JPH03156408A - Optical collimeter and optical coupling parts - Google Patents

Abstract

PURPOSE:To obtain an optical collimeter which does not change the direction of light to be outputted at all even if a ferrule is loaded/unloaded by inserting a photoconductor obtained by inserting an optical fiber into a precision capillary consisting of ceramics and mirror-finish-grinding both the ends into a cylinder or a divided sleeve and optically connecting both the members. CONSTITUTION:The photoconductor 5 obtained by inserting the optical fiber 3 into the precision capillary consisting of ceramics together with adhesive, fixing the fiber 3 and mirror-finish-grinding both the ends is inserted into the cylinder 2 consisting of a divided sleeve from its one end. After grinding the edge of one end of a convergent rod lens 1, the adhesive is applied to the side and head of the lens 1 and the coated lens 1 is inserted into the sleeve 2 and joined with the photoconductor 5. Then an optical fiber 7 having an optical fiber jacket 8 is inserted into the ferrule 6 together with the adhesive, the tip of the optical fiber 7 is mirror-finish-grounded to produce an optical fiber terminal parts 9, and the parts 9 is inserted into the cylinder 2. Even if the optical fiber terminal parts is loaded/unloaded, the output direction of light is not changed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a main component for configuring an optical branch/coupler and an optical fiber sensor used when constructing an optical fiber communication network transmission network. The present invention relates to an optical collimator that sends light output from an optical fiber into space as a light beam or inputs parallel light into the optical 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 a ball lens, 42 is a lens holder, 43 is a coil spring, 44 is a spring holder, 45 is a collimator holder, 46 is a ferrule insertion opening, and 47 is a ferrule guide hole.

The spherical lens 41 is placed in a lens holder 42 inserted into a collimator holder 45, and fixed with a coil spring 43 and a spring holder 44 with a male screw.

The ferrule (not shown) into which the optical fiber has been inserted is inserted into the ferrule guide hole 47 from the ferrule insertion opening 46 of the ferrule holder 45. The central axis of the optical fiber (not shown) is aligned with the central axis of the spherical lens 41 by a precisely machined ferrule (not shown) and a ferrule guide hole 47. The light output from the optical fiber is converted into parallel light by the ball lens 41 and output (Japanese Patent Application Laid-Open No. 63-20160
(See Publication No. 6).

Problems to be Solved by the Invention In an optical collimator having such a conventional configuration, since the optical connector is detachable, a small gap (several microns) is always created between the ferrule and the ferrule holder. Therefore, there is a problem in that the direction of light output from the optical collimator changes slightly each time the ferrule is attached or detached due to this small gap.

The present invention solves these problems and provides an optical collimator that does not change the direction of the output light at all even when the ferrule is attached or detached.

Means for Solving the Problems In order to solve the above problems, the present invention comprises a rod lens inserted into a cylinder or a split sleeve, and an optical fiber inserted into a precision capillary made of ceramic, with both ends mirror-polished. is inserted into the cylinder or split sleeve for optical coupling.

Effect If the rod lens and light guide are bonded with adhesive as described above, the incident position of the light to the lens will remain constant even when the optical fiber end is inserted or removed from the cylinder, so the light beam output from the lens will be emitted. The direction never changes.

Embodiment FIG. 1 shows a sectional view of an optical collimator according to an embodiment of the present invention. In Figure 1, 1 is a focusing rod lens, 2 is a cylinder made of a split sleeve, 3 is an optical fiber, 4 is a precision capillary, 5 is a light guide, 6 is a ferrule, 7 is an optical fiber, and 8 is an optical fiber jacket. , 9
is an optical fiber terminal component.

This will be explained in detail below. An optical fiber 3 is inserted and fixed together with an adhesive (not shown) into a precision capillary 4 made of ceramic having an outer diameter of 2+ nm, and both ends are mirror-polished to produce a light guide 5. This light guide 5 has an inner diameter of 2 mm and a wall thickness of 0.3 mm.
It is inserted from one end of a cylinder 2 made of a split sleeve made of ceramic (such as zirconia). 0.25 pitch focusing rod lens 1 (outer diameter 2mm, length 6.46+n
After polishing the edge of one end of m) with a diamond cutter etc.
Adhesive (not shown) is applied to the side surface and the tip thereof, and it is inserted into the split sleeve 2 and joined to the light guide 5. As shown in the figure, the rod lens 1 has one edge cut so that it can be easily inserted into the cylinder 2.

Next, an optical fiber 7 having an optical fiber jacket 8 is inserted into the ferrule 6 together with an adhesive (not shown), and the tip is mirror-polished to produce an optical fiber terminal part 9. By inserting this optical fiber terminal part 9 into the cylinder 2, the optical fibers 7 and 3 are optically coupled, and a parallel beam of light is output from the rod lens 1.

Since the light guide 5 is bonded to the rod lens 1 with an adhesive (not shown), the position of incidence of light on the rod lens 1 does not change. In addition, since the optical fiber end part 9 is optically coupled to the light guide 5 in the cylinder 2 with its optical axis adjusted, even if the optical fiber end part 9 is inserted into or removed from the cylinder 2, the light output from the rod lens 1 remains unchanged. The direction never changes.

