JP2001242429A - Fiber shape light element and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the optical element (device) with easy alignment, capable of the miniaturization and arraying, and to provide its production method. SOLUTION: A fiber shape light element is comprised of a fiber covering having heat resistance of 100 deg.C or more, and optical fibers has a transparent electrode provided at the end face and the side face. Then, a pair of the optical fibers provided with the transparent electrode in the end face and the side face to face with a interval of the end faces, is arranged so that both optical axes may be aligned. A material and element, having electro-optic effect and the optical modulation effect are filled with or inserted in gap between the end faces of the optical fibers, the intensity of the light and the polarized wave are controlled, or the wavelength is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-type optical device and a method for manufacturing the same, and more particularly, to a method for manufacturing a fiber-type optical device having transparent electrodes on the end face and side faces of the optical fiber.
The present invention relates to a fiber-type optical element that controls or controls light loss, polarization, and phase, or emits and receives light, by applying or injecting a current to a functional material, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, various optical devices using optical fibers, for example, devices for controlling light loss and polarization have been reported and are commercially available. Most of the light from the optical fiber is made into a collimated beam by a lens and fly into free space.
In many cases, the light is transmitted through an element having an electro-optic effect, a light modulation effect, and a filter effect, is further condensed by a lens, and is coupled to an output optical fiber.

As an example, a variable optical attenuator and a variable wavelength filter of a type in which an ND filter or a wavelength filter is inserted between two opposed collimators to move or rotate the place are developed. Alternatively, a variable optical attenuator that controls light loss by sandwiching a liquid crystal layer sandwiched between two glass plates with transparent electrodes by opposed collimating fibers,
Tunable wavelength filters have been developed, and polarization control elements for controlling polarization are also commercially available.

[0004]

However, since these elements use a collimator, there is a problem in that an effort is required for alignment of the optical fiber, the element becomes large, and it is difficult to form an array.

In order to couple light from a semiconductor laser or a light emitting diode to an optical fiber, or to couple light from an optical fiber to a detector, these elements are mounted on a mount and a lens is mounted. It was necessary to arrange and arrange the elements, which required labor.

In an element in which light passes through a transparent electrode,
Indium Tin Oxide (Indium Tin Oxide), which is a transparent electrode, is usually formed on a glass substrate.
O). The transparent electrode ITO has a high transmittance in the visible light, but the transmittance decreases as the wavelength becomes longer. In the near infrared wavelength band of 1.55 μm, which is a communication wavelength band, the influence of the plasma absorption edge by the carrier causes There is a problem that the transmittance is reduced to 50% even when the film thickness is 40 nm.

[0007] The same problem also occurs with transparent electrodes such as In ₂ O ₃ , SnO ₂ , and ZnO. In addition, when these transparent electrodes are formed on an optical fiber, it is difficult to form a transparent electrode having a high transmittance on the end face of the optical fiber because the heat resistance of the coating of the optical fiber is low.

It is an object of the present invention to provide an optical element (device) which can be easily aligned, miniaturized and arrayed, and a method of manufacturing the same.

Another object of the present invention is to provide an optical fiber type device in which a transparent electrode is formed on an end face and a side face of an optical fiber, and a light emitting element and a light receiving element are provided on the end face, and a method of manufacturing the same. .

Another object of the present invention is to provide an optical fiber type element using a transparent electrode having high transmittance in a visible light / near infrared wavelength band formed on an end face and a side face of an optical fiber, and a manufacturing method thereof. It is in.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0012]

The outline of the invention disclosed in the present application is briefly described as follows.

(1) In a fiber type optical element, a fiber coating has a heat resistance of 100 ° C. or more, and a transparent electrode is constituted by an optical fiber provided on an end face and a side face.

(2) In the fiber type optical element of the means (1), a pair of optical fibers each having the transparent electrode provided on an end face and a side face are opposed to each other with an interval between the end faces,
In addition, they are arranged so that their optical axes coincide with each other, and a material or element having an electro-optic effect and a light modulation effect is filled or inserted into a gap between the end faces of the optical fiber, and the intensity and polarization of the light are controlled. Or select a wavelength.

(3) In the fiber type optical element of the means (1), the one optical fiber is fixed to a substrate, a vertical groove is provided in the optical fiber, and a transparent electrode is provided on a wall surface of the groove. A material or element having an electro-optic effect or a light modulation effect is filled or inserted into the groove to control the intensity and polarization of the light or to select a wavelength.

(4) In the fiber type optical element according to the means (2) or (3), the material having the electro-optic effect and the light modulation effect is a nematic liquid crystal, a polymer dispersed liquid crystal,
Any one of a polymer network liquid crystal, a ferroelectric liquid crystal, a cholesteric-nematic phase transition liquid crystal, a dynamic scattering liquid crystal, or an electrochromic material, wherein the element having the electro-optic effect and the light modulation effect is a semiconductor planar light-emitting device. It is a modulator or an electro-optic crystal plane type light modulator.

(5) In the fiber type optical element of the above means (1), any one of an electroluminescence element, a surface emitting laser, and a surface type detector is provided on the transparent electrode on the end face of the optical fiber.

(6) In the fiber type optical element of the above means (5), the electroluminescence element may be an organic thin film electroluminescence, an inorganic thin film electroluminescence obtained by doping ZnS or ZnSe with a light emitting element, or a Zn thin film electroluminescence.
It is composed of an organic dispersion type electroluminescence in which an S phosphor is mixed with a binder, and an electroluminescence mainly composed of one of ultrafine Si films.

