JPH02281211A - Optical collimator and optical coupling parts - Google Patents

Abstract

PURPOSE:To give a connecting function to an optical collimator and to make optical coupling parts compact and easy-to-use by constituting the optical collimator of a fixing member having a hole where a lens and an optical fiber are inserted and fixed and a split sleeve where the fixing member and an optical connector are made to abut and connected. CONSTITUTION:The optical collimator is constituted of one lens 1, one optical fiber 2 which is arranged in line by making the central axis thereof coincide with the lens 1, the fixing member 3 having the hole where the lens 1 and the optical fiber 2 are inserted and fixed and the split sleeve 5 where the fixing member 3 and the optical connector are inserted, made to abut and connected. Thus, the number of parts is reduced and the optical connector connecting type optical collimator is made inexpensive. Besides, the optical coupling parts which is compact and easy-to-use is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to emitting light output from an optical fiber into space as a light beam, applying optical changes such as polarization selection and wavelength selection, and then transmitting it again to other light beams. The present invention relates to an optical collimator optically coupled to a fiber and an optical coupling component using the optical collimator.

2. Description of the Related Art Conventionally, an optical coupling component using this type of optical collimator has a configuration shown in FIG. In FIG. 4, 41 is an optical fiber, 42 is a core of the optical fiber, 43 is a cladding of the optical fiber, 44 is a lens, 45 is a lens end face, 46 is a spherical lens surface, and 47 is a lens cladding.

The lens 44 is formed by processing the end face of an optical fiber having a core diameter larger than that of a single mode optical fiber into a spherical surface to form a lens end face 46 . The lens end face 45 is perpendicular to the central axis of the lens 44. Since the cladding 43 of the single mode optical fiber 41 has the same outer diameter as the lens cladding 47, a precision sleeve 48 is used to align the optical axes of the lens 44 and the optical fiber 41.

The light propagated through the core 42 of the optical fiber 41 is converted into parallel light by the spherical surface 46 of the lens 44 and output. (Unexamined Japanese Patent Publication No. 6
3-38909) Problems to be Solved by the Invention In such a conventional configuration, the lens 44 and the optical fiber 4
1 is connected, so if such an optical collimator is used to configure the optical coupling component C, it will be possible to input light to the optical fiber 41, output light from the optical fiber 41, etc. in order to optically couple with the optical fiber 41. Components such as optical connectors must be used. For this reason, the optical collimator is small (
However, there was a problem that the optical coupling parts were thick (and also had a large number of parts, making them expensive).

The present invention solves these problems by providing an optical collimator with a connection function and providing an optical connector-connected optical collimator with a small number of parts and an optical coupling component using the optical connector-connected optical collimator. It is something.

Means for Solving the Problems: one lens, one optical fiber aligned with the central axis coinciding with the lens, a fixing member having a hole into which the lens and the optical fiber are inserted and fixed, and the fixing member. It consists of a split sleeve that butts and connects a member and an optical connector, and allows the optical fiber connector to be attached and detached.

Since the working light collimator has a connection function and the optical connector-connected optical collimator is configured with a small number of parts, the optical coupling part can be made compact and easy to use.

Embodiment FIG. 1 shows the structure of an optical collimator according to an embodiment of the present invention. In Figure 1, 1 is a rod lens, 2 is an optical fiber, 3 is a lens fixing member, 4 is a split sleeve stopper, 5 is a split sleeve, 6 is a hook part of the split sleeve, 7 is an air hole, and 8 is an adhesive It is.

After pouring a small amount of adhesive into the hole slightly larger than 2 mm in diameter of the lens fixing member 3 made of ceramic,
A focusing rod lens 1 of 0.25 mm and 0.25 pitch is inserted. Then, from the opposite side of the lens fixing member 3,
An optical fiber 2 having a core diameter of 80 μm and an outer diameter of 125 μm is inserted into the μm hole. Focusing rod lens 1 and optical fiber 2
When both are pushed in so that they come into contact, the air hole 7 opens so as to intersect the focusing rod lens 1 and the optical fiber 2, so excess adhesive 8 flows out from the air hole 7.

After the adhesive 8 is cured, the focusing rod lens 1 and the optical fiber 2 are fixed to the lens fixing member 3 in close contact with each other. Thereafter, the end face of the optical fiber 2 is mirror polished.

One end of the split sleeve 5 is provided with a hook part 6 that is bent inside the cylinder, while the lens fixing member 3 is provided with a split sleeve stopper 4 in which a part of the cylindrical wall surface is recessed in a ring shape. When the hook part 6 is hooked on the stopper 4, the split sleeve 5 will be attached to the lens fixing member 3 when inserting or removing the ferrule (not shown) of the optical connector.
I will never leave. Therefore, when an optical coupling component is constructed by bonding the focusing rod lens 1 to another optical component, an optical connector can be directly connected, thereby reducing the number of components for the optical coupling component.

