JPS60196707A - Optical device - Google Patents

Abstract

PURPOSE:To make adjustment of an optical axis unnecessary by providing a hole, to which a functional element is set, in the center part of a plate-shaped block and forming a V-shaped groove with this hole as the center desiredly on the surface of this block. CONSTITUTION:A circular hole 17 is provided vertically in the center part of an angular plate-shaped block 11 consisting of a metal, and V-shaped grooves 12A and 12B, whose axes coincide with each other, on both sides of the circular hole 17 and a V-shaped groove 12C whose axis is orthogonal to those of V-shaped grooves 12A and 12B are formed with the circular hole 17 as the center on the surface of this block 11. A collimating lens (optical passive element) 15A is inserted to the V-shaped groove 12A, and its end face is brought into contact with the side wall of a stopper material 18A. Collimating lenses 15B and 15C are inserted to V-shaped grooves 12B and 12C, and their end faces are brought into contact with side walls of the stopper material 18. Consequently, these optical passive elements are set vary easily, and adjustment of optical axes is unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an optical device such as a demultiplexer, a multiplexer, an optical switch, etc., in which functional elements are installed between optical fibers.

(b) Background of the technology Optical devices such as optical multiplexers, optical multiplexers, and optical switches attach collimating lenses to each of the terminal parts of an input optical fiber and an output optical fiber to optically couple them. Generally, a functional element such as a coupler film or a prism is installed between collimating lenses.

(c) Conventional technology and problems FIG. 1 is a cross-sectional view of a conventional sufficient wave device.

In FIG. 1, a recess 1A is provided in the center of a housing 1 made of metal, such as stainless steel. The housing 1 has insertion holes 2A and 2B whose axes coincide with each other on both sides of the recess IA, and an insertion hole 2A.

An insertion hole 2C is bored perpendicular to the axis of the shaft 2B.

4A is a cylindrical holder made of metal, such as stainless steel, which is inserted into the insertion hole 2A and bonded with the adhesive 3. An input optical fiber 5A is inserted into the axial hole of the holder 4A. A collimating lens 6A (for example, a ball lens) is inserted into the large-diameter axial hole at the tip of the axial hole at a position separated by the focal length from the end surface of the input optical fiber 5A.

4B and 4G are output-side holders inserted into the insertion holes 2B and 2C, respectively, and bonded with the adhesive 3, and have the same shape as the holder 4A. Output light beams 5B and 5C are inserted into the axial holes of the holders 4B and 4C, respectively. Collimator lenses 6B and 6C (for example, spherical lenses) are inserted into the large-diameter axial hole at the tip of the axial hole, respectively, at positions separated by a focal length from the end surface of the output optical fiber 5B5C.

Reference numeral 7 denotes a filter film formed by depositing a dielectric multilayer film on the surface of the glass substrate 7A, which transmits light with a wavelength λ1 and reflects light with a wavelength λ2. The filter film 7 is fixed in the recess IA so as to be inclined at 45 degrees with respect to the optical axis of the input optical fiber 5A.

The optical demultiplexer configured as described above has an input optical fiber 5.
When a combined wave of wavelengths λ1 and λ2 is emitted from A, it is separated by a filter 117, and the light of wavelength λ1 is transmitted to the optical fiber 5B, and the light of wavelength λ2 is transmitted to the optical fiber 5C.

However, the optical axis of the holder and the axis on the outer shape cannot be perfectly aligned due to the precision of the parts, and are slightly deviated from each other. In order to efficiently connect the holder 4A, holder 4B, and holder 40, it is necessary to align the optical axis of the transmitted light emitted from the holder 4A fixed to the two insertion holes of the housing l and split by the filter film 7 with the optical axis of the holder 4B. Adjust the misalignment or inclination of the axes of the holder 4B and the holder 40 so that the axes and the optical axis of the reflected light and the axis of the holder 40 match to achieve the highest coupling efficiency. Glue 3
must be held until it hardens.

Such adjustment work not only requires delicate techniques but also requires a large number of man-hours.

(d) Object of the Invention In view of the above-mentioned conventional problems, the object of the present invention is to provide an optical device that does not require adjustment of the optical axis by inserting each optical member having a circular or spherical outer shape into a groove. Our goal is to provide the following.

(e) Structure of the Invention In order to achieve this object, the present invention provides a hole in the center of a plate-like block into which a functional element is installed, and a desired groove on the surface of the block around the hole. After forming a collimating lens and inserting a stopper material into the hole, insert a collimating lens into each of the grooves so that the end surface contacts the stopper material, and then insert a collimating lens in a position opposite to each collimating lens. Insert a spacer and a ferrule with the same diameter, and press each collimating lens and ferrule into the corresponding V groove using an elastic presser plate that is fixed to the surface of the block, and then remove the stopper material. Then, the functional element is mounted in the hole to construct an optical device.

(f) Embodiments of the Invention The present invention will be described in detail below with reference to illustrated embodiments.

Figure 2 is a diagram showing the assembly process of an embodiment of the present invention (A).
3 is a sectional view, (b) is a sectional view along the dotted line M-M shown in (a), (c) is a plan view, and FIG. 3 is a plan view after assembly.

In FIG. 2, reference numeral 11 is a rectangular plate-shaped block made of metal, for example, stainless steel. A circular hole 17 is vertically provided in the center of the block ll.

On the surface of the block 11, on both sides of the circular hole 17, there are V#1112A and 12B whose axes coincide with each other, and a V groove 12.
A, 12 B (D-axis center intersecting V groove 12 C) are formed on the surface of the block 11. Also, a set screw 20 is provided on the surface of the block 11 for tightly fixing a presser plate 19 to the surface.
Screw holes 21 into which the two screws are screwed are arranged in parallel.