(7) In the fiber type optical device according to any one of the means (1) to (6), the transparent electrode is made of indium tin oxide (ITO), In ₂ O ₃ , SnO.
₂ and any one of ZnO.

(8) In any one of the means (1) to (7), the coating of the optical fiber is made of metal or polyimide.

(9) In the method of fabricating a fiber type optical element, any one of indium tin oxide (ITO), In ₂ O ₃ , SnO ₂ , and ZnO is sputtered or coated on the end face and side face of the optical fiber. A transparent electrode is formed by vapor deposition.

(10) In the method for manufacturing a fiber-type optical element according to the means (9), the pair of optical fibers having the transparent electrodes formed on the end face and side face are opposed to each other with an interval between the end faces, and Are arranged so that the optical axes of
In the gap between the end faces of the optical fiber, an electro-optic effect,
This is a method of filling or inserting a material / element having a light modulation effect.

(11) In the method of the above (10), wherein the optical fibers are opposed to each other,
The jig for arranging the optical axes so as to coincide with each other includes one of a V-groove, an optical fiber connection splice, an optical connector including a ferrule and a sleeve, and a microcavity.

(12) In the method for producing a fiber-type optical element according to the means (10), the method for forming a transparent electrode on the end face and side face of the optical fiber may be any one of a sputtering method, a vapor deposition method, and a coating method. And the temperature for forming the transparent electrode or the heat treatment temperature is 100 ° C. to 400 ° C.

(13) One optical fiber is fixed to the substrate, a groove is formed perpendicular to the optical fiber, a transparent electrode is formed on the wall surface of the groove, and the groove has an electro-optic effect and a light modulation effect. What is claimed is: 1. A method for producing a fiber-type optical element in which a material or an element is filled or inserted, wherein the material in which the optical fiber is fixed to a substrate is polyimide, and the polyimide is melted and cured at a temperature of 100 ° C. to 400 ° C. It is.

That is, the point of the present invention is to form a transparent electrode on the end face and side face of the optical fiber so that the alignment of the optical fiber is easy and the optical fiber can be arrayed. That is, a splice for optical fiber bonding, a V-groove array, a microcavity, an optical connector, and the like, which are used as devices, are used. Another problem is that the optical fiber is fixed in the groove, the groove is provided perpendicularly to the groove, and a transparent electrode is formed on the wall surface of the groove to eliminate the need for alignment.

Further, as a light source / light receiving element for an optical fiber, a structure and a manufacturing method in which a layer or an element which emits light by a voltage, an electric field, and an electric current or a layer or an element which receives light are formed and installed after forming the transparent electrode. And realized a method that is easy to miniaturize, array, and align.

The present invention can be applied to not only glass fibers but also plastic fibers as optical fibers.

Further, it has been found that the temperature for forming a transparent electrode having a high transmittance is from 100 ° C. to 400 ° C. In particular, in the case of ITO, it has been found that the transmittance increases when the temperature for forming the ITO and the heat treatment temperature are changed from 100 ° C. to 400 ° C. Furthermore, it has been found that when the substrate temperature is set to 100 ° C. and the heat treatment temperature is changed from 300 ° C. to 350 ° C., the transmittance in the visible to near-infrared wavelength band is improved to nearly 100%. The transmittance in the communication wavelength band of the 20 nm thick ITO manufactured by this method becomes 99% or more.

The transparent electrode is not limited to ITO, and it has been found that the substrate temperature and the heat treatment temperature are optimally from 100 ° C. to 400 ° C. for conventionally known transparent electrodes such as In ₂ O ₃ , SnO ₂ , and ZnO. Further, when a transparent electrode is formed on a normal optical fiber or an optical fiber inserted into a ferrule under the above conditions, the normal coating layer (protective film) is a UV coat having low heat resistance, and the adhesive between the ferrule and the optical fiber is used. Since the heat resistance is low, the UV coat and the adhesive are burnt and blackened. In the present invention, it has been found that a metal coat or a polyimide coat is optimal as a coating material instead of the conventional UV coated fiber having heat resistance of 100 ° C. or less.

The present invention is not limited to the above, and can be applied to all fiber-type optical elements having transparent electrodes formed on the end face and side face of the optical fiber.

Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) according to the present invention.

[0033]

(Embodiment 1) FIG. 1 is a perspective view showing a schematic configuration of an optical attenuator (fiber type optical element) according to Embodiment 1 of the present invention, and FIGS. It is a figure for explaining the manufacturing method of the shown optical attenuator (fiber type optical element). 1 to 3, 1-1 is an optical fiber core (for example, using a glass fiber), 1-2 is an optical fiber coated with a protective film, and 1-2A is a protective film (coated) made of metal or polyimide. Layer), 1-3 is an ITO transparent electrode formed on the end face and side face of the fiber, 1-4 is a glass splice holder, 1-5 is a micro glass gallery having a V groove 1-5A, 1-6 is a splice lid, Reference numeral 1-7 denotes a metal plate for holding down a fiber, and reference numeral 1-8 denotes a material having the above-mentioned electro-optic effect or light modulation effect (for example, a polymer network liquid crystal, a polymer dispersed liquid crystal, a cholesteric-nematic liquid crystal, or the like) is used. Reference numeral 9 denotes an extraction electrode, and reference numeral 1-10 denotes an insulating film.