Although the lens fixing member 3 is made of ceramic, the lens fixing member 3 may be made of metal.

FIG. 2 is a diagram showing the configuration of an optical coupling component according to a second embodiment of the present invention. In Fig. 2, 1 is a rod lens, 2
is an optical fiber, 3 is a lens fixing member, 4 is a split sleeve stopper, 5 is a split sleeve, 6 is a hook part of the split sleeve, 7 is an air hole, 8 is an adhesive, 9 is a polarizing beam splitter, 10 is a polarizing film, 11 is a quarter wavelength plate, 12 is an electro-optic crystal, 13 is an electrode, 14 is a polarizing beam splitter,
15 is a polarizing film, 16 is an optical fiber, 17 is a jacket,
18 is a ferrule, 19 is an optical connector, and 20 to 27 are lights.

Before explaining the operation of the optical voltage sensor, which is an optical coupling component, the functions of the quarter-wave plate and electro-optic crystal, which are its main components, will be explained.

FIG. 3(a) is a diagram explaining the function of the 1/4 wavelength plate. In FIG. 3(a), 31 is linearly polarized input light, 32 is 1
/4 wave plate 1.33 is the direction of the crystal axis of the l/4 wave plate, 3
4 indicates circularly polarized output light.

The direction 33 of the crystal axis of the 174-wavelength plate 32 made of quartz and having a thickness of 29 μm is inclined at 45 degrees with respect to the linearly polarized incident light 31 . When linearly polarized incident light 31 enters the 174-wave plate 32, each polarized component in the direction of the two crystal axes 33 of the 174-wave plate 32 has a phase difference of π/2, so the output light 3
4 is converted into circularly polarized light. Therefore, 174 wavelength plate 3
Linearly polarized light incident 3 at an angle of 45 degrees to the crystal axis 33 of 2
1, the output light 34 becomes circularly polarized.

FIG. 3(b) is a diagram explaining the function of the electro-optic crystal. In FIG. 3(b), 35 is the electro-optic crystal, 36 is the electrode, 37 is the incident light of circularly polarized light, and 38 is the output light of elliptically polarized light. , 39 is the crystal axis of the electro-optic crystal, and 40 is the axis of the refractive index ellipsoid when a voltage is applied to the electrodes of the electro-optic crystal.

An electrode 36 is provided so that a voltage is applied to the lithium niobate crystal 35 in the X-axis direction. When a voltage is applied, the axis of the refractive index ellipsoid, which was coincident with the optical axis 39 of the crystal 35, is rotated by 45 degrees around the Z axis to become a coordinate axis 40. Circularly polarized incident light 37 is incident on the lithium niobate crystal 35 in the Z-axis direction.

The light that has passed through the lithium niobate crystal 35 undergoes phase modulation and is output as elliptically polarized light 38.

Therefore, when a voltage is applied to the circularly polarized incident light 37 in the X-axis direction of the lithium niobate crystal 35 and the light is transmitted in the Z-axis direction, it is output as elliptically polarized light, and the output is proportional to the magnitude of the voltage applied to the electrode 36. The state of the ellipse of the light 38 changes.

A second embodiment of the present invention will be described below with reference to FIG.

One optical connector for connection has a core diameter of 80 μm and an outer diameter of 125 μm.
An optical fiber 16 with a jacket 17 of μm has an outer diameter of 2 m.
It is constructed by attaching a ceramic ferrule 18 of size m and mirror-polishing the tip.

An optical fiber 2 with a core diameter of 80 μm and an outer diameter of 125 μm and a focusing rod lens 1 are inserted into a ceramic lens fixing member 3 together with an adhesive, and excess adhesive 8 is discharged from the lens fixing member 3 through an air hole 7.

Thereafter, the adhesive 8 is cured, and the focusing rod lens 1 and the optical fiber 2 are brought into close contact with each other and fixed to the lens fixing member 3. The tip of the optical fiber 2 is polished to a mirror finish, and a split sleeve 5 is attached.
is placed over the lens fixing member 3, and the hook portion 6 of the split sleeve 5 is inserted into the recess of the split sleeve stopper 4 of the lens fixing member 3, thereby forming an optical collimator. When the optical connector 19 is inserted into the split sleeve 5, it is held and fixed so that the optical axes of the optical fibers 2 and 16 are aligned.

The light 20 incident on the optical fiber 16a is output from the optical fiber 2a and then passes through the focusing rod lens 1 of the optical collimator.
It is converted into parallel rays 21 at point a.

