JPS61261707A - Optical parts for optical communication - Google Patents

Abstract

PURPOSE:To moderate positional and angular accuracy with good balance and to attain non-adjustment of an optical axis by uniting one lens group obtained by dividing respective lenses into two lens groups with a light emitting/ photodetecting element or an optical fiber to form a collimeter. CONSTITUTION:Optical beams consisting of components lambda2, lambda3 are reflected by an interference film filter 10-1, the optical beam lambda2 is coupled with a projection fiber 15-3 through an interference film filter 10-2 and the optical beam lambda3 is coupled with a projection fible 15-4. The 1st lens 3-1 and the 4th lenses 7-1-7-3 are fixed in a support 14 and the collars of the support 14 and a terminal 13 are abutted each other and fixed each other by adjusting the optical axis to form the collimeter. Consequently, non-adjustment of the optical axis can be attained with the working accuracy of mechanical parts to be sufficiently mass-produced and the cost of the optical parts can be sharply reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to optical components for optical communications, and particularly to a lens collimator I-system that constitutes a part of the optical system.

Conventionally, the light beam emitted from a light emitting element or optical fiber is not simply coupled to another optical fiber or light receiving element;
In order to add functions such as add/drop, multiplex/demultiplex, optical path switching, attenuation, etc., lenses are often used as a means of propagating and combining light beams in optical components for optical communications. .

In the conventional lens system, one lens is placed in each of the input ports and one lens is placed in each of the output ports.

There are three conventional methods for adjusting the optical axis of optical components. The first method is to fix the light emitting/light receiving element or the optical fiber and finely adjust the position of the lens. The second method is to fix the lens and finely adjust the position of the light emitting/light receiving element or optical fiber. In both the first and second methods, the required fine-tuning accuracy of the position is extremely strict. peek
and a lens integrated as a collimator.
□ It is a method of adjusting. In this method, contrary to the first and second methods, the positional accuracy of the collimator may be loose, but the required angular accuracy is very strict. Therefore, with conventional optical components, it is difficult to reduce the price because it requires a large amount of man-hours to adjust the optical axis, or extremely high-precision mechanical parts are required to eliminate the need for optical axis adjustment. there were.

Purpose of the Invention The object of the present invention is to provide an optical component for optical communication that can eliminate the need for adjusting the optical axis with sufficient machining precision for mechanical components that can be mass-produced, and can significantly reduce the cost. .

Structure of the Invention The optical component for optical communication according to the present invention includes a light introduction element, two input side lenses arranged close to the light introduction element on the introduction optical axis of the light introduction element, and a light guide: shoulder. 1+′!
″・′″′)11″(D )s *J-1c = (7
) Two output-side lenses arranged close to the light emitting element and inserted between the input-side lens and the output-side lens to process and guide the introduced light based on a predetermined processing function. an optical element, the light introduction element and the lens closer to the light introduction element of the two input lenses are fixed together, and the light introduction element and the two output lenses are fixed together. It is characterized in that the lens closer to the light guide element is fixed integrally with the lens.

Example Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention. The light beams emitted from the light emitting elements or optical fibers 4-1 to 4-n are transmitted to the lenses 3-1 to 3-n and the second lenses 2-1 to 2-2-n, respectively.
After passing through n, the beam becomes a parallel beam and enters the functional element 1 for adding/dropping, multiplexing/demultiplexing, optical path switching, attenuation, etc.

After the parallel beams are subjected to the necessary processing for propagation through the functional element 1, they are emitted from the functional element 1, and are each passed through a third lens 6-1.
~5-m and fourth lenses 7-1 to 71::I,
It is focused by a photodetector or an optical fiber.
1 Ao” Combined with 8-1 to 8-m.

4′ -1e□i51c yo ii 7.4-1~4-. Wow.

1 (1~5-n 4myo') -(Ai (E 8
n, っIJ)! -9e ff5 Ji12 Luns 3
-1 to 3-n each have a light emitting side holder 5-1-1'1. On the other hand, the light receiving element or optical fiber 8
-1 to 8-m and the fourth lens 7-1 to 7-m are on the light receiving side t
:'II *JL19-1~9-mk-,,t:.

-h (L g h-1, knee v2.5) 1 It forms a limiter. In this way, conventionally each ``!!: 1, .

Pa:) Zo, Cgae, V/tsu□Air 1. B7.
Ia, o-1. .

] The difference from the conventional method is that

'1 According to the configuration of the present invention] The positional and angular accuracy required for the remeter is significantly higher than that required for the emitting/receiving element or optical fiber in the conventional configuration. Call! Schiff is relaxed.About its principle using drawings];
j Explain.

□゛l Figure 2 [DIJ,/! -, system,
7) Ede...Gasashi. . (.)Me indicates the model of the conventional collimating system, and ('B), ゛・÷ indicates the model of the collimator 1 to system in the configuration of the present invention.
show. Coupling loss and positional deviation ΔX or angular deviation △ from fiber output power 40 to fiber input power pout
The relationship with θ is shown in FIG. 3 for a conventional collimating system and in FIG. 4 for a collimating system according to the present invention. In addition, in FIGS. 3 and 4, the conditions are that both the light emitting side and the light receiving side use a core diameter of 50 μm and NA=0.2 GI fiber.