As shown in FIGS. 1 to 3, an optical attenuator (fiber-type optical element) according to the first embodiment includes, for example, an optical fiber core 1-1 made of glass fiber and a protective film made of metal or polyimide. (Coating layer) Optical fiber 1-2 coated with 1-2A, ITO transparent electrode 1-3 formed on the end face and side face of optical fiber 1-2, glass splice holder 1-4, V groove 1-5A Micro glass gallery 1-5, lid 1-6 of glass splice holder 1-4,
Metal plate 1-7 for holding fiber, material having electro-optic effect or light modulation effect (for example, using polymer network liquid crystal, polymer dispersed liquid crystal, cholesteric-nematic liquid crystal, etc.) 1-8, extraction electrode 1-
9 and an insulating film 1-10.

As shown in FIG. 2, a method for manufacturing an optical attenuator (fiber-type optical element) according to the first embodiment is as follows.
As shown in (a), an optical fiber 1-2 in which a protective film (coating layer) 1-2A made of, for example, polyimide is coated around the optical fiber core 1-1 is prepared. Alternatively, an optical fiber in which a metal is coated on the optical fiber core 1-1 may be used. These optical fibers 1-2 have been developed as submarine optical fibers in order to improve reliability.
It is readily available.

When a bare optical fiber without the protective film (coating layer) 1-2A is used, the side surface of the optical fiber is scratched and cheap.
ITO transparent electrodes can be formed at temperatures up to 400 ° C,
It is difficult to fabricate a device that is easy to break and can withstand practical use, and the optical fiber requires a heat-resistant protective film (coating layer) 1-2 as in the present invention.

Next, as shown in FIG. 2 (b), a polyimide coat (protective film) 1-1 of the optical fiber 1-2 is formed with a fiber stripper so that the optical fiber core 1-1 comes out about several cm.
Peel off 2A. At this time, if the temperature of the stripper is set as high as 700 ° C., the polyimide coat (protective film) 1-2A
Is easily peeled off. Alternatively, the protective film (coating layer) 1-2 can be peeled off by immersion in sulfuric acid heated to about 100 ° C. Hydrochloric acid for metal-coated fiber,
The metal protective film (coating layer) 1-2A can be removed by immersion in an acid such as sulfuric acid.

As shown in FIG. 2B, the optical fiber 1-2 is cut by a fiber cutter so that the end face of the optical fiber 1-2 becomes flat. Desirably, the characteristics are further improved by polishing the end face of the optical fiber 1-2.

In this state, the substrate is put into an ITO vapor deposition device or a sputtering device. Next, as shown in FIG.
An ITO transparent electrode 1-3 is provided on the end face and side face of the optical fiber 1-2.
Is formed by sputtering or vapor deposited so that is formed. In the case of sputtering, an ITO transparent electrode 1-3 is formed on the entire end face and side face. On the other hand, in the case of vapor deposition, the ITO transparent electrode 1-3 is provided on the end face and part of the side face.
Is formed. Since the heat-resistant temperature of polyimide is 400 ° C and the temperature of metal is higher than that, in order to increase the transmittance, the substrate temperature is set to 100 ° C, ITO is formed by sputtering about 40 nm, and the temperature of the optical fiber 1-2 is changed to an oxygen atmosphere. Anneal at 350 ° C. for about two and a half hours.

FIG. 4 shows that the annealing increases the transmittance of the transparent electrode in the communication wavelength band. FIG. 4A shows a transmission spectrum before annealing, and FIG.
(B) 40 nm I annealed at 350 ° C. for 150 minutes
3 shows a transmission spectrum of TO. It can be seen that at a communication wavelength of 1.55 μm, a loss of 1.0 dB is improved to a loss of about 0.2 dB. (This spectrum also includes a reflection loss. Excluding the reflection loss, the maximum transmittance in the visible region is almost the same. 100% transmittance). A similar effect is obtained when the substrate temperature is from 100 ° C. to 300 ° C. and the annealing temperature is from 200 ° C. to 4 ° C.
Obtained at 00 ° C. The ratio of Sn to In is 0.
To 10 wt% is desirable.

Further, the transparent electrode 1-3 is not limited to ITO, and the substrate temperature and the heat treatment temperature are optimally 100 ° C. to 400 ° C. for conventionally known transparent electrodes such as In ₂ O ₃ , SnO ₂ , and ZnO. Was.

Next, as shown in FIG. 2D, an optical fiber splice holder 1-4 generally available as an optical fiber connector is prepared. Here, four cores are shown, but one, four, eight and twelve cores are commercially available. The optical fiber is inserted into the V-groove 1-5A and the micro cavities 1-5 from both sides. Usually, the matching oil is applied to the portion where the optical fiber faces, but an optical fiber splice holder (for example, a glass splice holder) 1-4 from which the matching oil has been removed is used.

As shown in FIG. 3A, the optical fiber 1-2 is inserted from the left and right sides of the micro cavities 1-5, and the length of the gap 1-8A is adjusted while observing with a microscope. The material 1-8 having the electro-optic effect or the light modulation effect is filled in the gap 1-8A of the optical fiber 1-2. As the material 1-8, for example, a polymer dispersed liquid crystal,
Polymer network type liquid crystal, cholesteric-nematic phase transition liquid crystal, dynamic scattering liquid crystal, or the like is used. At this time, if an alignment film is required, the optical fiber is immersed in the alignment film and dried in advance. Usually, in the case of the above-mentioned liquid crystal, an alignment film is not required.

