JPH0440184Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a support device for a light modulation element, and particularly to a support device for a light modulation element suitable for use as an acousto-optic device.

[Prior Art] In an acousto-optic device, a laser beam is incident on an ultrasonic propagation medium that propagates an ultrasonic wave, and the incident light is diffracted by the ultrasonic wave to perform optical modulation. Conventionally, a light modulation element that performs such light modulation has been fixed at a predetermined position and has no particular mechanism for adjusting its position.

[Problems to be solved by the invention] Therefore, as shown in FIG.
The attachment position of the piezoelectric body 52 attached to the end face of the light modulating element 51 may be misaligned, or the optical axis 5 of the incident light of the entire light modulating element 51 may be
If the position relative to 3 is shifted, the optical axis 53 of the incident light will be deviated from the ultrasound propagation region 54, resulting in a disadvantage that the diffraction efficiency (modulation efficiency) will be significantly degraded. Furthermore, in order to return the incident light optical axis 53 into the ultrasonic propagation region 54, there is a drawback that the relative positional relationship between the laser light source and the entire acousto-optic device must be corrected.

As shown in FIG. 5, when graphed with the vertical position of the optical axis of the incident light on the horizontal axis and the diffraction efficiency of the incident light on the vertical axis, in order to obtain a predetermined diffraction efficiency, It can be seen that the optical axis of the incident light is within a certain value range, and particularly preferably within the width L of the piezoelectric body 52. Therefore, if the width L of the piezoelectric body 52 is increased, a large voltage must be applied to the piezoelectric body 52, resulting in an increase in power consumption.

The present invention was developed to eliminate these conventional drawbacks, and is equipped with a mechanism that allows the relative position of the light modulation element to the incident light to be easily adjusted in order to obtain maximum diffraction efficiency with low power consumption. An object of the present invention is to provide a support device for a light modulation element.

[Means for Solving the Problems] The support device for a light modulation element of the present invention diffracts a laser beam incident on an ultrasonic propagation medium using an ultrasonic wave from a piezoelectric material attached to one end surface of the medium, and modulates the light. The light modulator is placed in close contact with the entire bottom surface of the light modulator, which is one of the two opposing surfaces other than the laser light input/output surface and the surface to which the piezoelectric material is attached. A support stand consisting of an upper support stand whose lower surface is a slope, and a lower support stand installed under the upper support stand whose upper surface is a slope, the slope of the lower surface of the upper support stand and the upper surface of the lower support stand. a support base that moves the light modulation element in the vertical direction by converting the horizontal movement of the lower support base into the vertical movement of the upper support base; A pressing member that presses a surface opposite to the bottom surface of the upper light modulation element from above, and a housing that locks the pressing member and stores the support base in a recess provided in the bottom surface of the housing. It is characterized in that the support position of the light modulation element can be adjusted at least in the vertical direction.

The present invention will be explained in more detail below with reference to the drawings.

FIG. 6 is a sectional view showing a comparative example. In the figure, the light modulation element 11 is placed on a support base 12. The support stand 12 can freely slide up and down along the column 13. The upper surface of the light modulation element 11 is pressed with a screw 15 via a member 14. The screw 15 is screwed into the inner housing 16. A spring 17 is provided between the bottom surface of the inner casing 16 and the lower surface of the support base 12, and provides an upward elastic force to the support base 12. Inner housing 16
An outer casing 18 is provided on the outside of the casing 18, and a screw 19 is threaded into the side surface of the outer casing 18 so as to apply a horizontal pressing force to the inner casing 16. A spring 20 is provided between the inner surface of the outer casing 18 on the opposite side of the screw 19 and the outer surface of the inner casing 16, and applies an elastic force in the opposite direction to the pressing force of the screw 19 to the inner casing 16. It is attached to the outer surface of the. Since the light modulation element 11 is fixed by a spring 17 on the lower surface of the support base, depending on the elastic force of the spring 17, external vibrations may cause troubles such as displacement of the position. There is a problem with the stability of the fixation.

FIG. 1 is a partial sectional view showing one implementation row of the present invention. In this example, the support base is in close contact with the entire bottom surface of the light modulation element 11, which is one of the two opposing surfaces other than the laser light input/output surface and the surface to which the piezoelectric material is attached. an upper support stand 21 on which is placed an upper support stand 21 whose lower surface is formed as a slope;
1, and a lower support 22 whose upper surface is formed into a slope. The lower support 22 is applied with a horizontal pressing force by a screw 23 screwed into the side surface of the inner casing 16, and slides horizontally in a recess 16a provided on the bottom surface of the inner casing 16. do. This horizontal movement of the lower support table is converted into a vertical movement of the upper support table 21 due to the mutual sliding movement of the slope with the upper support table. Note that the upper support base 21 is located in the recess 16a.
It moves up and down along the inner surface of the In this example, the positioning in the vertical direction is performed by the screws 15, which are pressing members that press the supports 21 and 22 and the opposite surface of the bottom surface of the light modulation element 11 from above, so that the position of the light modulation element 11 can be set more firmly. can be fixed. The rest of the configuration is the same as the comparative example shown in FIG. 6, so the explanation thereof will be omitted.

