JPH01303403A - United type beam shaping optical system - Google Patents

Abstract

PURPOSE:To facilitate the alignment between a light source and a beam converting prism optical system, to decrease the number of components, and to improve the assembly accuracy by enabling an air layer to serves as a prism and uniting plural prism operations as to an anamorphic type beam shaping optical system. CONSTITUTION:For example, luminous flux 1 is mode incident on a glass block 2 and enters a hollowed air layer 3. Then the luminous flux enters the glass block again slantingly and is refracted and narrowed down to pass a glass raw material. Then the luminous flux enters a 2nd hollowed air layer 4 again and is made incident slantingly on an opposite surface and refracted, and further the beam luminous flux is narrowed down and projected from the glass block 2 as narrowed-down beam luminous flux 5. Thus, individual prisms which are used for beam conversion are united. Consequently, the alignment between the light source and beam converting prism optical system is facilitated, the number of components is decreased, the assembly accuracy is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a beam shaping optical system that can freely change the vertical/horizontal ratio of the intensity distribution of a highly directional beam such as a laser beam.

(Prior Art) Conventionally, the cross-sectional intensity distribution of a laser beam is isotropic in the case of a gas laser and anisotropic in the case of a semiconductor laser. Alternatively, a prism or a set of prisms was commonly used as a shaping optical system for converting anisotropy into anisotropy with different vertical/horizontal ratios.

[Problem to be solved by the invention]

However, in the above-mentioned conventional technology, one or more prisms are arranged separately, so when implementing them, there are many alignment points, the number of process control points increases, the cost of the assembled optical system is high, and the mechanical There were many problems, including loss of placement accuracy over time due to thermal vibration.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, to realize a beam conversion optical system that greatly facilitates alignment between a laser beam light source and a beam conversion prism optical system, reduces the number of parts, and improves assembly accuracy. It is to be.

[Means to solve the problem]

The above object is achieved by integrating the separate prisms used for beam conversion. In other words, conventional prisms are made by polishing a glass element so that the cross section is triangular, but in the present invention, on the contrary, the prism is formed by hollowing out the glass material so that the cross section is triangular or trapezoidal. do.

In other words, by forming a single or multiple triangular prism-shaped cavities in one glass block, a negative prism is created, and each time the beam passes through this, the beam diameter is anamorphically expanded, or It has a reduction function.

[Effect]

That is, in FIG. 1(a), a light beam 1 enters a glass block 2 and enters a hollowed-out air layer 3. After that, it enters the glass block again at an angle and is refracted,
The beam bundle is narrowed and passes through the glass material. Then, it enters the second hollowed-out air layer 4 again, enters the opposing surface obliquely, undergoes refraction, and is further narrowed to be emitted as a narrow beam 5 outside the glass block.

The above process is an explanation of the situation in which the beam diameter is reduced, and as shown in the plan view (b), a beam with an isotropic intensity distribution is beam-shaped into a flat beam 5.

It goes without saying that the flat beam 5 can be beam-shaped into the isotropic beam 1 by retracing this beam process from the exit side.

Furthermore, when the beam diameter is narrower than that in FIG. 1(b) with respect to the cross section in FIG. 1(a) (FIG. 1(C)), the vertically long beam 1' incident from the left is It is also possible to transform it into an isotropic beam 5', and considering the incidence from the right side, it can be considered that it has the function of converting an isotropic beam into a vertically long beam 1'.

〔Example〕

An embodiment of the present invention is shown in FIG. 2 below. Namely.

In this embodiment, since the incident beam 6 and the exit beam 12 are on the same optical axis 7, there is an advantage that no translational shift of the beam occurs due to beam shaping.

This is because the beam refracted by the air layer 8 is totally reflected by the bottom surface 10 of the glass block 9, the beam is reflected back and enters the air layer 11, and is refracted again to emit a beam 12.
This is because.

FIG. 3 shows a second embodiment of the invention. That is, when it is desired to increase the beam expansion or reduction ratio, the number of prisms shown in FIG. 1 or 2 is increased to obtain a beam with a larger or smaller diameter. In this example, the incident beam 13 and the exit beam 14 can be shaped without parallel movement of the beams.

Further, according to the present invention, for example, as shown in FIG. 4, a beam from a semiconductor laser 15 having an anisotropic intensity distribution is collimated by a collimator 16, and then introduced into a beam shaper 17 as in the above embodiment. The surface to be scanned (optical disk, rotating drum, etc.) 1 is then scanned by the focus lens 18.
It becomes possible to irradiate a spot of an arbitrary shape onto 9.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to integrate multiple prism functions, and for example, it is possible to shape a semiconductor laser beam having an intensity distribution with a different vertical-to-width ratio, or to Furthermore, it can also be used for shaping a phased array type semiconductor laser beam, which is significantly different. Conventionally, seven alignments of individual prisms were arranged on the optical system, one each, but this has been unified into one block, reducing the number of alignment steps, and reducing mechanical or thermal alignment between prisms. You can discover the effects of scattering, such as protection from vibration.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view and a front view of a prism for explaining the principle of the present invention, FIGS. 2 and 3 are a side sectional view and a plan view of a prism according to an embodiment of the present invention, and FIG. FIG. 2 is a schematic diagram of a light spot irradiation optical system according to an embodiment of the present invention. 1... Luminous flux, 2... Glass block, 3, 4...
A cavity forming a prism. \, -” Fig. 1 (3, 15 \ (Fig. 33 Fig. 4)

Claims (1)

[Claims] 1. An integrated beam shaping optical system characterized in that an air layer has a prism effect in an anamorphic beam shaping optical system that converts the aspect ratio of the beam intensity distribution.