In the case of a polymer dispersion type or polymer network type liquid crystal, it is solidified by irradiating ultraviolet rays UV.

Next, as shown in FIG. 3 (b), a lead-out electrode 1-9 for taking out the electrode is formed from the ITO transparent electrode 1-3 on the side surface of the optical fiber 1-2 by using an adhesive or a conductive paste. And take it out.

Further, as shown in FIG. 3C, in order to accurately position the optical fiber 1-2, the opening of the glass splice holder 1-4 is covered with a lid 1-6, and the optical fiber 1 is closed. -2 is pressed down with the metal crimp plate 1-7 and pressed down. At this time, when a metal plate is used as the pressing lid 1-6, the opposing optical fiber 1
A thin insulating film 1-10 is used as a spacer so that the ITO transparent electrode 1-3 does not short-circuit.

FIG. 5 shows the characteristics of the optical attenuator manufactured by the above process. The gap of the optical fiber is about 10 μm, and the filled liquid crystal is a polymer network liquid crystal. It operates at a very low voltage of about 1.5 V, consumes power of μW, can control the loss from about 10 dB to about 0.2 dB, and has no polarization dependence. Furthermore, it was very easy to form an array with up to 12 cores, and a compact, multi-core optical attenuator was realized.

In the manufacturing process, the optical fiber 1-2 was aligned using the glass splice holder (optical fiber splice holder) 1-4, but the optical fiber 1 was positioned on the V groove array of Si, glass, and plastic. -2 may be aligned, or the glass microferrule may be taken out of the glass splice holder 1-4 and aligned. The optical fiber 1-
2 may be inserted, and the optical fibers 1-2 may be inserted from the left and right sides of the sleeve for the optical connector for alignment.

Cholesteric-nematic phase transition liquid crystal,
When a polymer-dispersed liquid crystal or a dynamic scattering liquid crystal is used, the driving voltage is as high as about 10 V.
Similar optical attenuator characteristics were obtained.

In the above description, the groove is filled with the liquid crystal material.
The same effect was obtained with the electrochromic material. Further, a surface type modulator such as a III-V semiconductor surface type modulator such as InP or GaAs or an electro-optic crystal typified by LiNbO ₃ is inserted, and the transparent electrode formed on the end face of the optical fiber 1-2 is connected to the surface. Even when the modulator was sandwiched by the optical fibers 1-2 so that the electrodes on the back surface of the type modulator were in contact with each other, light could be similarly modulated and attenuated.

(Embodiment 2) In Embodiment 1, a method of manufacturing an optical attenuator for controlling light loss has been described. In Embodiment 2, an arbitrary polarization is converted into a polarization in a specific direction. The optical polarization control device will be described.

FIGS. 6 and 7 show the steps of manufacturing the optical polarization control element (fiber-type optical element) according to the second embodiment of the present invention. In FIGS. 6 and 7, 4-1 is a polyimide alignment film, 4-2 is a rubbing roll, 4-3 is a marker indicating a rubbing direction, and 4-4 is a nematic liquid crystal.

The steps up to the preparation of the optical fiber, the cutting of the end face and the deposition of ITO are the same as those in FIG. The transparent electrode is not limited to ITO, but may be any of the conventionally known In ₂ O ₃ , Sn
A transparent electrode such as O ₂ or ZnO may be used.

As shown in FIG. 6A, the optical fiber 1-
2 is immersed in a polyimide alignment film solution, dried and cured to form a polyimide alignment film 4-1. Next, as shown in FIG. 6B, rubbing is performed by adjusting the fine moving table so that the roll of the rubbing machine 4-2 contacts the tip of the optical fiber 1-2. At this time, the rubbing direction of the end face of the optical fiber 1-2 is marked on the side face of the optical fiber with the marker 4-3.

Next, as shown in FIG. 6C, the rubbed optical fiber was inserted into a fiber splice (glass splice holder 1-4) in an antiparallel or 90 ° orientation when facing each other. Fix in the same way as above. next,
As shown in the left diagram of FIG. 7A, the liquid crystal is a nematic liquid crystal, and a parallel alignment cell is formed when the optical fibers face each other in an anti-parallel manner, and a twisted nematic alignment is formed at 90 degrees.

When the voltage is turned on, the liquid crystal molecules are oriented parallel to the optical axis as shown in the right diagram of FIG. That is, in the case of a parallel alignment cell, it operates as a variable wavelength plate, and in the case of a twisted nematic liquid crystal, it operates as an optical rotation element that rotates the polarization by 90 degrees.

As shown in FIG. 7B, when the parallel orientation elements are inclined at 45 degrees to each other and two elements are connected, an arbitrary elliptical polarization can be converted into a linear polarization in a specific direction. Further, the polarization control element can change the phase of light, and can also be operated as a variable phase element.

The gap 1-8A between the optical fibers 1-2 is several μm to several tens μm, and the loss is almost 0 dB due to the high transmittance of ITO. In the present invention, a four-core example is shown in the figure, but one-, four-, eight-, and twelve-core polarization control elements can be realized using commercially available splices.

Further, although not shown in the drawing of the second embodiment, if a dielectric mirror is further formed on the ITO at the end face of the optical fiber 1-2, a Fabry-Perot etalon is formed, and the liquid crystal is formed. By applying a voltage, it is also possible to realize a variable wavelength filter.

