JPS6116045B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical coupling/branching circuit.

As a ball lens optical system, multiple convex lenses and
A combination lens made by gluing concave lenses together,
Alternatively, a rod lens, etc., in which the refractive index is maximum at the center and decreases in a parabolic manner toward the periphery, is conventionally used. Axis alignment takes a lot of time and effort, and each lens requires polishing to achieve surface precision, making it expensive.Also, with rod lenses, not only is it difficult to control the manufacturing precision of the refractive index distribution, but it is also difficult to It is necessary to pass the light beam through it and cut it into a highly accurate length, which also requires a lot of time and effort, and has the disadvantage of increasing production costs.Moreover, when combining such a ball lens optical system with an optical fiber, However, there were problems such as difficulty in aligning the centers of the two with high precision.

The present invention aims to solve these problems and provide an optical coupling/branching circuit that can be mass-produced and that can combine an optical fiber and a ball lens optical system with high precision. be.

Embodiments of the invention will be described below with reference to the drawings.

In FIG. 1, 1 is a sphere made of an optical material such as TiO ₂ or Al ₂ O ₃ , and 2 and 3 are cylindrical envelopes made of an optical material such as glass or acrylic that surround the sphere 1. The sphere 1 is inserted into a two-split mold (not shown) that forms a cylindrical groove with approximately the same diameter as the cylindrical groove 1, and glass, acrylic, etc. are press-fitted from both sides of the cylindrical groove to form a cylindrical outer surrounding part 2, 3, and then finish the outer parts 2 and 3 with high precision using a centerless grinder so that they have the same diameter as the sphere 1. From the sphere 1 which forms a convex lens and the cylindrical outer parts 2 and 3 which form a concave lens, A spherical lens 4 can be obtained.

Therefore, the center of the end face of the outer enclosure 2 is accurately determined using laser beam means, and a hole 5 is made from this point along the center line of the outer enclosure 2 to reach the surface of the sphere 1 (FIG. 2). In this case, since the outer envelope 2 and the sphere 1 are made of different materials, it is possible to accurately open the hole 5 until it reaches the surface of the sphere 1.

Next, an optical fiber 6 with an optical matching material 7 such as balsam attached to the tip having substantially the same refractive index as the optical fiber is inserted into the hole 5, and the tip of the optical fiber 6 is attached to the sphere 1 as shown in FIG. Glue and fix to the surface.

In this way, an optical fiber assembly in which the optical fibers 6 are accurately combined with the ball lens 4 can be obtained.

FIG. 4 shows the case of constructing a connector, in which each sphere consisting of the sphere 1, the cylindrical outer enclosures 2 and 3, the sphere 1', and the cylindrical outer enclosures 2' and 3' is shown in FIG. A connector for transmitting light from the optical fiber 6 to the optical fiber 6' can be obtained by bonding the end faces of each assembly, which is a combination of lenses and optical fibers 6 and 6', in mutually symmetrical positions.

FIG. 5 shows an embodiment of the present invention in the case of configuring an optical coupling/branching circuit. Each end face of the assembly consisting of the outer envelopes 16, 17 and the optical fiber 18 is made a 45 degree inclined surface, and these end faces are glued together via a mirror _M1 , and a sphere 19, a circle is formed in a direction perpendicular to the assembly. An assembly consisting of columnar outer enclosures 20, 21 and an optical fiber 22, and an aggregate consisting of a sphere 23, cylindrical enclosures 24, 25, and an optical fiber 26 are provided, respectively, and the cylindrical outer enclosure Mirror on the end of 25
It is constructed by bonding the mirrors M ₂ , and the mirrors M ₁ ,
For example, if the characteristics of M ₂ are as shown in FIG. 6, the mirror M ₁ does not transmit light of wavelength λ ₁ , _and
If it is assumed that the mirror M ₂ does not transmit the light of _{the wavelength λ 3 but} transmits the light of the wavelengths λ ₁ and λ ₂ , the optical fibers 18 and 26 transmit the light of the wavelengths λ ₁ and λ, respectively. When the light of ₂ is incident, the light of wavelength (λ ₁ +λ ₂ ) is transmitted to the optical fiber 22,
From the optical fibers 26 and 18, respectively, the wavelength λ
₁ and λ ₃ , the optical fiber 14
When light of wavelength (λ ₁ +λ ₃ ) is transmitted to optical fiber 22, and conversely, light of wavelength (λ ₁ +λ ₂ ) is incident on optical fiber 22, light of wavelength λ ₁ and λ ₂ is transmitted to optical fibers 18 and 26, respectively. When the light of wavelength (λ ₁ +λ ₃ ) is transmitted and input into the optical fiber 14,
Optical fibers 18 and 26 each have a wavelength λ ₃
and λ ₁ light is transmitted, and the light can be coupled and branched.

In FIG. 7, the optical branching/demultiplexing circuit shown in FIG. 6 is made compact by molding 27 with the same material as each cylindrical envelope.

As explained above, according to the present invention, manufacturing is easy and mass production is possible, and optical fibers and spherical lenses can be combined with high precision.

[Brief explanation of the drawing]

Fig. 1 is a front view of the ball lens, Fig. 2 is a front view of the apertured lens, Fig. 3 is the assembly of the ball lens and optical fiber, and Fig. 4 is the front view when forming a connector. Figure 5 is a front view of an embodiment of the present invention when configuring an optical coupling/branching circuit, Figure 6 is a characteristic diagram of a mirror, and Figure 7 shows a molded state of what is shown in Figure 5. It is a front view. In the figure, 1, 1' are spheres, 2, 3, 2', 3' are cylindrical enclosures, 4 is a spherical lens, 5 is a hole, 6, 6' are optical fibers, 11, 15, 19, 23 is a sphere, 1
2, 13, 16, 17, 20, 21, 24, 25
is a cylindrical envelope, 14, 18, 22, and 26 are optical fibers, and M ₁ and M ₂ are mirrors.

Claims (1)

[Claims] 1. In an optical coupling/branching circuit, a ball lens is formed by surrounding a sphere with a cylindrical envelope having the same diameter as the sphere, and a hole is formed along the center line of the envelope on the end face of the envelope. Then, using an optical fiber assembly in which an optical fiber is inserted and fixed into the hole, when joining the optical fiber assembly to each other, the joining surface of the outer envelope is a 45° inclined surface,
An optical coupling/branching circuit characterized in that a half mirror is provided on the joining surface, and another optical fiber assembly is provided in a direction perpendicular to the joined optical fiber assembly. 2. In the optical coupling/branching circuit, a hole is formed along the center line of the outer envelope in the end face of the outer envelope of a spherical lens formed by enclosing a sphere with a cylindrical outer envelope having the same diameter as the sphere, and a hole is formed along the center line of the outer envelope, and light is passed through the hole. When using an optical fiber assembly in which fibers are inserted and fixed, and when joining the optical fiber assembly to each other, the joining surface of the outer envelope is an inclined surface of 45 degrees,
A half mirror is provided on the joint surface, and another optical fiber assembly is provided in a direction perpendicular to the joined optical fiber assembly to serve as an optical coupling/branching section.
An optical coupling/branching circuit characterized in that a branching part is molded with the same material as the surrounding part.