A soft cylindrical stopper material 1B made of Teflon, for example, is fitted into the circular hole 17 and has an appropriate elasticity that does not damage the surface of the lens. 15A.

15B and 15C are collimating lenses (for example, spherical lenses) having the same outer diameter, and collimating lens 1
5A is inserted into the V-groove 12A, and its end surface is in contact with the side wall of the stopper material 18.

The other collimating lenses 15B and 15C are inserted into the V-grooves 12B and 12G, respectively, and their end surfaces abut against the side walls of the stopper material 18, respectively.

13A is a cylindrical ferrule made of metal such as stainless steel, and its outer diameter is equal to the outer diameter of the collimating lens 15A. An input optical fiber 14A is inserted into the axial hole of the ferrule 13A. Also 13B,
Reference numeral 13C is a cylindrical ferrule made of metal, such as stainless steel, and has the same shape as the ferrule 13A, and its outer diameter is formed to be equal to the outer diameter of the collimating lens 15A. An output optical fiber 14B and an output optical fiber 14C are inserted into the axial holes of the ferrules 13B and 13C, respectively. Ferrule 13A is in V groove 12A, 7e7
The L'-rule 13B is in the V groove 12B, and the ferrule 13C is in the V groove.
Collimator lenses 15A, 15B, and 15G are inserted into the groove 12C, facing each other.

16A, 16B, and 16C are hollow cylindrical metal spacers of the same shape and size, and their outer diameters are equal to or slightly smaller than the outer diameter of the ferrule 13A. teeth,
It is sandwiched between the collimating lens 15A and the ferrule 13A, between the collimating lens 15B and the ferrule 13B, and between the collimating lens 15G and the ferrule 13C, and is placed in the V-groove so as to come into contact with the end surface of the ferrule and the end surface of the collimating lens. It has been inserted.

In this way, the ferrule 13A and collimating lens 15A
The length of the spacer 16A is determined so that when the spacer 16A is inserted between the two, the end face of the input optical fiber 14A is located at the focal length of the collimating lens 15A. Furthermore, the lengths of the other spacers 16B and 16C are similarly determined.

Reference numeral 19 denotes a holding plate made of an elastic thin metal plate, for example, a stainless steel plate. The external dimensions of the presser plates 1 and 9 in plan view are approximately equal to the external dimensions of the block 11, and a hole slightly larger than the circular hole 17 is provided in the center.

The holding plate 19 has the respective V grooves 12A and 12 as described above.
Collimator lenses 15A and 15 inserted in B and 12C
B, 15C, ferrule 13A.

Block 1 so as to press the apex surfaces of 13B and 13C
1, and is fixed closely to the surface of 1 by means of a set screw 2o. Note that, unlike the illustrated example, if the apex surfaces of the ferrule and collimating lens are located at a lower position than the surface of the block 11, the apex surfaces of the ferrule and collimating lens may be pressed together through a spacer plate of an appropriate thickness. Just do it.

After crimping the ferrule and collimating lens to each groove in this way, attach the stopper material 18 as shown in Figure 3.
is removed by extrusion through the circular hole 17, and the filter film 7 is attached to the circular hole 17 so as to be inclined at 45 degrees with respect to the optical axis of the input optical fiber 14A.

In the optical demultiplexer configured as described above, the end face of each optical fiber is fixed to the focal length position of the corresponding collimating lens by each spacer, and the optical axis and the axis of each ferrule are Since they match, there is no need for adjustment. Therefore, when the combined waves of wavelengths λ1 and λ2 are outputted from the input optical fiber 5A, they are demultiplexed by the filter film 7 and the light of wavelength λl is efficiently transmitted to the optical fiber 5B. , the light of wavelength λ2 is transmitted to the optical fiber 5C.

Note that although the illustrated example uses a ball lens as the collimating lens, it is needless to say that the present invention is not limited to a ball lens and may be implemented with, for example, a drum lens or a Selfox lens. In particular, if a Selfox lens with a length of 0.25 of the wavelength is used, the focal length can be easily changed without the need for a spacer.

Furthermore, the present invention is not limited to the illustrated example; for example, the blocks may be hexagonal instead of square, and the grooves may be made obliquely intersecting each other as appropriate rather than being orthogonal. Alternatively, the functional element is not a filter film but an element with other functions, so that it is not a sufficient wave filter.
The present invention can be appropriately modified and implemented in other optical devices such as optical switches and optical multiplexers.

(g) Detailed Description of the Invention As described above, in the present invention, each optical passive element having a circular or spherical outer shape is inserted into the groove, and the mounting of the optical passive element is extremely easy. In addition, it is an optical device that has excellent practical effects, such as not requiring adjustment of the optical axis.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional optical demultiplexer, and FIG. 2 is a diagram showing the assembly process of an embodiment of the present invention, in which (a) is a sectional view and (b) is a dotted line M-- shown in (a). A sectional view of part M, (c) is a plan view, and FIG. 3 is a plan view after assembly. In the figure, 5A, 14A are input optical fibers, 5B, 5C, 14
B, 14C are output optical fibers, 6A, 6B, 6C, 15
A, 15B, 15C are collimating lenses, 7 is a filter film, 7A is a glass substrate, 11 is a block, 12A, 12
B, 12C are V grooves, 13A, 13B, 13c are ferrules, 16A. 16B and 16C are spacers, 17 is a circular hole, 1B is a stopper material, and 19 is a presser plate. Ko 1 Figure [In9

Claims (1)

[Claims] A hole into which a functional element is mounted is provided in the center of a plate-like block, and a desired shape is formed on the surface of the block around the hole.
A ferrule and a collimating lens having the same outer diameter are inserted into each V-groove and are pressed and fixed by an elastic holding plate closely fixed to the surface of the block. An optical device characterized by: