JPH05217836A - Member and method for alignment of micro optical element - Google Patents

Abstract

PURPOSE:To align an optical system using a micro optical element at low costs and simply. CONSTITUTION:An alignment member 20 for the micro optical element is composed of a plane boardlike glass substrate 20a and of a silicon substrate 20ab bonded to the glass substrate. The silicon substrate is provided with a plurality of hole parts 21 to 27 which have been formed by an anisotropic etching and which through the silicon substrate. The alignment member is prepared. Micro optical elements are inserted into the plurality of hole parts in the member 20, and they are bonded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment member used for alignment of a micro optical element in an optical system using the micro optical element and an alignment method using the member.

[0002]

2. Description of the Related Art In order to meet the specifications required for an optical system, it is necessary to align optical elements such as lenses, mirrors and prisms used in the optical system at predetermined optical positions within an allowable error. You will need it. However, when the tolerance of alignment is very small, conventionally, a skilled worker manually aligns each optical element, or a dedicated alignment mechanism is provided for each optical element, and this mechanism is used. Either the position of the optical element is adjusted.

[0003]

However, the conventional manual alignment requires a long time by a skilled worker, and the precision alignment mechanism is expensive, so that the cost required for the alignment of the optical system is low. It was a serious issue. Further, in the case of an optical system using micro optical elements, the size of each micro optical element is about several millimeters, and the size of the entire optical system is about several centimeters. Therefore, it is difficult to provide a precise mechanical alignment mechanism for each micro optical element from the viewpoint of installation space.

An object of the present invention is to solve the above problems.

[0005]

To achieve the above object, the present invention comprises a flat glass substrate and a flat silicon substrate bonded to the glass substrate, and the silicon substrate is formed by anisotropic etching. A micro-optical element alignment member having a plurality of holes penetrating the silicon substrate was prepared, and the micro-optical element was inserted into the plurality of holes of the member and bonded.

[0006]

According to the present invention, the alignment of the optical system is performed by inserting and adhering each micro optical element into the alignment hole provided in the micro optical element alignment member. Since the alignment hole provided in the silicon substrate is formed by using the photolithography technique and the anisotropic etching technique, its position, size and shape can be accurately controlled. Therefore, the alignment of the entire optical system can be accurately performed only by inserting and adhering each micro optical element into the alignment hole of the silicon substrate bonded to the glass substrate.

Particularly, as a silicon substrate, the plane orientation is (10
The use of 0) makes it possible to accurately control the shape of the hole for alignment during etching.
If a glass substrate containing sodium is used as the glass substrate, the glass substrate and the silicon substrate can be joined by the anodic bonding method. Hereinafter, the present invention will be described in more detail with reference to examples.

[0008]

1 is a schematic view showing an embodiment of the present invention. 1A is a plan view, and FIG. 1B is a sectional view taken along the line AA of FIG. Micro optical element alignment member 2 of this embodiment
0 is composed of a glass substrate 20a and a silicon substrate 20b bonded to the glass substrate 20a. This member 20 has alignment hole portions 21 to 27 of the micro optical element formed so as to penetrate the silicon substrate 20b by anisotropic etching of silicon.

Next, a method of forming a hole for alignment will be described with reference to FIG. As shown in FIG. 3A, first, silicon dioxide films 31 and 32 are formed on the front and back surfaces of a silicon substrate 30 having a plane orientation of (100). This silicon dioxide film is formed by oxidizing the silicon substrate 30 in an electric furnace in an oxygen or water vapor atmosphere at a high temperature of about 1000 ° C. It should be noted that the films 31 and 32 are not limited to the silicon dioxide film, and may be, for example, silicon nitride formed by the low pressure vapor phase growth method.

Next, a photoresist 33 is applied to the silicon dioxide film 31, and a pattern of alignment hole portions of the micro optical element is formed in the photoresist 33 by using a well-known photolithography technique. The position, size and shape of the alignment hole portion of the micro optical element are determined by the photomask used, and therefore can be controlled very accurately. Then, the silicon dioxide film 31 is etched using the photoresist 33 as a mask. Figure 2 (b)
Shows the state after etching the silicon dioxide film 31.

Further, using the silicon dioxide film 31 as a mask, the silicon substrate 30 is anisotropically etched using a KOH aqueous solution to form alignment hole portions 34 and 35 of the micro optical element which penetrate the silicon substrate 30. This state is shown in FIG. All the slopes of the holes 34 and 35 have a plane orientation of (111), and the position, size and shape of the bottom can be controlled very accurately.

Finally, the silicon dioxide films 31 and 32 are removed by etching to obtain the silicon substrate 20b of FIG. The silicon substrate 20b manufactured as described above is bonded to the glass substrate 20a containing sodium by the well-known anodic bonding method to obtain the desired micro-optical element alignment member 20.

FIG. 2 is a schematic view showing an example of an optical system aligned using the micro-optical element alignment member of the present invention shown in FIG. Here, the optical system of the Michelson interferometer is shown as an example. The micro optical element alignment member 1 shown here corresponds to the micro optical element alignment member 20 shown in FIG. Of the optical elements that compose the Michelson interferometer, the polarization beam splitters 3, 4 and 6 and the total reflection prism 5 are included.
The fixed mirror 7, the quarter-wave plates 8 and 9, and the photodetector 10 are inserted into the alignment hole portions 21 to 27 of the micro optical element alignment member 1 and fixed by adhesion.
The laser 2 as the light source of the Michelson interferometer and the movable mirror 11 are not installed in the member 1.

As described above, in this embodiment, the alignment of the optical system using a large number of micro optical elements as shown in FIG. 2 is performed only by inserting each micro optical element into the alignment hole and adhering it. be able to.

[0015]

According to the present invention, the alignment of the optical system using the minute optical element can be performed very easily.
It eliminates the need for skilled workers and expensive mechanical alignment mechanisms. Therefore, it is possible to significantly reduce the cost in the alignment work.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a schematic plan view showing an interferometer aligned using the micro-optical element alignment member according to the present invention.

FIG. 3 is a schematic view showing a method for manufacturing a silicon substrate used in the present invention.

[Explanation of symbols for main parts]

 20 Micro Optical Element Alignment Member 20a Glass Substrate 20b Silicon Substrate 21 Alignment Hole 22 Alignment Hole 23 Alignment Hole 31 Silicon Dioxide Film 32 Silicon Dioxide Film 33 Photoresist

Claims (4)

[Claims] 1. A flat glass substrate and a flat silicon substrate bonded to the glass substrate, wherein the silicon substrate has a plurality of holes penetrating the silicon substrate formed by anisotropic etching. A micro optical element alignment member characterized by the above. 2. The micro optical element alignment member according to claim 1, wherein the silicon substrate has a plane orientation of (100). 3. The micro-optical element alignment member according to claim 1, wherein the glass substrate is glass containing sodium, and the glass substrate and the silicon substrate are bonded together by an anodic bonding method. Micro optical element alignment member to be. 4. A flat glass substrate and a flat silicon substrate bonded to the glass substrate, wherein the silicon substrate has a plurality of holes penetrating the silicon substrate formed by anisotropic etching. A micro-optical element alignment method comprising inserting a micro-optical element into the plurality of holes and adhering it to a micro-optical element alignment member.