JPH02131202A - Manufacture of optical waveguide - Google Patents

Abstract

PURPOSE:To easily manufacture a ridge type optical waveguide by bringing a stamper which has a pattern recessed corresponding to the optical waveguide into contact with the surface of a substrate, and charging an organic high polymer material in the pattern, curing the material with external energy, then separating the stamper from the surface. CONSTITUTION:The stamper 2 is pressed against the substrate surface 3a and ultraviolet-ray setting resin 4 is charged in the reflection optical waveguide pattern 26. In such a state, the substrate 3 is irradiated with ultraviolet rays UV from the other surface 3b to polymerize and cure the ultraviolet-ray resin 4. The stamper 2 is separated from the substrate 3, then the projecting optical waveguide 5 is formed on the substrate surface 3a. Further, the sectional shape of the pattern 26 is altered to obtain an optional sectional shape of the optical waveguide 5. Consequently, the ridge type optical waveguide 5 is easily manufactured by using the organic high polymer material and the height of the optical waveguide 5 can be varied.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a method of manufacturing a ridge-shaped guiding waveguide using an organic polymeric material.

(Example) Conventional technology Optical waveguides using organic polymer materials are cheaper and easier to manufacture than those using inorganic materials. A method shown in FIG. 5 is known for manufacturing an optical waveguide using this organic material. First, a cladding layer 14 (for example, 2 μm thick) made of polymethyl methacrylate (PMMA) is formed on a substrate 13 made of silicon (St) or the like [Fig. 5(a)
)reference〕.

On this cladding layer 14 is a core layer 15 (made of PMMA containing a dopant monomer to increase the refractive index).
For example, a thickness of 3 μm) is formed [see Figure 5 (bl)]
.

This core I! A photomask 17 having a pattern corresponding to the core is superimposed on the photomask 15, and ultraviolet rays are irradiated [see FIG. 5(C)]. In the portion of the core layer 15 irradiated with ultraviolet rays, the dopant monomer is polymerized, and a core 16 having a different refractive index from the surrounding area is formed. Finally, unreacted dopant monomers in the core layer 15 are removed by baking or extraction with a solvent [see FIG. 5(d)].

(c) Problems to be Solved by the Invention In the leading waveguide obtained by the above conventional manufacturing method, the core 16
The difference in refractive index between the core layer 15 and the surrounding core layer 15 is small, and the core 16
In places where the angle of light incidence on the core wall 16a is large, such as when the core wall 16a is bent, the condition for total internal reflection cannot be satisfied (the light confinement force is small), and there is a problem that the loss increases. Ta. Further, there was a problem in that it was difficult to vary the height (depth) h of the core 16, making it difficult to perform mode conversion.

The optical waveguide obtained by the conventional manufacturing method described above is a so-called buried type optical waveguide in which the core 16 is formed within the core layer 15, but an optical waveguide in which the core protrudes from the substrate surface is known as a ridge type optical waveguide. It is being In this ridge-shaped optical waveguide, since the core can be brought into contact with air or any other substance, a large difference in refractive index between the core and the surroundings can be achieved. However, the conventional manufacturing method described above cannot be applied to this ridge-shaped optical waveguide, and there is a problem in that it is relatively difficult to manufacture.

This invention was made in view of the above, and it is possible to easily manufacture a ridge-shaped optical waveguide by taking advantage of the characteristics of organic polymer materials, and also to manufacture an optical waveguide in which the height of the optical waveguide can be easily varied. The purpose is to provide a method.

(2) Means and operation for solving the problems In order to solve the above problems, the method for manufacturing an optical waveguide of the present invention includes closely contacting a stand bar having a recessed pattern corresponding to the optical waveguide to the surface of the substrate. The inside is filled with an organic polymer material, and after this organic polymer material is cured by external energy (e.g., plasma, heat, light, etc.), the stamper is separated from the surface, and an optical waveguide is formed on the surface of the substrate. It forms a protrusion. Therefore, a ridge-shaped optical waveguide made of organic polymer material can be easily manufactured.

Further, by changing the cross-sectional shape of the pattern, it is possible to obtain an arbitrary cross-sectional shape of the optical waveguide, and it becomes easy to perform mode conversion by changing the height of the optical waveguide.

(E) Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

First, a method for manufacturing the stamper 2 applied to this embodiment will be explained with reference to FIG. First, silicon (Si
), etc., a resist layer 22 is formed on a substrate 21 [second
See figure (a)]. Next, the resist R22 is irradiated with an electron beam 23, and a pattern 24 identical to the optical waveguide pattern is formed.
[See Figure 2(b)]. At this time, the height of the pattern 24 can be adjusted by controlling the amount of electron irradiation.

Next, the resist layer 22 is developed, leaving a pattern 24 on the surface of the substrate 21 (see FIG. 2(C)).Ni plating 25 is applied to this substrate 21 (see FIG. 2(C)).
d) see]. Finally, the substrate 21 is removed to obtain the stand bar 2 (see FIG. 2(e)).

In this standber 2, a concave inverted optical waveguide pattern 26 is formed by a pattern 24. In addition, Sukumba 2
For manufacturing, an ion beam lithography method or an exposure method using a photomask can be applied.

