JP2007072112A - Optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device capable of ensuring an interaction length between the light made incident to the optical device and a carbon nanotube long. <P>SOLUTION: The optical device 1 comprises: a waveguide 131; and a region (CNT region) 14 which is disposed along an optical axis of the waveguide 131 and contains a carbon nanotube disposed near the waveguide 131. The CNT region 14 is allowed to come directly into contact with the upper surface of the waveguide 131. In the optical device 1, an evanescent wave from the waveguide 131 oozes into the CNT region 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical device provided with a layer containing carbon nanotubes.

In recent years, carbon nanotubes (CNT), especially single-walled carbon nanotubes (SWNT), have attracted attention in the field of optical devices because of their saturable absorption characteristics and high-speed response characteristics. For example, the saturable absorption characteristics of carbon nanotubes are applied to optical noise suppressors, passive mode-locked fiber lasers, Q-switched fiber lasers, and the like.
Conventionally, as an optical device using carbon nanotubes, a glass substrate coated with carbon nanotubes has been used. This optical device is disposed in the optical path so that the surface of the glass substrate is perpendicular to the optical axis (see, for example, Patent Document 1).
In addition, an optical fiber (optical device) in which a region containing carbon nanotubes (herein, a layer containing carbon nanotubes) is provided on the end surface on the light emitting side has been developed (see, for example, Patent Document 1).

JP 2004-280028 A

However, the technique of Patent Document 1 has room for improvement in the following points.
In order to sufficiently generate the interaction between the light incident on the optical device and the carbon nanotube and to obtain an optical device having a desired performance (for example, a desired saturable absorption characteristic), the light incident on the optical device and the carbon It is necessary to increase the interaction length with the nanotube.
In the optical device of Patent Document 1, the layer containing carbon nanotubes is arranged perpendicular to the optical axis. Therefore, in order to increase the interaction length between the light incident on the optical device and the carbon nanotubes, It is necessary to increase the thickness of the layer containing carbon nanotubes.
However, in the conventional optical device, increasing the thickness of the layer containing the carbon nanotube has a limit from the viewpoint of transparency.

  The objective of this invention is providing the technique which can obtain the optical device which can ensure long interaction length with the light which injected into the optical device, and a carbon nanotube.

  The present inventors have found that an interaction occurs between the evanescent wave that oozes from the waveguide and the carbon nanotube. This makes it possible to employ a novel configuration in which a region containing a carbon nanotube is provided near the waveguide along the optical axis of the waveguide. That is, according to the present invention, it is possible to provide an optical device having a configuration completely different from a conventional optical device in which a layer having carbon nanotubes is formed perpendicular to the optical axis.

According to the present invention, there is provided an optical device comprising: a waveguide; and a region that is disposed along the optical axis of the waveguide and includes a carbon nanotube provided in the vicinity of the waveguide. Provided.
Here, in the present invention, the vicinity of the waveguide means a region where an evanescent wave of light propagating through the waveguide exudes.

  In the conventional optical device, the performance of the optical device is determined by the interaction between the light passing through the waveguide and the carbon nanotube. However, the optical device of the present invention has an evanescent wave that oozes out of the waveguide. The performance of the optical device is determined by the interaction with the carbon nanotube.

In the present invention, the carbon nanotube-containing region is disposed along the optical axis of the waveguide, and is provided so as not to intersect the optical axis of the waveguide. That is, in the present invention, since the region containing the carbon nanotube is not provided perpendicular to the optical axis as in the conventional case, the interaction length between the incident light incident on the waveguide and the carbon nanotube (in other words, Further, even if the interaction length between the evanescent wave and the carbon nanotube is increased, the light transmittance does not deteriorate.
As a result, in the optical device of the present invention, the interaction length between the evanescent wave and the carbon nanotube can be ensured long, and the interaction between the light incident on the optical device and the carbon nanotube is sufficiently generated. Thus, an optical device having a desired performance can be obtained.

  Furthermore, in the present invention, the performance of the optical device can be determined by the interaction between the evanescent wave that oozes out from the waveguide and the carbon nanotube. Since the amount of evanescent waves that ooze out from the waveguide is very small, when manufacturing an optical device, for example, there is an error in the length dimension of the region containing carbon nanotubes (the interaction length between the evanescent wave and the carbon nanotubes). Even if it occurs, it is considered that the performance of the optical device is not greatly affected. Therefore, in the present invention, an optical device excellent in manufacturing stability can be provided.