FIG. 2 is a partial sectional view showing a second example of the present invention, in which the horizontal position adjustment is omitted and only the vertical position adjustment mechanism is left. Therefore, the housing only needs to have the inner housing 16, and the outer housing 18 can be omitted.If horizontal positional accuracy is not a big problem, production costs can be reduced by configuring as in this example. can be kept low. The rest of the configuration is the same as the example shown in FIG. 1, so a description thereof will be omitted.

FIG. 3 is a partial sectional view showing a third example of the present invention. In this example, a spring 41 and a column 42 are provided in place of the screw 15 in the example of FIG. 2 to provide a vertical support mechanism. This is a more simplified version. In this example, the vertical position can be adjusted more easily.
Note that the other configurations are the same as the example shown in FIG. 2, so the explanation thereof will be omitted.

[Function] In the comparative example shown in FIG. 6, by adjusting the screw 15, the vertical position of the light modulating element 11 can be adjusted by combining the downward pressing force of the screw 15 and the upward urging force of the spring 17. I'm making adjustments.
Similarly, the horizontal position adjustment can be done using the screw 19.
It is adjusted by the action of the spring 20.

In the example shown in FIG. 1, the horizontal position adjustment is performed in the same manner as in the comparative example shown in FIG. When adjusting the position of the light modulation element 11 upward, loosen the screw 15 to provide some play in the upward position.
By screwing in the screw 23, the lower support stand 22 is moved to the right in the figure, the upper support stand 21 is moved upward, and the light modulation element 11 is set at an appropriate position. This is done by pressing the light modulating element 11 from above to fix its position. To correct the position of the light modulation element 11 downward, loosen the screw 23 to provide some play to the left in the figure, then screw in the screw 15 to press the light modulation element 11 downward and move the lower part of the light modulation element 11 downward by the lower slope of the upper support base 21. Move the support stand 22 to the left in the figure and set the light modulation element 11 at an appropriate position, then tighten the screws 23.
Screw in the lower support stand 22 and upper support stand 21.
The light modulation element 11 is pressed through it to fix its position.

In the example shown in FIG. 2, vertical position adjustment is performed in the same way as in the example shown in FIG.

In the example shown in FIG. 3, since the upper pressing member is composed of the spring 41, the support column 42, and the member 14, the vertical position of the light modulation element 11 is adjusted by the balance between the pressing force of the screw 23 and the urging force of the spring 41. Adjustments can be made easily.

[Effects of the invention] In the light modulation element support device of the present invention, a mechanism that can easily and stably adjust the support position of the light modulation element is provided, so that the position of the optical axis of the light incident on the light modulation element can be adjusted easily. The deviation can be adjusted extremely easily,
In addition, since there is no need to increase the width of the piezoelectric body, the light modulation element can be driven with low power consumption, and there is no need to increase the precision of the position where the piezoelectric body is attached to the light modulation element. The piezoelectric body attachment process can be simplified. Furthermore, since the entire bottom surface of the light modulation element is in close contact with the support base, it also has the effect that heat generated during driving can be dissipated more efficiently.

[Brief explanation of the drawing]

Figures 1 to 3 are the first to third figures of the present invention.
FIG. 4 is a side view showing the positional relationship between the light modulation element and the optical axis of the incident light, and FIG. 5 shows the relationship between the vertical position of the optical axis of the incident light and the diffraction efficiency. FIG. 6 is a partial sectional view showing a comparative example. 11... Light modulation element, 12, 21, 22... Support stand, 13, 42... Support column, 14... Member, 1
5, 19, 23... Screw, 16, 18... Housing,
17, 20, 41...Spring.

Claims (1)

[Utility Model Claims] (1) An optical modulation element which performs optical modulation by diffracting laser light incident on an ultrasonic propagation medium using ultrasonic waves from a piezoelectric body attached to one end surface of the optical modulation element, said optical modulation element being placed in close contact with the entire bottom surface, which is one of two opposing surfaces other than the laser light entrance/exit surface and the surface to which the piezoelectric body is attached, and whose underside is made sloped, and a lower support stand which is placed below the upper support stand and whose upper side is made sloped, said support stand being configured so that the sloped surface of the underside of the upper support stand and the sloped surface of the upper support stand can slide relative to each other, and which moves the optical modulation element up and down by converting the horizontal movement of the lower support stand into the vertical movement of the upper support stand;
A support device for an optical modulation element, comprising a pressing member for pressing from above the surface opposite to the bottom surface of the optical modulation element on the support base, and a housing for engaging the pressing member and storing the support base in a recess provided in its internal bottom surface, and configured so that the support position of the optical modulation element can be adjusted at least in the vertical direction. (2) A support device for an optical modulation element as set forth in utility model claim 1, in which the housing is constructed of two layers, an inner housing and an outer housing, and the inner housing can be moved horizontally within the outer housing. (3) A support device for an optical modulation element as set forth in utility model claim 1 or 2, in which the pressing member is a screw. (4) A support device for an optical modulation element as set forth in utility model claim 1 or 2, in which the pressing member is an elastic member.