FIG. 2 is a configuration diagram showing a voltage optical sensor which is one of the optical coupling components using the optical collimator of the present invention on the input side. In Fig. 2, la and lb are rod lenses, 2a and 2
b is a cylinder made of a split sleeve, etc.; 5 is a light guide; 9a;
9b is an optical fiber terminal component, 10a and 10b are fixed rings, 11° and 15 are polarizing beam splitters, 12 is an electro-optic crystal made of lithium niobate, 13a and 13b are electrodes, 14 is a 174 wavelength plate, and 16 to 21 are the above-mentioned This is the light that passes through the optical coupling component.

First, the operating principle of the voltage optical sensor will be explained with reference to FIG. In FIG. 3, 22 to 26 are the lights passing through the optical coupling components, and 27 to 31 are the lights passing through the polarizing beam splitter 11. Electro-optic crystal 12.1/4 wavelength plate 1
4. This is the polarization state after passing through the polarization beam splitter 15.

The light 22 without a polarization direction passes through the polarization beam splitter 11
When the light 23 is incident on the light beam, only the light 23 whose polarization state 28 is linearly polarized light is transmitted. When light 23 passes through the electro-optic crystal 12 with a voltage V applied to the electrode 13, the transmitted light becomes light 24 whose polarization state is elliptical due to the anisotropy of the electro-optic crystal 12.
outputs. When the 1/4 wavelength plate 14 is provided in the same direction as the crystal axis of the electro-optic crystal 12, it has the effect of converting the linearly polarized state to the circularly polarized state, so that the light 24 passes through the 1/4 wavelength plate 14.
When transmitted, light 25 of elliptically polarized light 30, which is close to circularly polarized light, is output.

When the light 25 passes through the polarization beam splitter 15, a linearly polarized light 26 is output. In the configuration of the voltage optical sensor described above, the amount of light 26 changes in proportion to the voltage V applied to the electrode 13 of the electro-optic crystal 12, and therefore,
The voltage V can be detected by the magnitude of the light 26.

Next, a voltage optical sensor using the optical collimator of the present invention will be described with reference to FIG.

Light 1 input from the optical fiber of the optical fiber terminal part 9a
6 is a parallel light beam 1 from the rod lens 1a after being optically coupled with the optical fiber of the light guide 5 by adjusting the axis with the split sleeve 2a.
7 outputs. The rod lens 1a is firmly fixed to the polarizing beam splitter 11 by using a fixing ring 10a to increase the bonding area.

The light 17 is reflected by the polarizing beam splitter 11 and becomes light 18, which is incident on the electro-optic crystal 12 to which a voltage V is applied to the electrode 13. The light 19 that has passed through the electro-optic crystal 12 and the 174-wave plate 14 is reflected by the polarizing beam splitter 15 to become light 20, which is focused by the rod lens 1b and enters the optical fiber of the optical fiber terminal part 9b, and the light 21 is Output.

In a voltage sensor using the electro-optic effect of the electro-optic crystal 12, light incident on the electro-optic crystal 12
When the incident light coincides with the crystal axis of the sensor, the temperature characteristics of the sensor hardly change. However, if the incident angle of light changes slightly, a problem arises in that the temperature characteristics of the voltage sensor change.

By using an optical collimator that uses a light guide 5 only at the input end, the incident angle of light to the electro-optic crystal 12 does not change even if the optical fiber terminal part 9a is attached or detached, so the temperature characteristics do not change. do not.

Effects of the Invention As described above, according to the present invention, the rod lens and the optical fiber terminal part are aligned in a cylinder by inserting the optical fiber into a precision capillary made of ceramic and passing through the optical guide whose both ends are polished. By optically coupling the optical fibers to each other, it is possible to obtain the effect that the output direction of light does not change even if the optical fiber terminal component is attached to and detached from the split sleeve. Furthermore, by using such an optical collimator whose output direction of light does not change on the input side of the voltage sensor, it is possible to suppress the influence of temperature characteristics on measured values.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an optical collimator according to an embodiment of the present invention;
Figure 2 is a cross-sectional view of a voltage optical sensor that is one of the optical coupling parts using the optical collimator of the present invention, Figure 3 is a diagram explaining the operating principle of the voltage optical sensor, and Figure 4 is a diagram of a conventional optical FIG. 3 is a cross-sectional view of a collimator. 1 , 1 a, l b --- Rod lens,
2.2a.

Claims (4)

[Claims] (1) One rod lens, one optical fiber inserted into a precision capillary having the same diameter as the above rod lens, and one optical guide having both ends mirror-polished, and having the same diameter as the above rod lens. It consists of one optical fiber terminal part with an optical fiber inserted into a ferrule and a mirror-polished tip, and one cylinder, and the rod lens and the optical fiber terminal part inserted from both ends of the cylinder form the cylinder. A light collimator optically coupled via the light guide within. (2) The optical collimator according to claim 1, wherein the cylinder is a split sleeve. (3) The optical collimator according to claim 1, wherein the cylinder and the precision capillary are made of ceramic. (4) An optical coupling component using the optical collimator according to claim 1 on the input side.