  In the present invention, since the region containing the carbon nanotube is provided along the optical axis, the evanescent wave oozes out into the region containing the carbon nanotube, but the intensity of the evanescent wave is It is weaker than light propagating in the waveguide. Therefore, it is possible to prevent the carbon nanotube from being deteriorated by light.

At this time, the waveguide has a substrate and a cladding layer formed on the substrate, and is provided on the cladding layer and has a refractive index higher than that of the cladding layer, and the optical axis of the waveguide. And a region containing carbon nanotubes provided in the vicinity of the waveguide.
According to such a configuration, the clad layer is provided on the substrate, and the waveguide is provided on the clad layer. In the optical device having this configuration, the clad layer and the substrate can be shared, and another waveguide can be formed on the clad layer, and the monolithic structure can be adopted to integrate the optical device. .

Furthermore, the present invention is configured to include an optical fiber, and the optical fiber includes a core portion that constitutes the waveguide, a clad portion provided on an outer peripheral side of the core portion, and an optical axis of the core portion. And a region containing carbon nanotubes provided in the vicinity of the core portion.
At this time, examples of the structure of the optical fiber include the following structures (i) to (iv).
(I) The clad portion is formed with a cutout portion cut out along the optical axis of the core portion, and the cutout portion is located in the vicinity of the core portion. And a region containing the carbon nanotubes.
In the optical fiber having such a structure, a part of the outer peripheral surface of the clad portion of the conventional optical fiber is cut out to form a cutout portion located in the vicinity of the core portion, and the carbon nanotube is placed on the cutout portion. What is necessary is just to provide the area | region to contain.

(Ii) The clad part is formed in the vicinity of the core part and has a hole extending along the optical axis of the core part, and a region containing the carbon nanotube is provided inside the hole. Structure.
An optical fiber having such a structure can be manufactured, for example, by providing a region containing a carbon nanotube in an air hole of a photonic crystal optical fiber.

(Iii) The core part has a structure in which a hole extending along the optical axis of the core part is formed in the center part, and a region containing the carbon nanotube is provided in the hole.

(Iv) The clad portion has a taper portion that expands after its diameter gradually decreases along the optical axis of the optical fiber, and the region containing the carbon nanotube has at least the smallest diameter of the taper portion Structure provided to cover the outer peripheral surface of the part.

  Furthermore, in the present invention, the optical device may be an optical switch, and may include a second waveguide disposed in a positional relationship where an optical intersection occurs with respect to a part of the waveguide. .

Here, in the present invention, the optical switch is a concept including not only one that turns ON / OFF the emitted light but also one that changes the phase of the emitted light.
A region containing carbon nanotubes is provided in the vicinity of the above-described waveguide (hereinafter referred to as the first waveguide), and the first waveguide is formed according to the intensity of light passing through the first waveguide. The absorptance of light passing through changes. When a change occurs in the light absorption rate, the phase of the light passing through the first waveguide also changes.
Since the second waveguide is disposed in a positional relationship where an optical crossing occurs with respect to the first waveguide, the second waveguide is changed according to a change in the phase of light passing through the first waveguide. Light emitted from the waveguide is affected.

  At this time, the end portion on the light exit side of the second waveguide is connected to the end portion on the light exit side of the waveguide, and the end portion on the light incident side of the second waveguide is Connected to the light incident side end of the waveguide, the second waveguide and an incident side waveguide for entering light into the waveguide, and the second waveguide and the waveguide from the waveguide It is preferable that an exit-side waveguide that emits light is provided.

In the optical switch having this configuration, light from the incident-side waveguide is branched into the waveguide (hereinafter referred to as the first waveguide) and the second waveguide.
As described above, the phase of light passing through the first waveguide changes depending on whether the intensity of light incident on the first waveguide is weak or strong.
For example, when the intensity of light incident on the first waveguide is weak, a large phase change, for example, the phase changes by 180 °. In this case, the phase of the light from the first waveguide and the phase of the light from the second waveguide are shifted by 180 °, so that they cancel each other and the light propagates in the output-side waveguide. Will not do.
On the other hand, when the intensity of the light incident on the first waveguide is strong, a large phase change does not occur in the light in the first waveguide, and the light from the first waveguide and the second The light from the waveguide does not cancel each other. Therefore, the light from the first waveguide and the light from the second waveguide are combined, and the light propagates through the emission-side waveguide.

