JPH0585887B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an optical branch circuit used in optical communication devices and the like.

Prior Art and Problems Conventional optical branching circuits include an optical fiber processing type in which the cores of optical fibers 1 and 2 are fixed close together until they interfere with each other, as shown in Figure 1a, and an optical fiber processing type as shown in Figure 1b. As shown, there is a type in which optical fibers 7 are branched into optical fibers 8 and 9 using lenses 3, 4, and 5 and a half mirror 6. However, although the former optical fiber processing type can be made compact, the processing of the optical fiber requires minute processing and is difficult to manufacture. In addition, those using the latter lens have the disadvantage that there are many positions for adjusting the positions of lenses and optical fibers, and that it takes time to manufacture and is large in size. Furthermore, there is also the drawback that once both are produced, the branching ratio is fixed.

OBJECTS OF THE INVENTION In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide a dynamic branching optical circuit which is small in size and whose branching ratio can be freely changed.

According to the present invention, the object is to provide a main line in which a first optical fiber is fused and fixed to a groove with a V-shaped or square cross section provided on the surface of a semiconductor or glass substrate, and a main line that is perpendicular to the main line. a light guide in which a transparent organic material whose refractive index changes in response to heat is embedded in a groove with a V-shaped or square cross section, a heating resistor film provided on the light guide, and a heating resistor film provided on the light guide; The groove provided at the end of the guide and having a V-shaped or square cross-section has an engaging portion in which a second optical fiber is melted and fixed, and propagation within the main line is caused by heating from the heating resistor film. This is achieved by providing a dynamic branching optical circuit characterized in that it directs a portion of the light into the second optical fiber.

Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a diagram for explaining the dynamic branching optical circuit according to the present invention. In the figure, 10 is a substrate;
Reference numeral 11 indicates a main line, 12 a branch line, and 13 a resistor thin film.

As shown in FIG. 2, this embodiment includes a main line 11 formed by melting and embedding an optical fiber in the surface of a substrate 10 made of a semiconductor such as silicon (Si) or gallium arsenide (GaAa) or glass; A branch line 12 formed by embedding a transparent resin whose refractive index changes in response to heat (for example, EPOTEK manufactured by EPOXY-TECHNOLOGYINC), and a line formed on the branch line, for example, Ni-Cr, etc. A resistor thin film 13 using a resistor thin film 13 is constructed.
Note that 14 and 15 are external optical fibers connected to the main line, 16 are optical fibers connected to the branch line, and 17 and 18 are terminals connected to both sides of the resistor thin film.

This embodiment configured as described above is created as follows.

First, as shown in the perspective view of FIG. 3a and the plan view of FIG. C ₆ H ₄ (OH) ₂ ): Ethylenediamine (N ₂ H ₄ C ₂ H ₄ ): Water = 25 g: 141.7 ml:
Etching is performed using an etching solution having a composition of 66.7 ml to create a V-groove. At this time, the portion 11' that becomes the main line only needs to have a width (for example, 150 μm) that allows the strand (for example, 125 μm) to be placed thereon, and the portion 12' that becomes the branch line exists at the branch ratio, but has a width of, for example, 50 μm.
Then, a widened V-groove with a width of 150 μm, for example, on which the fiber wire is placed is further prepared in the portion facing the periphery. The process of manufacturing the V-groove described above can employ a conventional semiconductor process, so it can be manufactured with great precision, and a large number of substrates with V-grooves can be obtained at one time.

Next, a main line (light guide) is fabricated on this substrate. Various methods can be considered for this, such as the sputtering method and the CVD method, but the simplest method is as shown in FIG. 21
along the inside of the V-groove 22, and the CO ₂ laser 2 is attached to this part.
3 is irradiated to melt and weld to the substrate 10.

Next, after fixing the optical fiber to the portion on which the fiber will be placed, which will become the branch path, an organic substance is poured into the V-groove between the optical fiber and the main line. This organic substance must have a property that its refractive index is smaller than that of quartz at room temperature and becomes larger than that of quartz when heated, or conversely, it is larger than that of quartz at room temperature and becomes smaller than that of quartz when heated. It also needs to be transparent (high transmittance) at wavelengths of 0.8 to 1.6 μm. If an adhesive such as "EPOTEX" (mentioned above) is used for this organic material, there is an advantage that fixing the strands of the optical fiber 16 and creating the light guide 12 can be done at the same time.

Finally, nichrome is deposited on the branch line by a method such as sputtering to form a resistor thin film 13, thereby completing the process.

In this embodiment formed in this way, the refractive index of the branch line 12 is changed by adjusting the current flowing through the resistor thin film 13, and the amount of light branched from the main line 11 is changed, that is, the branching ratio is adjusted. can do. Furthermore, since this embodiment does not use lenses, mirrors, etc., it can be manufactured compactly.

Effects of the Invention As described above in detail, the dynamic branching optical circuit of the present invention has a main line formed by melting an optical fiber, a branch line formed using an organic material whose refractive index changes with heat, Furthermore, the simple structure of providing a thin resistor for heating the branch line makes it possible to reduce the size of the device, and has great effects in that it enables the desired branching operation.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a conventional optical branching circuit, FIG. 2 is a diagram for explaining a dynamic branching optical circuit according to the present invention, and FIGS. 3 and 4 are for explaining its manufacturing method. This is a diagram. In the drawing, 10 is a board, 11 is a main line, 1
Reference numeral 2 indicates a branch line, and reference numeral 13 indicates a resistor thin film.

Claims (1)

[Claims] 1. V provided on the surface of a semiconductor or glass substrate
A main line in which a first optical fiber is melted and fixed in a groove with a shaped or square cross section, and a groove with a V-shaped or square cross section provided perpendicular to the main line, the refractive index of which changes in response to heat. A second optical fiber is inserted into a groove having a V-shaped or square cross section provided at the end of the light guide, and a heating resistor film provided on the light guide. a dynamic optical fiber having an engaging portion that is melted and fixed, and that part of the light propagating within the main line is guided into the second optical fiber by heating from the heating resistor film. Branch optical circuit.