JPH065989A - Case for laser generation device - Google Patents

Abstract

PURPOSE:To let only light with desired wavelength pass to the outside, and to prevent return of returning light into a resonator of the laser generation device, by sealing a laser generation device in a case to the open air with a blocking member, and by mounting obliquely an optical element having optical wavelength selectivity on a window provided on the blocking member. CONSTITUTION:A laser generation part and a mirror which constitute a laser generation device are housed in the open space inside of a case body 11. A cover 12 serves as an interrupter between inside of the case and the open air. The cover 12 is provided with a window which makes pass the output light coming from the laser generation device to the outside. The surface of the window 13 serves as a reflection preventing film against the desired light by using glass, quartz and/or crystal, and it serves as an interference filter against other light, thereby an optical element having optional wavelength is formed. The window 13 is mounted on the cover 12 by using a supporter 14 in such a way that the angle is inclined by 0 to the optical axis of output light from the laser generation device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser generator casing suitable for constituting a laser generator.

[0002]

2. Description of the Related Art For example, in an optical disk reproducing apparatus,
An optical pickup device irradiates a recording surface of an optical disk with a light beam, guides reflected light from the optical surface to a photodetector, and reads data and the like recorded on the recording surface.
As laser light to the optical pickup device, a laser medium from a semiconductor laser is used as excitation light to irradiate a laser medium such as a solid-state laser to excite the solid-state laser to generate a fundamental wave laser light having a wavelength of 1064 nm. The fundamental wave laser light is resonated in a pair of reflecting mirrors, the wavelength is converted by a non-linear optical crystal element to generate a second harmonic (SHG), and there is a laser beam emitted as a second harmonic laser light.

For example, a laser generator for generating the above second harmonic laser light has a resonance structure composed of a pair of reflecting mirrors and efficiently performs wavelength conversion by utilizing a high power density inside the resonator. It must be kept in an enclosure that is sealed from the atmosphere.

A schematic structure of a conventional casing for a laser generator is shown in FIGS. In FIG. 3, a housing main body 51 that constitutes the housing 50 and a lid 52 made up of a closing member that closes the housing main body 51 are in an open state, and a back surface 52b of the lid 52 is on the upper side. It is the figure shown. In addition, FIG.
FIG. 6 is a cross-sectional view of the casing 50 in a state where the opening of the casing main body 51 is closed by the lid 52, taken in the direction of a dashed line LR.

In FIGS. 3 and 4, the lid 52 is provided with a hole through which a light beam from the laser generator passes, and a hatched window portion 53 made of glass or the like is adhered to this hole. The window portion 53 is fused and covered with a cover glass 54. The window 53 has a lower end surface 53b and an upper end surface 53.
It is attached to the lid body 52 so that a is parallel to the back surface 52b and the front surface 52a of the lid body 52.

Further, inside the housing 50, a laser generator 61 composed of a laser medium arranged to have a resonance structure, a semiconductor laser, a pair of reflecting mirrors, a nonlinear optical crystal element, and the like, and the laser generator. A mirror 62 for reflecting the light flux from the portion 61 at a right angle for the purpose of sending it to the optical system of the optical pickup device is housed. Therefore, the optical axis of the light flux from the mirror portion 62 is perpendicular to the lower end surface 53b of the window portion 53.

[0007]

By the way, in the conventional laser generator housing 50, since the window 53 is simply made of glass or the like, the semiconductor housed inside as a part of the laser generator 61. The excitation light from the laser and the fundamental light from the laser medium have also been emitted together with the desired second harmonic light. These excitation light and fundamental light, for example, enter the optical pickup device as light other than the desired light (second harmonic laser light), and cause noise in the reproduction signal and servo signal obtained from the optical pickup device. Will be generated.

The fact that the optical axis of the light flux from the mirror 62 is perpendicular to the lower end surface 53b of the window portion 53 means that unnecessary light (stray light) from the optical pickup device toward the laser generator. When the stray light returns, the stray light is bent at a right angle in the direction of the laser generating section 61 by the mirror 62, so that the resonance part in the laser generating section 61 is affected, the oscillation becomes unstable, and the optical output is Fluctuates,
The vertical and horizontal modes become unstable, and noise gets on the output light.

Therefore, the present invention has been made in view of the above circumstances, and it is possible to obtain a good reproduction signal and a servo signal in an optical pickup device as well as to seal the inside with respect to the outside air. It is an object of the present invention to provide a housing for a laser generator that can provide a more stable laser output.