  ADVANTAGE OF THE INVENTION According to this invention, the technique of obtaining the optical device which can ensure long interaction length with the light which injected into the optical device and a carbon nanotube is provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In all the drawings, similar constituent elements are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
As described above, the optical device according to the present invention utilizes the interaction between the evanescent wave that oozes out of the waveguide and the carbon nanotube.
Here, the amount of the evanescent wave that oozes out from the waveguide is very small. Therefore, it is necessary to increase the interaction length between the evanescent wave and the carbon nanotube. In the present embodiment, by providing the CNT region along the optical axis of the waveguide, it is possible to ensure a long interaction length and provide an optical device having desired characteristics.

(First embodiment)
1 and 2 show an optical device 1 according to the present embodiment.
The optical device 1 includes a waveguide 131,
A region 14 disposed along the optical axis of the waveguide 131 and containing carbon nanotubes provided in the vicinity of the waveguide 131;
It is what has.
The optical device 1 will be described in detail below.

The optical device 1 has a substantially rectangular planar shape, and includes a substrate 11, a cladding layer 12, a core layer 13, and a region (hereinafter referred to as a CNT region) 14 containing carbon nanotubes.
The substrate 11 is a silicon single crystal substrate.
The clad layer 12 is provided on the substrate 11 and is a layer made of SiO ₂ .
The core layer 13 is provided on the cladding layer 12 and is a layer in which Ge is added to a layer containing SiO ₂ . The core layer 13 has a higher refractive index than the cladding layer 12.
Further, a waveguide 131 is formed in the core layer 13.
The waveguide 131 is in a state of being embedded in a portion 132 other than the waveguide 131 of the core layer 13 (embedded waveguide). The surface of the waveguide 131 and the surface of the other portion 132 are on the same plane.
The waveguide 131 extends along the longitudinal direction of the optical device 1. The waveguide 131 has a refractive index higher than that of the cladding layer 12 and is higher than the refractive index of the other portion 132 of the core layer 13.

The CNT region 14 is provided on the core layer 13, and the CNT region 14 is in direct contact with the upper surface of the waveguide 131. The CNT region 14 covers the surface of the waveguide 131 and the surface of the portion of the other portion 132 adjacent to the waveguide 131.
The CNT region 14 extends along the optical axis of the waveguide 131. Here, the CNT region 14 may be formed so as to cover the entire surface of the waveguide 131 along the entire length of the waveguide 131, or may be formed so as to cover only a part of the surface of the waveguide 131. May be. The length dimension of the CNT region 14 along the waveguide 131 can be set as appropriate according to the application of the optical device 1, the ratio of the evanescent wave oozing from the waveguide 131, and the like.
Furthermore, the thickness of the CNT region 14 depends on the length of the CNT region 14 along the waveguide 131, the ratio of the evanescent wave oozing from the waveguide 131, the distance the evanescent wave oozes from the waveguide 131, and the like. May be set as appropriate.
In general, it is said that the distance at which the evanescent wave from the waveguide 131 bleeds is several tens of μm. In the case where it is difficult to form a thick CNT region 14 and the thickness of the CNT region 14 is several hundred nm, it is necessary to ensure a long length along the waveguide 131 of the CNT region 14. The action of CNT can be reliably applied to the light passing through the waveguide 131.

For example, as shown in FIG. 15, the carbon nanotubes included in the CNT region 14 have saturable absorption characteristics at 1200 nm to 1700 nm.
The carbon nanotubes contained in the CNT region 14 are preferably single-walled carbon nanotubes (SWCNT).
Furthermore, the carbon nanotubes included in the CNT region 14 are preferably arranged so that the axis thereof is perpendicular to the optical axis of the waveguide 131.
Further, the carbon nanotubes may be placed on the waveguide 131 so that the axis of the carbon nanotubes included in the CNT region 14 is perpendicular to the surface of the waveguide 131.
The absorptance of the CNT region 14 changes depending on the angle formed by the axis of the carbon nanotube and the incident optical field, and becomes maximum when the axis of the carbon nanotube and the incident optical field are parallel, and when the axis is vertical. Minimal. Therefore, it is preferable that the axis of the carbon nanotube is perpendicular to the optical axis of the waveguide 131 or the axis of the carbon nanotube is perpendicular to the waveguide 131.