Although the case where the liquid crystal is filled has been described above, the polarization can be controlled even if an optical crystal plate having an electro-optical effect is inserted and sandwiched between the optical fibers 1-2 with the transparent electrodes. Was.

In the second embodiment, the case of a nematic liquid crystal has been described. However, similar effects can be obtained by using another liquid crystal, for example, a ferroelectric liquid crystal.

(Embodiment 3) In Embodiment 3 according to the present invention,
In contrast to the first and second embodiments in which a pair of optical fibers are opposed to each other, a groove is dug vertically in one optical fiber.
An example in which O is formed on the end face and side face of the optical fiber is shown.

FIGS. 8 and 9 are diagrams showing the steps of fabricating the fiber optical device of the third embodiment. 5-1 is a protective film (coating layer) coated with polyimide or metal, and 5-2 is an optical fiber. 5-3 is an insulating substrate having a V-shaped groove 5-3A formed thereon, 5-4 is a polyimide for fixing an optical fiber,
5-5 is a groove formed by dicing, 5-6 is a blade of a dicing saw, 5-7 is an ITO transparent electrode formed on a wall surface and a side surface, 5-8 is a liquid crystal filled in the groove, 5-5. 9 is an extraction electrode.

As shown in FIG. 8A, the method for manufacturing the fiber optical device of the third embodiment is as follows.
An optical fiber in which 5-1 is coated on an optical fiber core 5-2 is prepared, and a part of the protective film (coating layer) 5-1 is peeled off. The method of peeling is described in Example 1 above. next,
As shown in FIG. 8B, an insulating substrate 5-3 having a V groove 5-3A for fixing an optical fiber is prepared. Next, as shown in FIG. 8C, a protective film (coating layer) 5-1 is formed.
The optical fiber core 5-2 from which is peeled is placed in the V-shaped groove 5-3A, and is heated and melted at about 100 ° C. with polyimide 5-4, and thermally cured at about 300 ° C. The melting of the polyimide is 50 ° C to 100 ° C, and the curing is 200 ° C to 400 ° C.
° C. Next, as shown in FIG. 8D, a groove 5-5 having a width of about 50 μm to 100 μm is formed by a dicing saw.
To form

Next, as shown in FIG. 9A, an ITO transparent electrode 5-7 is formed on the wall surface and the side surface by sputtering. In the normal sputtering, the ITO transparent electrode 5-7 is formed on the wall surface to a depth approximately equal to the groove width. Therefore, if the aspect ratio between the groove width and the depth is set to 5 or more, the IT
The O transparent electrode 5-7 does not short-circuit at the bottom of the groove 5-5. Further, since the core portion through which light passes is about 60 μm from the side of the optical fiber, the ITO transparent electrode 5-7 can be formed in the core portion. Optical fiber protective film (coating layer)
Since 5-1 and the fixing agent are metal or polyimide, the sputtering substrate temperature and the heat treatment temperature are 100
It is possible to use the temperature between 400C and 400C. Here, the substrate temperature 1
Forming an about 20 nm ITO transparent electrode 5-7 at 00 ° C.
Thereafter, heat treatment was performed at 350 ° C. The ITO film formed on the end face of the optical fiber had a transmittance of 98% or more in the communication wavelength band of 1.55 μm.

Next, as shown in FIG. 9B, a liquid crystal is filled. Here, a polymer network liquid crystal was filled. Next, as shown in FIG. 9C, the polymer network liquid crystal was cured by irradiating ultraviolet rays UV. As described in the first and second embodiments, the liquid crystal may be a cholesteric-nematic phase transition liquid crystal, a polymer dispersed liquid crystal, or a dynamic scattering liquid crystal.

The variable optical attenuator manufactured in the above steps is also shown in FIG.
It showed the same characteristics as. In the third embodiment, since there is no need to insert and fix an optical fiber and align the optical fiber as compared with the first embodiment, a variable optical attenuator can be realized more easily.

(Embodiment 4) In Embodiments 1 and 2, an optical element in which liquid crystal is filled between opposing optical fibers is shown.
In a fourth embodiment according to the present invention, formation of a light emitting element on an end face of one optical fiber will be described. That is, although a semiconductor laser and a light emitting diode are usually used as a light source for an optical fiber, a method of forming an electroluminescent (EL) element at the tip of the optical fiber as a low-speed light source will be described.

First, in the same manner as in the above embodiment, ITO serving as a lower electrode of EL is formed on the end face and side face of the fiber coated with polyimide and metal. The conditions for forming the ITO are the same as in the first and second embodiments. The transparent electrode is not limited to ITO, and a substrate temperature and a heat treatment temperature of 100 ° C. to 400 ° C. are optimal for a conventionally known transparent electrode such as In ₂ O ₃ , SnO ₂ , and ZnO.

There are various types of ELs. Old Mn of ZnS as a base material, Tb, a material obtained by adding emission center such as Sm, SiO ₂ and Ta ₂ 0 ₅ AC driving of the inorganic thin film EL double insulation structure sandwiching an insulating layer such as a transparent electrode DC-driven inorganic thin film EL with ZnS: Cu, Mn deposited directly on top of it, or AC-driven organic dispersed EL with a phosphor such as ZnS: Cu, Cl dispersed in an organic binder
Etc.

