JPH03501895A - organic optical waveguide - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] ``Academic guidance'' The present invention relates to organic optical waveguides and also includes methods of manufacturing waveguide structures.

One structure for a nonlinear optical waveguide was published in the United Kingdom on October 28, 1987. It is described in patent application no. 2189624. This specifically states: It is. A linear polymer filament is deposited from a solution in an organic solvent onto a suitable support. Non-linear doping is applied to a part of the zero-order film surface that forms the film layer. The refractive index value is locally increased compared to the adjacent part of the film. produce a part. This makes it suitable for use in many optical logic and signal processing applications. We provide a nonlinear channel waveguide structure that can achieve this.

Doping additives used for this purpose must exhibit a high degree of nonlinearity in their molecules. Ru. However, the main effect of this property is the nonlinearity of the dopant material impregnated in is greatly reduced by the presence of the polymeric substrate, which tends to dilute the Therefore, the waveguide The majority of the channel volume is now occupied by the linear type of material, and this material cannot contribute in any way to the optical control of the transmitted signal.

The present invention was conceived to provide an alternative method of manufacturing optical waveguides. is a method that can take advantage of a substantial portion of the main effects of nonlinear materials. . Furthermore, the selection of possible materials as doping additives can be somewhat widened. Ru.

According to the present invention, a base film of a polymeric material is provided, in which a portion of the surface of the film is Dosing effective to locally increase the refractive index of the coalescing material and define the waveguide channel. a base film containing a polymeric additive, and wherein the polymeric material is a nonlinear optical material. A free optical device is provided.

One type of suitable nonlinear polymeric material is xyl-soluble polydiacetylene. . A special example is 10.12-docosadiin-1,22-diolbis(S-(-) -methylbenzylurethane), which will be referred to hereafter as 9SMBU.

The production and properties of various polydiacetylenes and related substrate films were reviewed in 1987. As described in patent application No. GB 8714511 filed on June 20, It is.

Some examples of suitable doping additives include 2-methyl-4-nitroaniline. Contains nitroaniline.

According to another aspect, the invention provides a support object with a nonlinear polymeric material on the surface thereof. The material is deposited to form a substrate film, and the deposition is carried out using a solution containing the material in an organic solvent. A mask material is deposited on the film surface, and a doping additive is added to the film surface. Remove the masked areas in the areas that need to be impregnated and place them in the doping additive solution. The masked substrate object is dipped into the exposed surface film portion of the additive. A method of manufacturing an optical device includes steps for promoting diffusion into a liquid. Attachment stage can be carried out either by a dip coating operation in which the support object is removed from the surface of the solution or by spin coating. It is carried out by a coating method to form a film with good optical quality. Ru.

At the end of the appropriate processing time, the support object with the base film is coated with the Bee 1 additive. Remove from solution. Next, if necessary, remove any residual mask material from the film surface. However, the manufacturing of the device may be completed.

By way of example, certain embodiments of the invention are described below with reference to the accompanying drawings. Figures 1 to 3 show different structures of waveguides, and FIG. 4 is a graph showing the absorption rates of polymer film materials.

The production of the optical waveguide of the invention provides a support object, which in this embodiment is a glass plate. Getting Started Next the board is coated with a base film of the number 9 SMBU compound. The required amount of this material is described in the aforementioned patent application no. 8714511. It was prepared in advance according to the method described above.

To attach the base film on the board, remove the board from a solution containing 93 MBU in chloroform. This is done by removing the solids present, in which case the solids concentration present is approximately 10% by weight. The plate removal speed was adjusted to 280zx/min. unsightly deposits is in the form of a film with a thickness of 0.4 μl, which has a red/orange color. It was showing. This effect is due to the extent to which the dip coating method results in alignment of polymer molecules on the plate surface. It was shown that the orientation was given as follows.

The process of introducing the necessary doping additives into the produced film is called “solvent assisted diffusion”. (Solvent-Assisted 1ndiffu-sion)” (S A ID) method, which uses a dopant and a saturated solution of the dopant. contacting the polymeric substrate in a two-phase system comprising: solvent is doping agent The molecules are brought into contact with the surface of the substrate at a constant speed while at the same time giving a uniform distribution on the substrate. Due to the presence of a solid dopant suspended in the solution, which acts as a transport medium for , ensuring a saturated solution and steady state at all times. The dope that has reached the surface of the substrate The surfactant molecules are subsequently solvated or penetrate into the substrate to form a solid solution. The molecules entering the surface will further diffuse into the matrix. The concentration of the dopant should be sufficient to cause a change in the refractive index. Yes, the depth of diffusion is determined by the thickness of the film. This results in a good A thickness that will give an effective waveguide with linearity but retains many modes This would avoid the formation of ugly waveguides.