The optical device 1 having such a structure is manufactured as follows.
As shown in FIG. 3, SiO ₂ particles constituting the cladding layer 12 are deposited on the substrate 11 by, for example, a flame deposition method. After that, heating is performed to melt the SiO ₂ fine particles and to make them transparent.
Next, fine particles of SiO ₂ —GeO ₂ constituting the core layer 13 are deposited on the cladding layer 12 by the same flame deposition method. After that, it is heated to melt the SiO ₂ —GeO ₂ fine particles and to make them transparent.
In addition, the lamination | stacking method of the cladding layer 12 and the core layer 13 is not restricted to a flame deposition method.
Thereafter, the surface of the core layer 13 is irradiated with ultraviolet rays according to the pattern of the waveguide 131. For example, a stacked body in which a clad layer 12 and a core layer 13 are provided on a substrate 11 is placed on a moving stage, and the moving stage is driven while irradiating ultraviolet rays.
Thus, by irradiating with ultraviolet rays, the refractive index of the ultraviolet irradiation region of the core layer 13 changes, and the waveguide 131 is formed.
Here, the clad layer 12 and the core layer 13 are laminated by the flame deposition method, and then the waveguide 131 is formed by irradiating ultraviolet rays. However, the method of forming the waveguide 131 is not limited to this.
For example, after laminating a clad layer and a core layer by a flame deposition method, only the portion constituting the waveguide is left and the core layer is etched. Thereafter, the side surface of the waveguide may be embedded with the same material as the cladding layer.

Thereafter, the CNT region 14 is provided on the waveguide 131.
For example, the carbon nanotubes are uniformly dispersed in a solvent such as alcohol, dichloroethane, dimethylformamide, and the dispersion is prepared. This dispersion is sprayed and applied onto the waveguide 131.
Note that the method of forming the CNT region 14 is not limited to the method described above.
For example, when the carbon nanotubes included in the CNT region 14 are arranged so that the axis thereof is perpendicular to the optical axis of the waveguide 131, the carbon nanotubes are dissolved in a polymer or glass, the polymer or glass is pulled, and the CNT region is 14 is formed. Thereby, the axis of the carbon nanotube can be arranged perpendicular to the optical axis of the waveguide 131.
Further, when the carbon nanotubes are arranged on the waveguide 131 so that the axis of the carbon nanotubes included in the CNT region 14 is perpendicular to the waveguide 131, the CVD method is used to arrange the carbon nanotubes. Form.

In the optical device 1 having such a structure, the evanescent wave from the waveguide 131 oozes out into the CNT region 14 and receives the saturable absorption characteristic of the CNT region 14. For example, when the intensity of light passing through the waveguide 131 is weak, the evanescent wave from the waveguide 131 oozes out into the CNT region 14 and is absorbed by the CNT region 14.
On the other hand, when the intensity of light passing through the waveguide 131 is strong, the evanescent wave from the waveguide 131 oozes out into the CNT region 14 but is hardly absorbed by the CNT region 14 and is emitted from the optical device 1. Will be.
The optical device 1 as described above can be mounted on, for example, a mode-locked laser device or the like. When mounted on a mode-locked laser device, the length of the CNT region 14 along the optical axis of the waveguide 131 is preferably about 1 mm to 50 mm.

Next, the effect of the optical device 1 of this embodiment is demonstrated.
Since the CNT region 14 is provided along the optical axis of the waveguide 131 and is not provided perpendicular to the optical axis as in the prior art, the incident light incident on the waveguide 131 and the CNT region 14 are provided. Even if the interaction length (in other words, the interaction length between the evanescent wave and the carbon nanotube) is increased, the light transmittance does not deteriorate.
Thereby, in the present embodiment, the interaction length between the evanescent wave and the carbon nanotube can be increased, and the interaction between the evanescent wave of the incident light and the CNT region 14 is sufficiently generated, so that the desired length can be obtained. The optical device 1 having the performance can be obtained.

  In the present embodiment, since the CNT region 14 is directly formed on the waveguide 131, the evanescent wave leaks from the waveguide 131 into the CNT region 14 with certainty. Thereby, the interaction between the carbon nanotube and the evanescent wave can be surely generated.

  Furthermore, in this embodiment, the performance of the optical device 1 is determined by the interaction between the evanescent wave that oozes out from the waveguide 131 and the carbon nanotube. Since the amount of evanescent wave that oozes out from the waveguide 131 is very small, an error occurs in the length dimension of the CNT region 14 (interaction length between the evanescent wave and the carbon nanotube) when the optical device 1 is manufactured. However, it is considered that the performance of the optical device 1 is not greatly affected. Therefore, in this embodiment, the optical device 1 excellent in manufacturing stability can be provided.