Also, there is electroluminescence using a Si fine particle thin film as a light emitting layer. Conventionally, a Si light emitting device has been manufactured by making single-crystal Si porous.
Recently, a light-emitting layer can be formed on a glass substrate by CVD or vapor deposition.

[0072] In addition, the new has the organic thin film EL composed of an organic luminescent layer typified by such A1q _3. Organic thin film EL
Has a modulation rate of several MHz, and is used for FTTH as a very inexpensive light source. Also, recently, the organic thin film EL is sometimes called an organic light emitting diode, which also falls within the scope of the present invention.

The formation temperature of these EL is from room temperature to 400
C. or so, and it is necessary to use the heat-resistant coated optical fiber of the present invention and the technique of forming ITO thereon.

The method for forming the electrode layer, the light emitting layer, and the like includes a vapor deposition method and a sputtering method, and a method using a solution-based material is also convenient. That is, for example, a first layer such as an electrode is formed by dipping in a solution relatively deeply to form a fiber (dip), and then as a second layer, for example, a solution-based material that becomes a light-emitting layer has a greater thickness. By immersing shallowly, it is possible to provide a region where the first layer is exposed far from the fiber tip and the electrode can be taken out, and a region where the two layers overlap. Further, by immersing the electrode material for the third layer, for example, further shallower than in the case of the two layers, it is possible to provide an electrode layer which is not directly connected to the first electrode and has a light emitting layer interposed therebetween. As described above, by gradually decreasing the depth of immersion in a solution material, a light emitting element having an EL layer on a fiber can be easily formed. This formation method can be applied not only to the case of three layers as described above, but also to the case of providing a hole / electron transport layer, a hole / electron injection layer, a buffer layer and the like on both sides or one side of the light emitting layer. It is clear.

FIGS. 10 (a), 10 (b) and 10 (c) show typical structures of main parts of the fiber type optical element of the fourth embodiment. Here, the structure of an organic thin film EL having Alq ₃ as a light emitting layer is shown as a typical EL. FIG. 10A is an external view,
FIG. 10B is a cross-sectional view taken along line AA ′ shown in FIG. 10A, FIG. 10C is a diagram showing a light emitting state, and 6-1 is a glass fiber (optical fiber). -2 is a protective film (coating layer) made of polyimide or metal, 6-3 is ITO
A transparent electrode, 6-4 is a layer containing an organic light emitting layer represented by Alq ₃ , 6-5 is a back electrode, 6-6 is a back extraction electrode,
6-7 is a light emitting state, and 6-8 is a core of an optical fiber. The upper electrode is taken out by bonding or using a prober. Although the organic light emitting layer is shown as a single organic thin film here, it may be a multilayer organic thin film. For the back electrode, Mg, In, or the like is used in addition to Al.

When a voltage is applied between the ITO electrode on the side of the optical fiber and the back electrode, the light emitting layer formed at the tip of the optical fiber emits light, and the light enters the core of the optical fiber and is transmitted. The response speed of EL is several MHz, and high-speed transmission like a semiconductor laser is impossible, but it is effective as an inexpensive and small light source for a low-speed optical fiber network of an access system.

Fifth Embodiment In the fourth embodiment, the light emitting device in which the EL layer is formed on the transparent electrode on the end face of the optical fiber has been described. Here, the structure of the device having the surface emitting laser or the surface type detector attached thereto is described. The manufacturing method will be described with reference to FIGS. 11 (a), (b) and (c). Here, the structure of an organic thin film EL having Alq ₃ as a light emitting layer is shown as a typical EL.

FIG. 11 is a diagram showing the structure of an element in which a surface emitting laser and a surface PD are attached to the tip of an optical fiber according to the fifth embodiment of the present invention, FIG. 11 (a) is an external view, and FIG. 11A is a cross-sectional view taken along line AA ′ in FIG.
(c) is a diagram showing a light emitting state. In FIG. 11, 7-
1 is an optical fiber (glass fiber), 7-2 is an ITO transparent electrode, 7-3 is a core of the optical fiber 7-1, 7-4 is a protective film (coating layer) made of polyimide or metal, 7-5.
Is an extraction electrode from the side of the optical fiber, 7-6 is a light emitting region of the surface emitting laser, 7-7 is an extraction electrode on the back surface of the surface emitting laser, 7-8 is a substrate of the surface emitting laser, and 7-9 is a surface emitting laser. Solder bumps or conductive adhesives connected to the electrodes on the surface of the device.

Conventionally, in order to couple a semiconductor laser, a detector and an optical fiber, the semiconductor laser is mounted on a dedicated mount, an electrode is taken out by bonding, and alignment is performed with the optical fiber to couple light. For this reason, it was difficult to reduce the size of the module, and further, labor was required for alignment.

In the present invention, a transparent electrode is formed on the end face and side face of an optical fiber, and the end face of the optical fiber is used as a mount for a surface emitting laser and a detector. Since the transparent electrode is formed on the end face and the side face of the optical fiber, the surface element can be attached to the end face and the electrode can be taken out from the side face of the optical fiber.