In fact, the extent to which the refractive index throughout the thickness of the doped layer becomes locally increased A surface layer doped with an organic or organometallic compound up to the base polymer matrix formed during the process. polymer matrix by absorption from solution in an inert solvent The method of introducing the intermediate hedobe agent is controlled so that the degree of change in the refractive index can be changed. can be controlled. The main factors determining these characteristics of the resulting waveguide are: (a) properties of the dopant and solvent; (b) concentration of the solution; (e) processing timing; and (d) weight. The type of coalescing matrix and the phase of the dopant to the solvent and polymeric matrix. (e) treatment temperature, (f) nature of pretreatment, and (g>) in a saturated solution of Soak. Pour enough solution into the container to cover the substrate, and add as much solution as needed while stirring. Heat to temperature.

A condenser is necessary if the temperature used tends to cause excessive solvent evaporation. It will be. Temperature is best controlled by a thermostatically controlled bath or by refluxing the solvent. Maintained well. Sufficient amount of dopant to give a saturated solution with a slight excess is added to allow the system to reach equilibrium. The substrate is immersed in the solution for the required time. The solution Suspended solid dopant particles usually do not affect the method as long as it is agitated. However, if the dopant is in molten form at the temperature used, then the substrate is doped. Care must be taken not to be directly wetted by the agent droplets, or damage may occur. 0 Normal swirl will cause the droplet to adhere to the side wall of the container, resulting in uniform dispersion It will probably happen. The substrate may then be introduced, allowing the particles to adhere to the substrate surface. When non-uniform diffusion occurs due to electrostatic discharge, static electricity is often the cause. before soaking This is done by pre-treating the substrate with an anti-static gun. Usually effective in solving problems. After soaking, the substrate is cooled, washed, and dried. Good too.

Oka Niedan ff1 The selected dopants primarily increase the refractive index by diffusion into the polymeric substrate. should be able to do so. Therefore, it diffuses into the nonlinear polymer substrate to form a stable solid solution. non-reactive materials may be used unless they absorb the transmitted beam. will be possible.

Dopants include known non-linear compounds such as 5eNA, oNA, CINA, DAN; or benzophenone, substituted anophosuccinic acids, such as Fulgide ), or scandium tris butafluorodimethyl acetate ``Summer Five'' The function of the solvent used in the method of the invention is essentially to act as a transport medium. Ru. It should be inert and should not seriously dissolve or swell the substrate. There isn't. The dopant must be dissolved in the solvent to allow migration, but The solubility product should be small. There are two reasons for this. The first is to remove the base from the dopant solvent. Transfer to the body depends on its relative solubility in the solvent and polymer. parent to solvent If the bonding force is low and the affinity for the polymer substrate is high, the dopant molecules will bind to the substrate at the interface. It becomes easier to enter the direction.

Second, high solubility in the solvent means that large amounts of dopant can be incorporated. On the other hand, low solubility means that only a small amount of dopant can create a saturated solution. It means that it will be maintained.

For both high temperature diffusion of dopants and low temperature operation (where vapor losses are minimal) However, a high boiling point solvent is preferable.

Perfluorinated organic solvents are advantageous solvents in the process of the invention. It has been found to be a mediator. Most organic compounds undergo these changes at elevated temperatures. A wide range of such solvents are available ( PP range). However, the technology is perfluorination It is not limited to using solvents such as high boiling alkenes, e.g. Other solvents such as decane and Dow Corning 200 Silicone oils such as the series may also be used.

The following examples illustrate the method of the invention.

Example Dip coated 9SMBU with PP9 (mainly perfluoromethyldecalin isomer mixture) The material consists of 2- Immersion in a saturated solution of methyl-4-nitroaniline (MNA) at a temperature of 120”C. Diffusion was performed by soaking.

Using the method described in the example above, a more complex waveguide ellipse can be constructed as follows. can be formed. Matrix is placed on the surface of the matrix material using standard photolithography techniques. Define the schedule in advance. The holes defined in this mask allow the surface of the matrix material to be Allowing solvent diffusion to occur in selected areas of the surface to provide a channel waveguide structure Can be done.

This method allows curved waveguides, branched waveguides, directional couplers and Form a variety of active and passive channel waveguide structures, including interferometers can do. Typical waveguide species bodies are illustrated in FIGS. 1, 2, and 3. Radio & Electronic Engineer.

Vol, 53. No, 9. pp, 313-320.5ept, (1983 ), as illustrated in the paper by Bennion et al. .