The parallel light beam 21 is a converging rod lens 1a of an optical collimator.
The polarizing film 10 of the polarizing beam splitter 9 attached to the polarizing film 10 converts the light into linearly polarized parallel light 22. Parallel rays of linearly polarized light 22
l/4 wavelength plate 11 glued to polarizing beam splitter 9
When transmitted, it is converted into parallel light rays 23 of circularly polarized light. 17
X of lithium niobate crystal 12 adhered to 4-wavelength plate 11
Electrodes 13 are provided so that an electric field is applied in the axial direction. When a voltage V (v) is applied to the electrode 13, the refractive index changes due to the electro-optic effect of the lithium niobate crystal 12, so that parallel rays of circularly polarized light 23 and parallel rays of elliptically polarized light 24 transmitted through the lithium niobate crystal 12 is converted to The elliptically polarized parallel light beam 24 is selectively reflected in a specific plane of polarization by the polarizing film 15 of the polarizing beam splitter 14 bonded to the lithium niobate crystal 12, and becomes a linearly polarized parallel light beam 25. Parallel light rays 25 of linearly polarized light are transmitted through polarizing beam splitter 1
The light 26 is focused by the focusing rod lens 1b bonded to the fiber 1b, and the focused light 26 is coupled to the fiber 1b. Optical fibers 16b of the optical connector connected and held by the split sleeve 5b
Since it is connected to the optical fiber 2b, the light 26 is focused by the focusing rod lens 1b and the light 26 is transmitted from the optical fiber 16b.
It is output as 7.

Therefore, the light intensity of the light 27 output from the optical fiber 16b changes in proportion to the voltage applied to the electrode 13 of the lithium niobate crystal 12, so that it operates as a voltage sensor.

Although the optical coupling component is an optical voltage sensor, the optical coupling component may have any function as long as it uses a connected optical collimator. In addition, the optical fiber 2 has a core diameter of 8
Although the core diameter and the outer diameter of the optical fiber 2 are set to 0 μm and 125 μm, it goes without saying that there are no particular limitations on the core diameter and outer diameter.

Although the polarizing film 10 of the polarizing beam splitter 9 and the polarizing film 15 of the polarizing beam splitter 14 selectively reflect only a specific plane of polarization, the polarizing film 1 of the polarizing beam splitter 9
It goes without saying that the polarizing film 15 of the 0 and polarizing beam splitter 14 may selectively transmit only a specific plane of polarization.

Effects of the Invention As described above, according to the present invention, at least one lens, one optical fiber aligned with the central axis coinciding with the lens, and a hole into which the lens and the optical fiber are inserted and fixed. By configuring an optical collimator from a fixing member having a holder having a fixed member and a split sleeve into which an optical connector is inserted and butt-connected, the number of parts can be reduced and the cost of the optical connector-connected optical collimator can be reduced.

Further, by using an optical connector-connected optical collimator as an optical coupling component, it is possible to construct a compact and easy-to-use optical coupling component. Furthermore, since the optical connector-connected optical collimator does not have a jacketed optical fiber, it has the advantage that the optical fiber does not break.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the optical collimator according to the first embodiment of the present invention, FIG. 2 is a diagram showing the configuration and operation of the optical voltage sensor according to the second embodiment of the present invention, and FIG. FIG. 4 is a diagram showing the change in the plane of polarization when a voltage is applied to a four-wave plate and a lithium niobate crystal, and FIG. 4 is a diagram showing the configuration of a conventional optical collimator. 1... Focusing rod lens, 2... Optical fiber, 3... Lens fixing member, 4...
... Split sleeve stop, 5... Split sleeve,
6...Catch part of split sleeve, 7...
...Air hole, 8...Adhesive, 9...
Polarizing beam splitter, 10...Polarizing film, 11
....l/4 wave plate, 12 .... lithium niobate crystal, 13 .... electrode, 14 ....
・Polarizing beam splitter, 15...Polarizing film, 1
6... Optical fiber, 17... Jacket, 18... Ferrule, 19...
Optical connector, 20-27... light. Name of agent: Patent attorney Shigetaka Awano and one other person\CXJc
r)+Lq litori ward

Claims (3)

[Claims] (1) A lens, a single optical fiber aligned with the central axis of the lens, a fixing member having a hole for inserting and fixing the lens and the optical fiber, and an optical fiber in the fixing member. An optical collimator comprising a split sleeve into which a connector is inserted and butt-connected. (2) a first polarizing beam splitter that reflects the parallel light beam output from the first optical collimator and converts it into linearly polarized light; and a quarter wavelength that converts the linearly polarized light beam into circularly polarized light. a plate, a lithium niobate crystal that converts the circularly polarized light beam into elliptically polarized light by an applied voltage, and a second polarizing beam splitter that converts and reflects the elliptically polarized light beam into linearly polarized light. An optical coupling component comprising: a second optical collimator that couples the optical beam converted into linearly polarized light by the second polarizing beam splitter to an optical fiber. (3) The optical coupling component according to claim 2, wherein the light output from the optical collimator passes through the first and second polarizing beam splitters.