As shown in FIGS. 11 (a) and 11 (b), solder bumps or conductive paste (conductive adhesive 7-9) are applied to the electrodes on the surface of the chip (substrate) of the surface emitting laser, and the ITO transparent electrodes are formed. 7-2 is attached to the tip of the optical fiber 7-1 formed on the end face and side face. In the case of solder, bonding is performed by heating from 100 ° C. to 200 ° C., and in the case of conductive paste, bonding is performed at a temperature of several tens to 200 ° C. Alternatively, an electrode is formed such that the electrode on the light emitting side (surface side) of the surface emitting laser is higher than the light emitting layer, and the optical fiber 7
The transparent adhesive is filled between the optical fiber 7-1 and the surface emitting laser or the surface detector, and is bonded by heating.

As another attaching method, there is a method using a transparent conductive coating material. That is, IT
Fiber 7-coated with a transparent electrode such as O
The transparent electrode material is applied and filled between the substrate 2 and the substrate 7-8 of the surface-emitting laser, including the light-emitting region 7-6 of the surface-emitting laser, and only heat treatment at 200 to 400 ° C. or vacuuming is performed. Baking and bonding together. According to this method, fine mounting and filling of the solder bumps and the transparent adhesive with high precision are not required, and the bonding process becomes easier.

At this time, the alignment is performed so that the light emitting region 7-6 of the surface emitting laser and the core 7-3 of the optical fiber 7-1 coincide with each other. The size of the surface emitting laser is about 250 μm square, the light emitting area 7-6 is 10 μm to 50 μm, the extraction electrode can be arranged within 100 μm square, and the end face of the optical fiber 7-1 is usually 125 μm φ, which is sufficient. It can be attached to the end face region of the optical fiber 7-1.

Further, the core of the optical fiber is 50-1.
When a multi-mode fiber as large as 200 μm is used, it becomes easier to mount a surface emitting laser or the like. That is, the core of the optical fiber is 50 to 12
If it is 00 μm, a surface emitting laser or the like can be easily mounted. In addition, the end face of the fiber coated with a transparent electrode such as ITO is processed in advance to be a non-flat structure, for example, the core region is depressed, so that mounting and bonding of the surface emitting laser are facilitated and appropriate. It can be easily mounted at a suitable position.

The electrode 7-5 attached to the side of the optical fiber 7-1
The surface emitting laser can emit light by flowing a current between the electrodes 7-7 attached to the back surface of the surface emitting laser, and light can be output to the core 7-3 of the optical fiber 7-1.
Thus, a small-sized module can be easily manufactured only by attaching the surface emitting laser chip (substrate) to the tip of the optical fiber 7-1.

Further, by using a surface emitting laser array and an optical fiber array, arraying is possible. Here, only the surface emitting laser has been described, but even if the surface type PD is attached to the tip of the optical fiber 7-1, it is small in size and size.
There is an advantage of arraying.

As described above, the invention made by the present inventor is:
Although specifically described based on the embodiment (example),
The present invention is not limited to the above-described embodiment (example), and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0088]

The effects obtained by the invention disclosed in the present application will be briefly described as follows.

According to the present invention, when optical fibers are opposed to each other and a material having an optical modulation and electro-optic effect is inserted between the optical fibers, the optical axes of the optical fibers are easily made to coincide with each other. Can be easily done.

Further, a light source / detector can be easily manufactured on the end face of the optical fiber. Further, an optical device in which transparent electrodes having high transmittance are formed on the end face and side face of the optical fiber can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of a fiber optical device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of manufacturing the fiber-type optical device shown in FIG.

FIG. 3 is a diagram for explaining a method of manufacturing the fiber-type optical device shown in FIG.

FIG. 4 is a transmission spectrum diagram showing a transmittance of a transparent electrode in a communication wavelength band, where (a) is a transmission spectrum before annealing,
(B) 40 nm I annealed at 350 ° C. for 150 minutes
3 shows a transmission spectrum of TO.

FIG. 5 is a diagram illustrating characteristics of an optical attenuator that is a fiber-type optical element according to the first embodiment.

FIG. 6 is a view illustrating a process of manufacturing the optical polarization control element according to the second embodiment of the present invention.

FIG. 7 is a diagram illustrating a manufacturing process of the optical polarization control element according to the second embodiment.

FIG. 8 is a diagram showing a manufacturing process of a fiber optical device according to a third embodiment of the present invention.

FIG. 9 is a view showing a manufacturing process of a fiber optical device according to a third embodiment of the present invention.

FIG. 10 is a diagram showing a typical structure of a main part of a fiber optical device according to a fourth embodiment of the present invention.

FIG. 11 is a view showing the structure of an element in which a surface emitting laser and a surface PD are attached to the tip of an optical fiber according to a fifth embodiment of the present invention.

[Explanation of symbols]