Section 4 (a) shows a flat waveguide, and Section 4 (b) shows a curved waveguide. Figure 4(c) shows a Y-junction extended line waveguide. 4th (a) Plus in tl The tick substrate (2) is formed by solvent diffusion of a dopant that increases the refractive index within the phase (1). It has a waveguide surface phase (1) formed by. The waveguide shown in FIG. 3) Formed with a J-shaped waveguide channel by limiting solvent diffusion. It is. Figure 3 shows the solvent diffusion dopant being applied in a defined pattern in the surface phase (1). A Y-channel waveguide structure formed by a similar limit is shown.

In the waveguide of FIG. 3, for example, light directed along channel 4 passes through two paths ( 5) and (6). The paper by Bennion et al. The principles and uses of organic optical waveguides are described.

FIG. 4 is a graph showing the absorption rate of dopant materials in polymeric films. horizontal axis gives the wavelength (n-) of the light transmitted by the film sample, and the vertical axis shows the absorption. are doing.

The sample involves a 9SMBtJ film supported on a glass substrate, and the dopant material is He was an M.N.A. The amount of dopant material uptake with increasing immersion time in the solution is U Inspected by V/V IS spectroscopy, the absorption peak of MNA is at 3840- Similar peaks for 9 SMBU are at 482 and 530 nm (double II). It was expected that there would be.

The curves in the graph are for 1, 2.4 and 8 minute immersion of the film in the dopant solution. The results for 0 hours are shown together with the soaking time results. 2 minutes is the maximum of dopant material It was observed that this is the optimal time to provide uptake.

The dotted curve is the maximum incorporation of dopant material into the film, but Results are shown after a 14 day aging period. This means that polymerization Figure 2 shows the stability of the dopant material in the body film layer.

Although the method of the invention has been illustrated with particular reference to the diffusion of nitroaniline, other organic Dopants can also be used.

One particular application of this type of channel waveguide structure is, for example, the English Between semiconductor components as described in national patent ff1lff No. 2155194 The purpose is to provide an optical interconnect.

For example, one or more layers of polymeric material may be deposited onto an initial substrate and the structure ( If necessary, apply the next layer of polymer after curing and subjecting it to a solvent diffusion treatment. This also allows the formation of polyphase waveguide structures. Spin coating or dip coating The method is suitable for depositing two or more superimposed polymer matrix layers. be.

Channel waveguide structures such as those shown above define a desired pattern on a polymeric film. can be manufactured using standard photolithography techniques. such a method is a metal mask evaporated onto a polymer film (e.g. Well-defined channels are created by removing the aluminum after solvent diffusion. A waveguide is left behind. onto polymeric film by photolithography or other standard methods. The deposited metal layer does not need to be removed by solvent diffusion, but the diffused dopant is It can be used as a means to apply a field to align polar dopant molecules.

This last-mentioned method is particularly useful for the large second- and third-order magnetic susceptibilities of many polymer molecules. and especially for manufacturing optical nonlinear waveguide structures using intensity-dependent refractive index. Useful. Waveguides fabricated using such organic molecules can exhibit a wide range of nonlinear They will be able to perform the following functions: polyphasic and distributive feedback Similar to the structures described above, in the form of flat structures and numerous channel waveguide structures. can be done.

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Claims (12)

[Claims] 1. locally increasing the refractive index of the polymeric material in a base film of polymeric material; having a surface portion of the film containing a doping additive effective to define the waveguide channel; 1. An optical device having a base film that is a nonlinear optical material, the polymer being a nonlinear optical material. 2. 2. The device of claim 1, wherein the polymeric material is a chiral soluble polydiacetylene. 3. The device according to claim 1 or 2, wherein the polymeric material is 9SMBU as defined in the text. Placement. 4. Organicization where doping additives can enter the film surface by diffusion method The device according to any one of claims 1 to 3, which is a compound. 5. Claims 1 to 4, wherein the dope additive is 2-methyl-4-nitroaniline. The device according to any one of the above. 6. Prepare a base object and attach a nonlinear polymer material to its surface to form a surface film. and the deposition is carried out from a solution of the material in an organic solvent; The mask material is deposited on the surface of the mask, and the mask material is deposited on the surface of the mask in the area that requires impregnation with the doping additive. The masked substrate object is immersed in a solution of doping additive. , an optical device comprising steps for promoting the diffusion of said additive into a surface film. Production method. 7. Claim 6: The dope additive comprises a 2-methyl-4-nitroaniline compound. The method described in. 8.2-Methyl-4-nitroaniline compound in perfluoromethyldecalin 8. The method according to claim 7, wherein the method is added as a solution. 9. Any of claims 6 to 8, wherein the diffusion operation is carried out at a temperature in the range of 80°C to 160°C. The method described in item 1. 10. 10. The method according to claim 9, wherein the temperature range is 115<0>C to 125<0>C. 11. A method of manufacturing an optical device substantially the same as described herein. 12. Substantially the same optical system as described in the text with reference to any one of the attached figures. Device.