[0010]

A laser generator casing according to the present invention is a casing for accommodating a laser generator, the casing main body having an opening, and an output from the laser generator. The above-mentioned problem is characterized in that it has a closing member that closes the casing main body by providing a window portion that allows light to pass to the outside, and that an optical element having wavelength selectivity is obliquely attached to the window portion. To do.

Here, the optical element having wavelength selectivity attached to the window portion is made of a material such as glass, quartz, or crystal, and its surface is an antireflection film for desired light. , It is an interference filter for other light.

Then, the optical element is attached or fused and attached to the closing member using a supporting member so as to be slightly inclined with respect to a reference plane perpendicular to the optical axis.

[0013]

The closing member hermetically seals the laser generator inside the housing against the outside air, and the optical element having wavelength selectivity is obliquely attached to the window provided in the closing member, so that only the light of the desired wavelength can be obtained. To the outside of the laser generator so that the return light does not return to the resonator of the laser generator.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a laser generator housing according to the present invention will be described below with reference to the drawings. In FIG. 1, a housing body 11 that constitutes a housing 10 for a laser generator and a lid 12 made of a closing member that closes the housing body 11 are opened, and a back surface 12b of the lid 12 is shown. FIG. Further, FIG. 2 is a cross-sectional view of the laser generator housing 10 in a state in which the opening of the housing body 11 is closed by the lid 12, taken along the dashed line LR.

The laser generator housing 10 of this embodiment is
As shown in FIG. 1 and FIG. 2, the housing main body 11 is provided. The housing body 11 forms an outer shell of the laser generator, and is formed with a space on the inner side. In the space on the inner side of the housing body 11, a laser generator 21, which constitutes the above laser generator,
A mirror 22 and the like are stored.

An opening is formed in the housing body 11. This opening is a through hole formed in a rectangular shape.

The housing 10 for the laser generator is provided.
Has a lid 12 made of a closing member adapted to close the opening. The lid 12 has a rectangular shape that covers the upper portion of the casing body 11, and has two screw recesses on each side in the longitudinal direction. Further, the lid 12 has a rectangular protrusion corresponding to the opening, and the recesses at each of the two positions are formed by screws.
It is fixed so as to fit into the receiving hole of the housing body 11, and blocks the inside of the housing from the outside air.

Here, as shown in FIG. 2, the lid 12 has a laser generator 21 and a mirror 22 housed in a housing.
A window portion 13 for passing the output light from the laser generator to the outside is provided. The window portion 13 is made of a material such as glass, quartz, or crystal, and its surface is an antireflection film for desired light and an interference filter for other light. It is formed by an optical element having excellent wavelength selectivity. The window portion 13 is attached to the lid body 12 by using a support portion 14 so as to be inclined by an angle θ with respect to a reference plane that is perpendicular to the optical axis of the output light from the laser generator.

Therefore, in the present embodiment, by using the window portion 13 as an optical element having wavelength selectivity, desired output light (second harmonic) generated by the laser generating portion 21 and bent at a right angle by the mirror 22 is obtained. Only the wave) is emitted to the optical system of the optical pickup device, for example.

Further, by mounting the window portion 13 with a slight inclination with respect to the reference plane which is perpendicular to the optical axis of the optical pickup device, unnecessary return light from the optical pickup device is reflected in the resonator of the laser generator. You can avoid returning.

Further, by bonding or fusing the window 13 to the lid 12, the laser generator inside the housing can be sealed so as not to be exposed to the outside air.

The casing for the laser generator according to the present invention is not limited to the above embodiment, and the shape of the casing is not limited to the above embodiment.

[0023]

The housing for the laser generator according to the present invention comprises:
The blocking member hermetically seals the laser generator inside the housing against the outside air, and the window provided on the blocking member is obliquely attached to the window, so that only the light of the desired wavelength is exposed to the outside. It is possible to allow the light to pass therethrough and prevent the returned light from returning to the resonator of the laser generator. Therefore, for example, when applied to an optical pickup device, a good reproduction signal and a servo signal can be obtained, and a more stable laser output can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of an embodiment of a laser generator casing according to the present invention.

FIG. 2 is a sectional view of the present embodiment.

FIG. 3 is a perspective view showing a schematic configuration of a conventional laser generator casing.

FIG. 4 is a cross-sectional view of a conventional laser generator housing.

[Explanation of symbols]

 10 ... Laser generator housing 11 ... Housing body 12 ... Lid 13 ... Window 21 ... Laser generator 22 ... ···mirror

Claims (1)

[Claims] 1. A housing for accommodating a laser generator, the housing main body having an opening, and a window portion for passing the output light from the laser generator to the outside to close the housing main body. A laser generator casing, comprising: an optical element having a wavelength selectivity is obliquely attached to the window portion.