JPS6327814A - Multibeam optical modulating element - Google Patents

Abstract

PURPOSE:To eliminate the need for a complicate mutual position adjustment between an acoustooptic medium and a beam splitter and to improve the production efficiency by constituting the acoustooptic medium and beam splitter in one body. CONSTITUTION:The laser beam incidence end surface of the acoustooptic medium 1 is slanted to a laser beam by an angle required by the beam splitter 6 to split the laser beam into plural beams. The incidence end surface of this acoustooptic medium 1 is coated with an adhesive across a reflection preventive film 4 to form an adhesive layer 5. The surface of the translucent film 7 of the beam splitter 7 is also coated with an adhesive as well and adhered to the incidence end surface of the acoustooptic medium 1 and fixed so that the plural projection beams 12 divided by the beam splitters 6 pass positions corresponding to plural electrodes 2 applied with modulating signals. Thus, the acoustooptic medium and beam splitter are formed in one body, so neither a mechanism nor a process for adjusting their mutual positions is required and the production efficiency is improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a multi-beam optical modulator.

[Background Art] In recent years, with the progress of technology related to optoelectronics, optical modulation elements that modulate laser beams with acoustic signals have been widely used. Especially in the field of laser engraving, it is necessary to expose high-definition patterns in a short time.
Multibeam light modulators that modulate multiple laser beams with a single acousto-optic device have been developed and used in conjunction with beam splitters. In this case, as shown in the front view in FIG. 3, the acousto-optic medium 1 and the beam splitter 6 of the acousto-optic element are assembled to the pedestal as independent parts,
It was usual to adjust their mutual positional relationship.

In the figure, the acousto-optic element has a piezoelectric element 3 attached to the surface of the acousto-optic medium 1 via a common electrode (not shown), and an electric wire 8i2 for applying a plurality of electrical signals to H of the piezoelectric element 3. It is configured by providing multiple. Further, an antireflection film 4 is formed on the incident surface and the exit surface of the plurality of laser beams of the acousto-optic medium 1 by a method such as vapor deposition. Furthermore, the beam splitter 6 has a total reflection film 8 on one surface thereof.
is formed, and a semi-transparent film 7 is formed on the other surface. Further, an anti-reflection film 9 is formed on one end of the surface on the side where the total reflection film 8 is formed in order to guide the incident beam 11 into the beam splitter 6, and an anti-reflection film 9 is formed on one end of the surface on the side where the semi-transmission film 7 is formed. On one end surface of the surface, an incident beam 1 that has been reflected many times in the beam splitter 6 and formed a plurality of outgoing beams 12 is shown.
A total transmission film 10 is formed so that the light beam 1 does not repeat reflection in the beam splitter 6 any more.

The incident beam 11 such as a laser beam is transmitted from the anti-reflection film 9 of the beam splitter formed in this manner.
The beam enters the beam splitter 6 at a predetermined angle, and a part of it passes through the beam splitter 6 as it is through the semi-transparent film 7 and exits, becoming an output beam 12. It is reflected inside, is further reflected by the total reflection film 8, and a part of it is reflected again by the semi-transmission film 7 as an output beam 12.
The remainder is reflected in the beam splitter 6 again. By repeating this operation, the incident beam 11 entering the beam splitter 6 becomes a plurality of parallel outgoing beams 12.

This output beam 12 enters from the light incident end face of the acousto-optic medium l through the anti-reflection film 4, is modulated by the acoustic signal propagating in the acousto-optic medium l, and becomes a modulated output beam 12, The light is emitted from the output end face of the acousto-optic medium 1 via the antireflection film 4 .

Since a plurality of electrodes 2 are formed on the surface of the acousto-optic medium 1, by applying a plurality of electrical signals to the electrodes 2, the plurality of laser beams emitted from the beam splitter 6 can be respectively modulated. This is possible.

[Problems to be Solved by the Invention] In the conventional multi-beam optical modulation device, as described above, the acousto-optic device and the beam splitter 6 are each fixed on a pedestal as independent components, and their relative positions are fixed. This required complicated positional adjustments such as setting the inclination angle of the beam splitter 6 with respect to the incident light and setting the mutual positional relationship with the acousto-optic medium l, resulting in poor production efficiency. there were.

The present invention has been made to eliminate these drawbacks of conventional multi-dome optical modulators, and by integrally configuring an acousto-optic medium and a beam splitter, it is possible to eliminate complicated mutual positioning. The purpose of the present invention is to provide a multi-beam optical modulator that does not require adjustment and has high production efficiency.