Further, in the conventional optical device such as Patent Document 1, since the layer containing carbon nanotubes is provided perpendicular to the optical axis, the carbon nanotubes deteriorate when transmitting light with high intensity. There was a possibility.
On the other hand, in this embodiment, since the CNT region 14 is provided along the optical axis, evanescent waves ooze out from the CNT region 14. Since the intensity of the evanescent wave is weaker than the light propagating through the waveguide 131, the carbon nanotube can be prevented from being deteriorated by the light.

(Second embodiment)
FIG. 4 shows an optical device 2 according to the second embodiment.
The optical device 2 includes a substrate 11 and a cladding layer 12 similar to those in the first embodiment.
A waveguide 23 having a substantially trapezoidal cross section is provided on the cladding layer 12.
The waveguide 23 protrudes upward from the surface of the cladding layer 12 and has a so-called ridge shape.
The waveguide 23 is a layer containing SiO ₂ and Ge as in the above embodiment, and has a refractive index higher than that of the cladding layer 12.
On the waveguide 23, the CNT region 14 similar to that of the above embodiment is formed. The CNT region 14 extends along the optical axis of the waveguide 23 and integrally covers the upper surface and side surfaces of the waveguide 23.
The optical device 2 having such a structure is manufactured as follows.
Similar to the above-described embodiment, the clad layer 12 is provided on the substrate 11, and, similarly to the above-described embodiment, a layer (not shown) containing SiO ₂ and Ge so as to cover substantially the entire surface of the clad layer 12. ). Then, masking is performed on this layer, and unnecessary portions (portions other than the portion that becomes the waveguide 23) are selectively removed. As a result, the waveguide 23 is formed.
Thereafter, the CNT region 14 is provided on the waveguide 23. The CNT region 14 can be provided by the same method as in the above embodiment.

Such an optical device 2 has the following effects in addition to the same effects as the optical device 1 of the above embodiment.
The CNT region 14 is provided so as to cover not only the upper surface of the waveguide 23 but also the side surfaces. Therefore, the evanescent wave from the upper surface and the side surface of the waveguide 23 oozes out into the CNT region 14, and the amount of the evanescent wave oozing out into the CNT region 14 can be increased.

  Furthermore, since the evanescent wave from the upper surface and the side surface of the waveguide 23 oozes out into the CNT region 14, the interaction between the evanescent wave and the carbon nanotube can be reliably generated. Therefore, the optical device 2 with stable performance can be manufactured.

(Third embodiment)
The optical device 3 according to the third embodiment will be described with reference to FIG.
The optical device 3 includes a substrate 11 and a clad layer 12 similar to those in the above embodiments.
On the clad layer 12, a core layer 33 having a refractive index higher than that of the clad layer 12 is formed.
The core layer 33 is obtained by adding Ge to a layer containing SiO ₂ , and includes a base 331 that covers the upper surface of the cladding layer 12 and a waveguide 332 provided on the base 331.
The waveguide 332 has a substantially trapezoidal cross section and is formed so as to protrude upward from the base 331.
On the waveguide 332, the CNT region 14 similar to that in each of the above embodiments is directly provided. The CNT region 14 extends along the optical axis of the waveguide 332 and integrally covers the upper surface and side surfaces of the waveguide 332.
When manufacturing the optical device 3, a layer (not shown) containing SiO ₂ and Ge is provided so as to cover substantially the entire surface of the cladding layer 12. Then, this layer is masked and etched. Etching is terminated when the thickness of the portion where the mask is not applied reaches a predetermined thickness.
In other respects, it can be manufactured by a method substantially similar to that of the second embodiment.
Such an optical device 3 has the same effect as the optical device 2 of the second embodiment.