Comparing Figures 3 and 4, we can see that when the apparent core diameter is expanded as a remeter by the second lens 2 and the fourth lens 7, the sensitivity of the coupling loss increases with respect to an angular deviation of 80°. However, the sensitivity to positional deviation ΔX is significantly relaxed. The precision that can be easily mass-produced using current processing technology is approximately 100 μm in dimensional precision and 0.2 degree in angular precision.

As can be seen from FIG. 3, even if an attempt was made to eliminate the need for adjusting the optical axis, extremely high-precision mechanical parts were required, which was an obstacle to lowering the price.

On the other hand, as can be seen from FIG. 4, with the configuration of the present invention, it is possible to freely balance the required position accuracy and angle accuracy, and the optical axis can be adjusted using relatively low-cost mechanical parts. It is possible to eliminate the need for adjustment. Furthermore, even if all optical axes are not adjusted, the number of adjustment steps can be significantly reduced if the accuracy is relaxed.

Furthermore, Maej! IS's conventional RIF-1 one-way system is completely similar in that the position viscosity is significantly relaxed, and the angle precision II becomes too strict, making it difficult to balance position accuracy and angle accuracy. I can say that.

FIG. 5 shows the structure of a three-wavelength optical demultiplexer realized by applying an embodiment of the present invention. Terminal 13 of input fiber 15-1
The wavelength λ1. emitted from the tip of the The light beam of λ2° 3 becomes a parallel beam after passing through the first lens 3-1 and the second lens 2-1, propagates through the glass block 11, and reaches the interference film filter 10-1. Here, only the component of λ1 passes through the interference film filter 10-1, is focused by the third lens 6-1 and the fourth lens 7-1, and is coupled to the output fiber 15-2.

On the other hand, one of the light components of λ2 and λ3 is filtered through the interference film filter 1.
0-1, the light beams of λ2 each pass through an interference film filter 10-2 and then enter the output fiber 1.
5-3, and the light beam of λ3 is coupled to the output fiber 15-4. 3rd lens 3-1 and 4th lens 7-1 to 7-
3 is fixed inside the boat 14, and the boat 14 and the terminal 13 are fixed.
By butting the ribs together to adjust the optical axis and fixing them together, a remeter is formed.

The boulder 12 is made by cutting metal or the like with high precision. A collimator is installed in the U grooves 16-1 to 16-4 around the holder 120, and a glass block 11 is installed in the counterbore in the center of the bottom.
By supporting the optical axis by pressing it against the reference surface 17-1, 17-2, it is possible to fix the optical axis with high precision.

The specifications used in this example are as follows.

λ1 = 1300nm, λ2 = 780nm, λ3
=880nm Radius of curvature of hemispherical lens: L5mm Interference film filter: LWPF and SWP However, mass production is good. In this example, as a result of fixing the collimator and glass block without adjustment, the additional coupling loss was within 13 dB.

In addition, the assembly man-hours (well, conventional) can be reduced to 1/3 compared to a three-wavelength optical demultiplexer constructed using a remate system, confirming that the present invention is effective in reducing the cost of optical components.

Effects of the Invention As is clear from the above explanation, in the present invention, in a lens collimating system conventionally used as an optical system for optical components, each lens is divided into two parts, and one of the parts is used to emit light/
By integrating the light receiving element or the optical fiber to form a collimator, positional and angular accuracy can be harmoniously relaxed. As a result, it becomes possible to eliminate the need for adjusting the optical axis with sufficient machining accuracy for mechanical components that can be mass-produced, resulting in the effect of significantly reducing the cost of optical components.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of an embodiment of the present invention, Figure 2 (A) is a model diagram of a conventional lens/collimating system, and Figure 2 (B) is a model diagram of the lens/collimator 1 system of the present invention. The model diagrams, FIGS. 3 and 4 show each lens and lens according to the conventional and the present invention.
The characteristics of the collimating system are shown in FIG. 1, and FIG. 5(A) is a plan view of an application example of the present invention, and (+-3) is a cross-sectional view taken along the line AA'. Explanation of symbols of main parts 1... Functional optical element 2.3.6.7... Lens 4... Light emitting element or optical fiber 8...
Light receiving element or optical fiber 9.12...Holder

Claims (1)

[Claims] a light introduction element, two input-side lenses arranged close to the light introduction element on the introduction optical axis of the light introduction element, a light extraction element, and two input lenses arranged on the introduction optical axis of the light introduction element; Two output-side lenses arranged close to this light guiding element are inserted between the input-side lens and the output-side lens to process and guide the introduced light based on a predetermined processing function. an optical element, the light introduction element and the lens closer to the light introduction element of the two input lenses are fixed together, and the light introduction element and the two output lenses are fixed together. An optical component for optical communication, characterized in that a lens closer to the light guiding element is fixed integrally with the lens.