[Means for Solving the Problem] The multi-beam light modulation element according to the present invention includes an acousto-optic medium that modulates a plurality of light beams with a plurality of acoustic signals, and an acousto-optic medium that divides incident light into a plurality of light beams. A multi-beam optical modulation element having a beam splitter for supplying a plurality of beams to a plurality of beams, the beam splitter being fixed to one surface of the acousto-optic medium.

[Function] In the multi-beam optical modulator of the present invention, since the beam splitter is fixed to one surface of the acousto-optic medium,
This eliminates the need for mutual positional adjustment between the acousto-optic medium and the beam splitter, resulting in high production efficiency.

[Example] The present invention will be described in detail below with reference to one drawing.

Components that are the same as those in the conventional example shown in FIG. 3 are designated by the same reference numerals, and their explanations will be omitted.

FIG. 1 is a front view showing one embodiment of the present invention. In FIG. angle relative to the laser beam. An adhesive is applied to the incident end face of the acousto-optic medium 1 via an antireflection film 4 to form an adhesive layer 5. An adhesive is similarly applied to the surface of the semi-transparent film 7 of the beam tin 1 jitter 6, and it is bonded to the incident end face of the acousto-optic medium 1, and as shown in the figure, a plurality of output beams are divided by the beam splitter 6. The beam 12 is adhesively fixed so as to pass through positions corresponding to the plurality of electrodes 2 to which a plurality of modulation signals are applied.

FIG. 2 is a front view showing another embodiment of the present invention. In FIG. 0, the electrode 2 provided on the surface of the acousto-optic medium 1 is
In this embodiment, the light incident end face of the acousto-optic medium l is formed by being inclined by an angle necessary to split the incident beam 11 entering the beam splitter 6 into a plurality of outgoing beams 12. In any of the embodiments shown in FIGS. 1 and 2, in which 0 or more are arranged in an upward row on the light emitting end face of the beam splitter 6, the incident beam 11 of the laser beam, etc., enters the beam splitter 6.

The light enters the beam splitter 6 through the anti-reflection film 9 of the beam splitter 6, and the semi-transparent film 7 of the beam splitter 6 enters the beam splitter 6.
A part of the beam is emitted as it is from the beam splitter 6, enters the acousto-optic medium l, is modulated by the acoustic signal propagating in the blind π optical medium l, is emitted from the acousto-optic medium 1, and becomes an output beam. It becomes 12.

Further, a part of the incident beam 11 is reflected by the semi-transparent film 7 into the beam splitter 6, and totally reflected by the total reflection film 8,
Once again, a part of the light is emitted from the beam splitter 6 by the semi-transparent film 7, enters the acousto-optic medium 1, is modulated by a modulation signal, and becomes an emitted beam 12.

When the multi-beam light modulation element of the present invention is used in a laser plate making machine or the like, the modulated output beam 12 is exposed onto a photosensitive material or the like to perform laser writing.

It should be noted that the multi-beam optical modulation element of the present invention is not limited to the above embodiments, and for example, the beam splitter 6 may be formed as a thin film on the surface of the acousto-optic medium l by a method such as vapor deposition. .

[Effects of the Invention] In the multi-beam optical modulation device of the present invention, since the acoustic π optical medium and the beam splitter etc. are integrally formed, there is no need for a mechanism or process for adjusting the mutual position t, resulting in extremely high production efficiency. It has a high value.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of the present invention, FIG. 2 is a front view showing another embodiment of the present invention, and FIG. 3 is a front view of a conventional example.
It is a Ti diagram. l: acousto-optic medium, 2: electrode, 3: piezoelectric element, 4, 9: antireflection film, 5: TA layer, 6: beam splitter, 7 semi-transparent film,
8: Total reflection film, 10: Total transmission film, 11: Incident beam, 12: Output beam

Claims (2)

[Claims] (1) In a multi-beam light modulation element having an acousto-optic medium that modulates a plurality of light beams with a plurality of acoustic signals and a beam splitter that splits incident light into a plurality of light beams and supplies them to the acousto-optic medium, the beam A multi-beam optical modulation element comprising a splitter fixed to one surface of the acousto-optic medium. (2) The beam splitter mounting surface of the acousto-optic medium is
2. The multi-beam light modulation element according to claim 1, wherein the multi-beam light modulation element is inclined with respect to the incident light by an angle necessary to split the incident light to the beam splitter.