(Fourth embodiment)
The optical device 4 according to the fourth embodiment will be described with reference to FIGS.
FIG. 6 is a perspective view showing the optical device 4 of the present embodiment, and FIG. 7 is a cross-sectional view of the optical device 4 of the present embodiment in the optical axis direction.
The optical device 4 is an optical fiber, and includes a core portion 41 and a clad portion 42 that is provided on the outer peripheral side of the core portion 41 and covers the outer periphery of the core portion 41.
The core portion 41 extends in a long shape and becomes a waveguide. The core portion 41 has a substantially circular cross section.
The clad portion 42 covers the outer periphery of the core portion 41 and extends along the core portion 41.
A flat surface portion (notch portion) 421 extending along the optical axis direction of the core portion 41 is formed on at least a part of the outer peripheral portion of the clad portion 42. That is, the cross-sectional shape of the cladding part 42 is a substantially semicircular shape.
The flat portion 421 can be formed by cutting out at least a part of the outer peripheral surface of the clad portion 42 having a substantially circular cross section along the optical axis of the core portion 41.
As shown in FIG. 7, the flat portion 421 may be formed on a part of the cladding portion 42 or may be formed over the entire length of the cladding portion 42.

In the cross section of the clad part 42 (cross section orthogonal to the optical axis of the core part 41), the distance L1 from the flat part 421 to the core part 41 is the distance from the outer peripheral surface of the clad part 42 other than the flat part 421 to the core part 41. Shorter than L2.
Further, the flat surface portion 421 is in the vicinity of the core portion 41, and the distance L1 from the flat surface portion 421 to the core portion 41 is shorter than the distance that the evanescent wave from the core portion 41 oozes out.
On such a plane portion 421, the CNT region 14 similar to that in each of the above embodiments is formed. The CNT region 14 is provided along the optical axis of the core portion 41.
In the optical device 4 described above, the evanescent wave of light propagating in the core portion 41 oozes out into the CNT region 14 on the flat portion 421.

Next, functions and effects of the optical device 4 of the present embodiment will be described.
Since the CNT region 14 is provided along the optical axis of the core portion 41 that is a waveguide, and is not provided perpendicular to the optical axis as in the prior art, the incident light incident on the core portion 41 and Even if the interaction length with the CNT region 14 (in other words, the interaction length between the evanescent wave and the carbon nanotube) is increased, the light transmittance does not deteriorate.
Thereby, the interaction between the evanescent wave of the light incident on the optical device 4 and the CNT region 14 is generated, and the optical device 4 having a desired performance can be provided.
Furthermore, in the optical device 4 of this embodiment, a clad portion of a conventional general circular optical fiber having a circular cross section is cut out to form a flat portion 421, and the CNT region 14 is provided on the flat portion 421. That's fine. Since the optical device 4 can be manufactured using a conventional optical fiber, an increase in manufacturing cost can be prevented.

  Furthermore, since the evanescent wave that oozes out from the core portion 41 is very small, when manufacturing the optical device 4, for example, the length dimension of the CNT region 14 (the interaction length between the evanescent wave and the carbon nanotube) is an error. Even if this occurs, it is considered that the performance of the optical device 4 is not greatly affected. Therefore, in this embodiment, the optical device 4 excellent in manufacturing stability can be provided.

  In the present embodiment, since the CNT region 14 is provided along the optical axis of the core portion 41, the evanescent wave oozes out from the CNT region 14. Since the intensity of the evanescent wave is weaker than the light propagating through the core portion 41, the carbon nanotube can be prevented from being deteriorated by the light.

(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to FIG.
The optical device 5 of this embodiment is an optical fiber using a photonic crystal optical fiber.
The optical device 5 has a core part 51 that constitutes a waveguide, and a clad part 52 provided on the outer periphery of the core part 51.
In this embodiment, the core part 51 and the clad part 52 are made of the same material, and the part surrounded by the plurality of holes 521 formed in the clad part 52 is the core part 51.
Here, only four holes 521 surrounding the core part 51 are shown in the figure, but a large number of holes may be further formed on the outer peripheral side of the hole surrounding the core part 51 of the cladding part 52.
The hole 521 extends along the optical axis of the core portion 51 and is disposed substantially parallel to the core portion 51.
Among the plurality of holes 521, the inside of the hole 521 which is located in the vicinity of the core part 51 and is formed so as to surround the core part 51 is filled with CNTs, and the CNT region 14 is provided.
Although the hole 521 is provided along the entire length of the core portion 51, the CNT region 14 may be provided only in a part of the hole 521, and is provided so as to completely fill the hole 521. Also good.