1-1: Optical fiber core wire (for example, glass fiber),
1-2: Optical fiber, 1-2A: Protective film (coating layer), 1-
3 ITO transparent electrode 1-4 Glass splice holder 1-5 Micro glass cavities 1-5A V
Groove, 1-5A ... V groove, 1-6 ... Splice lid, 1-7 ...
Metal plate for fiber holding, 1-8: Material having electro-optical effect or light modulation effect, 1-8A: Gap, 1-9: Extraction electrode, 1-10: Insulating film, 4
-1: polyimide alignment film, 4-2: rubbing roll, 4-
3: Marker indicating rubbing direction, 4-4: Nematic liquid crystal, 5-1: Protective film (coating layer), 5-2: Optical fiber core, 5-3: Insulating substrate, 5-3A: V groove, 5-4: polyimide, 5-5: groove, 5-6: dicing saw blade, 5-7: ITO transparent electrode, 5-8: liquid crystal, 5-9: extraction electrode, 6-1: glass optical fiber, 6-2: Protective film (coating layer), 6-3: ITO transparent electrode, 6-4: Layer containing organic light emitting layer, 6-5: Back electrode, 6-6: Back extraction electrode, 6-7 ... Light emitting state, 6-8: Optical fiber core, 7
-1: Glass fiber, 7-2: ITO transparent electrode, 7-3
... core of optical fiber, 7-4 ... protective film (coating layer), 7-5
... Electrode taken out from the side of optical fiber, 7-6 ... Emission area of surface emitting laser, 7-7 ... Electrode on the back surface of surface emitting laser, 7-8 ... Surface emitting laser substrate, 7-9 ... Solder bump or conductive Adhesive.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/065 G02F 1/065 1/13 505 1/13 505 F-term (Reference) 2H037 BA01 BA11 BA35 CA09 DA03 DA04 DA06 DA12 DA15 2H038 AA35 BA23 BA30 2H050 BB06W BB26W 2H079 AA02 AA12 BA01 BA02 BA03 CA04 CA05 CA07 CA08 DA07 DA08 EA09 EB12 EB17 GA07 KA11 2H088 EA45 EA47 FA08 FA18 GA02 GA03 GA04 GA10 HA04

Claims (13)

[Claims] 1. A fiber type optical element, wherein the fiber coating has a heat resistance of 100 ° C. or more, and the transparent electrode comprises an optical fiber provided on an end face and a side face. 2. An end face of the optical fiber, wherein a pair of optical fibers having the transparent electrode provided on an end face and a side face face each other with an interval between the end faces, and are arranged such that their optical axes coincide with each other. 2. The gap between them is filled or inserted with a material or an element having an electro-optic effect and a light modulation effect to control the intensity and polarization of the light and to select the wavelength. Fiber type optical element. 3. The one optical fiber is fixed to a substrate, a vertical groove is provided in the optical fiber, a transparent electrode is provided on a wall surface of the groove, and the groove has an electro-optic effect and a light modulation effect. 2. The fiber type optical element according to claim 1, wherein a material or an element is filled or inserted to control the intensity and polarization of the light or to select a wavelength. 4. The material having the electro-optic effect and the light modulation effect is any one of a nematic liquid crystal, a polymer dispersed liquid crystal, a polymer network liquid crystal, a ferroelectric liquid crystal, a cholesteric-nematic phase transition liquid crystal, and a dynamic scattering liquid crystal. 3. An element which is one or an electrochromic material and has the electro-optic effect and the light modulation effect is a semiconductor surface light modulator or an electro-optic crystal surface light modulator. Item 4. A fiber type optical element according to item 3. 5. The apparatus according to claim 1, wherein one of an electroluminescence element, a surface emitting laser, and a surface detector is provided on the transparent electrode on the end face of the optical fiber.
2. The fiber-type optical element according to item 1. 6. The electroluminescence device according to claim 1, wherein the electroluminescence device is an organic thin film electroluminescence, an inorganic thin film electroluminescence obtained by doping ZnS or ZnSe with a light emitting element,
7. The fiber-type optical device according to claim 6, wherein the fiber-type optical device is made of one of an organic dispersion type electroluminescence obtained by mixing a ZnS phosphor in a binder and an electroluminescence mainly composed of an ultrafine Si film. 7. The transparent electrode according to claim 1, wherein the transparent electrode is made of one of indium tin oxide (ITO), In ₂ O ₃ , SnO ₂ , and ZnO.
The fiber type optical element according to any one of the above. 8. The fiber type optical element according to claim 1, wherein the coating of the optical fiber is made of metal or polyimide. 9. A method for manufacturing a fiber-type optical device, comprising:
Indium tin oxide (I) is applied to the end face and side face of the optical fiber.
TO), any one of In ₂ O ₃ , SnO ₂ , and ZnO
A method for manufacturing a fiber-type optical element, wherein a transparent electrode is formed by sputtering or evaporating two materials. 10. A pair of optical fibers each having the transparent electrode formed on an end face and a side face are opposed to each other with an interval between the end faces, and arranged so that their optical axes coincide with each other. The method according to claim 9, wherein a material or element having an electro-optic effect or a light modulation effect is filled or inserted into the gap between them. 11. A jig for arranging the optical fibers so as to face each other and align the optical axes is one of a V-groove, an optical fiber connecting splice, an optical connector comprising a ferrule and a sleeve, and a microcavity. The method for manufacturing a fiber-type optical device according to claim 10, comprising: 12. A method for forming a transparent electrode on the end face and the side face of the optical fiber is any one of a sputtering method, a vapor deposition method, and a coating method, and a temperature at which the transparent electrode is formed or a heat treatment temperature is 100. The method for producing a fiber-type optical element according to claim 10, wherein the temperature is in the range of from 400C to 400C. 13. An optical fiber is fixed to a substrate, a groove perpendicular to the optical fiber is formed, a transparent electrode is formed on a wall surface of the groove, and the groove has an electro-optic effect and a light modulation effect. A method for producing a fiber-type optical element in which a material or an element is filled or inserted, wherein the material in which the optical fiber is fixed to the substrate is polyimide, and the polyimide is melted and cured at a temperature of 100 ° C to 400 ° C. A method for manufacturing a fiber-type optical element, which is a feature of the present invention.