall surface area on which the adjustment beam 10 is irradiated is provided on the base 3.

  In this case, if the distance between the beam shaping lens 2 and the semiconductor laser 1 is narrow or wide, the beam diameter at the condensing position of the adjustment light beam 10 is large, and conversely, the beam diameter at the condensing position is minimum. Since the focal length of the beam shaping lens 2 coincides with this distance at this time, the focal diameter is adjusted so as to be within an allowable range of optical characteristics required for the beam shaping lens 2 in the light source unit 4.

  As a method for confirming the image formation state of the beam shaping lens 2 in this way, a through-hole having a diameter that can be accepted as an image formation point of the adjustment light beam is formed on the wall surface of the base 3 that is an intended condensing position. By providing, fine adjustment can also be performed by confirming the protrusion of the adjustment light beam to the through hole.

  Moreover, as the light source for adjustment used for this fine adjustment, it is preferable to use a light source that emits a parallel constraint of visible light with a low power such as a He—Ne laser, because the semiconductor laser 1 and the beam shaping lens 2 are close to each other. Considering this, it is preferable that the adjustment light source is disposed on the exit surface side of the beam shaping lens 2 and the adjustment light beam 10 via the auxiliary lens 9 is condensed on the wall surface of the base 3.

  In order to provide the auxiliary lens 9 in the beam shaping lens 2, it is desirable to mold it by the same molding process as the incident surface and the exit surface which are the basic configuration of the beam shaping lens 2. This is because, as described above, the beam shaping lens 2 is such that the direction of the aspect ratio of each of the entrance surface and the exit surface is orthogonal, and the auxiliary lens 9 is used as a mark indicating the direction of this aspect ratio. This is because it is difficult to perform highly accurate positioning if molded separately.

  Therefore, as a method of integrally molding them, in the molding of the optical material 12 using the molding apparatus 11 as shown in FIG. 6, which is a general optical lens molding method, the molding apparatus 11 is a beam shaping lens. 2 is composed of an upper mold 13 that molds the incident surface, a lower mold 14 that molds the exit surface, and a body mold 15 that regulates sliding and molds the outer peripheral side surface of the beam shaping lens 2. By providing a molding surface (not shown) for forming the auxiliary lens 9 at a predetermined position of the mold 14, the auxiliary lens 9 is molded integrally with the optical function portion 7 on the entrance surface and the exit surface. Therefore, the positional accuracy of the auxiliary lens 9 with respect to the optical function unit 7 can be increased, and high reproducibility can be ensured in mass production.

  INDUSTRIAL APPLICABILITY The present invention has an effect of improving productivity in a light source unit in which a semiconductor laser and a beam shaping lens are integrated on a base, and is particularly useful in a light source unit for high output applications such as a laser beam projector. Become.

DESCRIPTION OF SYMBOLS 1 Semiconductor laser 2 Beam shaping lens 3 Base 4 Light source unit 7 Optical function part 8 Flange part 9 Auxiliary lens

Claims (4)

A base, a semiconductor laser disposed on the base, and a beam shaping lens that is disposed on the base and adjusts an aspect ratio of an elliptical light beam emitted from the semiconductor laser, and the beam shaping lens includes: An optical function unit for adjusting an aspect ratio and a flange portion provided on an outer periphery of the optical function unit, and an auxiliary lens for aligning the beam shaping lens is provided on the flange portion. . A base, a semiconductor laser disposed on the base, and a beam shaping lens that is disposed on the base and adjusts an aspect ratio of an elliptical light beam emitted from the semiconductor laser. An optical function unit for adjusting the aspect ratio, and a flange unit provided on an outer periphery of the optical function unit, and the flange unit includes an auxiliary lens for alignment of the beam shaping lens. A method of manufacturing a light source unit, comprising: adjusting light by emitting an adjustment light beam from an adjustment light source different from the semiconductor laser to the auxiliary lens and confirming an imaging state thereof. 3. The method of manufacturing a light source unit according to claim 2, wherein the adjustment light beam is emitted to the exit surface side of the beam shaping lens. A beam shaping lens for adjusting an aspect ratio of an elliptical light beam emitted from a semiconductor laser, wherein the beam shaping lens includes an optical function part for adjusting the aspect ratio and a flange part provided on an outer periphery of the optical function part. And a beam shaping lens provided with an auxiliary lens for positioning the beam shaping lens on the flange portion.

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