In such an optical device 5, the evanescent wave of light propagating through the core portion 51 oozes out into the CNT region 14.
Since the optical device 5 uses a photonic crystal optical fiber, light is propagated through the core 51 due to the refractive index difference between the air in the hole 521 and the core 51. Yes. In this embodiment, the CNT region 14 is provided in the hole 521, but it is difficult to completely fill the CNT in the hole 521, and it is estimated that air remains in the hole 521. Therefore, even if the CNT region 14 is provided in the hole 521, it is possible to propagate light into the core portion 51.

Next, a method for manufacturing the optical device 5 will be described.
When providing the CNT region 14 in the hole 521, first, an optical fiber having a cladding part 52 in which the hole 521 is formed and a core part 51 is prepared.
Next, a dispersion liquid in which carbon nanotubes are dispersed is prepared by the same method as in the first embodiment.
Then, this dispersion is poured into the holes 521. As a method for filling the hole 521 with the dispersion liquid, for example, capillary action may be used, or the dispersion liquid may be pushed into the hole 521 by a syringe. Furthermore, suction means such as a pump may be installed on one end side of the hole 521, and the negative liquid may be placed on one end side to fill the hole 521 with the dispersion.
Then, if necessary, the solvent in the dispersion is skipped. As a result, the CNT region 14 is provided in the hole 521.
When the CNT region 14 is provided over the entire length in the hole 521, the optical fiber provided with the CNT region 14 is cut as necessary, and the length dimension of the CNT region 14 (evanescent wave, carbon nanotube, The interaction length). And it has the CNT area | region 14 of a desired length dimension (interaction length with an evanescent wave and a carbon nanotube) by connecting with another optical fiber (normal optical fiber in which the CNT area | region 14 is not provided). An optical device can be obtained.
That is, this optical device is disposed along the first core portion constituting the waveguide, the first cladding portion provided on the outer periphery of the core portion, and the optical axis of the first core portion. And a first optical fiber having a carbon nanotube-containing region provided in the vicinity of the core part, a second core part constituting the waveguide, and an outer periphery of the second core part. An optical device having a second cladding portion and a second optical fiber not provided with a region containing carbon nanotubes, wherein the first optical fiber and the second optical fiber are connected to each other. Become.

  In addition to the same effects as the optical device 4 of the fourth embodiment, the optical device 5 of the present embodiment has the following effects.

The optical device 5 of the present embodiment can be manufactured by providing the CNT region 14 in the air hole (hole 521) of a conventional photonic crystal optical fiber.
Further, in the optical device 5 of the present embodiment, the amount of the evanescent wave that has propagated through the core portion 51 oozes into the CNT region 14 by appropriately adjusting the distance between the hole 521 and the core portion 51. Can be adjusted.

(Sixth embodiment)
A sixth embodiment of the present invention will be described with reference to FIG.
The optical device 6 of the present embodiment is an optical fiber, and includes a core portion 61 and a clad portion 62 that is provided on the outer peripheral side of the core portion 61 and covers the outer periphery of the core portion 61.
The core part 61 extends in a long shape and becomes a waveguide. A hole 611 extending along the optical axis of the core portion 61 is formed at the center of the core portion 61.
The inside of the hole 611 is filled with carbon nanotubes, and a CNT region 14 is provided.
Although the hole 611 is provided along the entire length of the core portion 61, the CNT region 14 may be provided only in a part of the hole 611, and is provided so as to completely fill the hole 611. Also good.
When the CNT region 14 is provided in the hole 611, an optical fiber having a core part 61 in which the hole 611 is formed and a clad part 62 is prepared.
And the dispersion liquid in which the carbon nanotube was disperse | distributed by the method similar to 1st embodiment is adjusted. This dispersion is poured into the holes 611. The method for filling the holes 611 with the dispersion is the same as in the fifth embodiment.
Then, if necessary, the solvent in the dispersion is skipped. Thereby, the CNT region 14 is provided in the hole 611.
As in the fifth embodiment, when the CNT region 14 is provided over the entire length in the hole 611, the optical fiber provided with the CNT region 14 is cut as necessary, and the length dimension of the CNT region 14 ( The interaction length between the evanescent wave and the carbon nanotube is adjusted. And it connects with other optical fiber (The normal optical fiber (The optical fiber which has the core part which comprises a waveguide, and the 2nd clad part which covers the outer periphery of a core part) in which the CNT area | region 14 is not provided). Thus, an optical device having the CNT region 14 having a desired length (interaction length between the evanescent wave and the carbon nanotube) can be configured.
In such an optical device 6, the evanescent wave of light propagating in the core portion 61 oozes out into the CNT region 14.