To manufacture an optical waveguide, first prepare the substrate 3 [first
See figure (a)]. This substrate 3 is made of a transparent material having a lower refractive index than the core 5 described later, such as polycarbonate (PC).
, polymethyl methacrylate (PMMA), glass plates, etc. can be used.

The substrate surface 3a is coated with an ultraviolet curing resin 4 [
See Figure 1(b)]. As this coating method, spin coating, dip coating, casting method, or roll extrusion method can be applied.

The stamper 2 is pressed so as to be in close contact with the substrate surface 3a [see FIG. 1(C)]. At this time, the ultraviolet curing resin 4
The inverted optical waveguide pattern 26 is filled. In this state, ultraviolet rays are irradiated from the other surface 3b of the substrate 3,
The ultraviolet curing resin 4 is polymerized and cured.

Finally, the stamper 2 is separated from the substrate 3 [Fig.
)reference]. A protruding optical waveguide section 5 is formed on the substrate surface 3a. Since this optical waveguide section 5 is in contact with air, it is possible to have a large difference in refractive index between the inside of the optical waveguide section 5 and the surrounding area. Therefore, even when the angle of incidence on the boundary surface becomes large, such as when the optical waveguide section 5 has a large bend, the amount of light emitted from the optical waveguide section 5 is small.

Note that it is also possible to first bring the stamper 2 into close contact with the substrate 3 and then fill the inverted optical waveguide pattern 26 with the ultraviolet curing resin by capillary action.

FIG. 3 shows an example in which the height h (and width W) of the waveguide portion 5° changes from h1 to hz (from W+ to wz) midway, making mode conversion possible. In this case, when creating the stamper 2, the height of the inverted leading waveguide pattern is varied by controlling the amount of electron irradiation as described above.

FIGS. 4(a) and 4(b) each show a modification of the cross-sectional shape of the optical waveguide portion 5. FIG. FIG. 4(a) shows an optical waveguide section 5A having a semicircular cross-sectional shape. In this optical waveguide section 5A, there is no corner, so transmission II! It has the advantage of reducing losses. FIG. 4(b) shows an optical waveguide 5B having a trapezoidal cross-section. This optical waveguide section 5B is
This has the advantage that it is easier to separate the stamper 2 from the substrate 3.

FIGS. 4(C) and 4(d) each show other modified examples. FIG. 4(C) shows an example in which a cladding layer 6 is further formed on the substrate 3. In this case, the optical waveguide section 5
The manufacturing accuracy can be made more relaxed than when no cladding layer is provided. Also, Figure 4? d) shows an example in which the substrate is an opaque silicon plate 3. A cladding layer 7 made of SiO2 or the like is formed on the silicon plate 3' in order to achieve low TTT loss. This cladding layer 7
An optical waveguide section 5 is formed thereon. In this case, since the ultraviolet rays cannot be irradiated onto the ultraviolet curable resin through 3 degrees of the silicon plate, the ultraviolet rays are irradiated from the direction along the leading waveguide pattern.

In the above embodiments, an ultraviolet curable resin is used as the resin that is polymerized and cured by external energy, but a resin that is polymerized and cured by heat or plasma may also be used.

(f) Effects of the Invention As explained above, in the method for manufacturing an optical waveguide of the present invention, a standber in which a pattern corresponding to the optical waveguide is recessed is brought into close contact with the substrate surface, and in this pattern, an organic polymer is After filling the organic polymer material and hardening the organic polymer material with external energy, the stamper is separated from the substrate surface and the optical waveguide is formed protruding from the substrate surface. It has the advantage of being easily manufactured using molecular materials. Furthermore, since the height of the optical waveguide can be changed, it has the advantage that an optical waveguide capable of mode conversion can be easily obtained.

[Brief explanation of the drawing]

Figure 1(a), Figure 1(a), Figure 1(C) and Figure 1(
d) is a diagram explaining the optical waveguide manufacturing process according to an embodiment of the present invention, FIG. 2(a), FIG. 2(b), and FIG. 2(C).
), FIG. 2(d) and FIG. 2(e) are diagrams explaining the manufacturing process of the stamper applied to the same example, and FIG. 3 is a diagram explaining the manufacturing process of the stamper applied to the same example. The perspective views illustrating the example, FIG. 4(a), FIG. 4(b), FIG. 4(C), and FIG. 4(d) are still other examples of the guiding waveguide manufactured in the same example. Figure 5 (a) is a diagram explaining each of the
, FIG. 5 et al.), FIG. 5(C), and FIG. 5(d) are diagrams explaining the manufacturing process of a conventional leading waveguide. 2: Stamper, 3: Substrate, 4: Ultraviolet curing resin, 5: Guide waveguide, 26: Inverted optical waveguide pattern. Figure 1 (a) Figure 1 (b) Figure 1 (d) Figure 1 (C) 2nd day 26. Anti-lunf-guide, tgii. Pattern figure (a) figure (a) figure (C) figure figure (b) figure (d) figure (a) figure (C) figure (b)

Claims (1)

[Claims] (1) A stamper having a recessed pattern corresponding to the optical waveguide is brought into close contact with the substrate surface, the pattern is filled with an organic polymer material, and this organic polymer material is cured by external energy, and then A method for manufacturing an optical waveguide, comprising separating the stamper from the surface of the substrate and forming an optical waveguide protruding from the surface of the substrate.