The optical device 6 of the present embodiment has the following effects in addition to the same effects as the optical device 4 of the fourth embodiment.
The CNT region 14 is provided in the hole 611 formed in the core portion 61, and the outer peripheral surface of the CNT region 14 is in direct contact with the core portion 61. Accordingly, the evanescent wave surely oozes out from the inner peripheral surface of the hole 611 of the core portion 61 into the CNT region 14.

(Seventh embodiment)
A seventh embodiment of the present invention will be described with reference to FIG.
FIG. 10 is a cross-sectional view in the longitudinal direction of the optical device 7 of the present embodiment.
The optical device 7 according to the present embodiment is an optical fiber, and includes a core portion 71 that constitutes a waveguide, and a clad portion 72 that is provided on the outer periphery of the core portion 71 and covers the outer periphery of the core portion 71.
The core portion 71 has a tapered portion 711 and large diameter portions 712 connected to both end portions of the tapered portion 711.
The tapered portion 711 gradually decreases in diameter along the optical axis of the optical fiber and then increases in diameter.
In the large diameter portion 712, there is no variation in the diameter.
The clad part 72 extends along the core part 71. Similar to the core portion 71, the cladding portion 72 also has a tapered portion 721 and large-diameter portions 722 connected to both ends of the tapered portion 721.
The diameter of the tapered portion 721 is gradually reduced along the optical axis of the core portion 71 and then increased. In the portion where the diameter of the taper portion 721 is the smallest, the diameter is about several μm.
In the large diameter portion 722, there is no variation in diameter.
The CNT region 14 extends along the optical axis of the core portion 71 and is provided so as to cover the outer peripheral surface of the tapered portion 721 including the outer peripheral surface of the portion having the smallest diameter of the tapered portion 721.
In such an optical device 7, light propagates through the large-diameter portion 712 of the core portion 71, but when propagating through the portion having the smallest diameter of the tapered portion 711 of the core portion 71 and the vicinity thereof, the tapered portion. It will propagate through the taper part 721 of the clad part 72 through 711.
The evanescent wave of light propagating through the tapered portion 711 in the core portion 71 and the tapered portion 721 in the cladding portion 72 oozes out into the CNT region 14.

    The optical device 7 of this embodiment has the following effects in addition to the same effects as the optical device 4 of the fourth embodiment.

  In this embodiment, the CNT region 14 can be provided only by applying the dispersion containing the CNT used in the first embodiment to the outer peripheral surface of the tapered portion 721. Therefore, it takes time to manufacture the optical device 7. I don't need it.

(Eighth embodiment)
The eighth embodiment of the present invention will be described with reference to FIG.
FIG. 11 shows an optical integrated circuit element 8 as an optical device.
The optical integrated circuit element 8 includes a substrate 11 similar to that of the first embodiment, a cladding layer 12 provided on the substrate 11, and a core layer 13 provided on the cladding layer 12.
In the core layer 13, a plurality of waveguides 831 (831 </ b> A to 831 </ b> D) and 833 are formed.
Among the plurality of waveguides, the optical switch waveguide 831 includes a first waveguide 831A, a second waveguide 831B, an incident-side waveguide 831C, and an emission-side waveguide 831D.
The light incident side end of the first waveguide 831A and the light incident side end of the second waveguide 831B are connected. Further, the light emission side end of the first waveguide 831A and the light emission side end of the second waveguide 831B are connected. That is, it can be said that the second waveguide 831B is arranged in a positional relationship where an optical intersection occurs with respect to the light incident side end and the light emission side end of the first waveguide 831A.
It should be noted that portions other than the light incident side end and the light emission side end of the second waveguide 831B are not optically coupled to the first waveguide 831A (so that no optical intersection occurs). , Spaced apart.

Further, the incident-side waveguide 831C is connected to the intersection of the light incident side end of the first waveguide 831A and the light emission side end of the second waveguide 831B.
Further, the emission-side waveguide 831D is connected to the intersection of the light emission side end of the first waveguide 831A and the light emission side end of the second waveguide 831B.
The CNT region 14 is provided directly on the first waveguide 831A along the optical axis of the first waveguide 831A. Note that the CNT region is not provided on the second waveguide 831B.
Here, the first waveguide 831A, the second waveguide 831B, the incident-side waveguide 831C, the emission-side waveguide 831D formed in the substrate 11, the clad layer 12, and the core layer 13 are provided. An optical switch is configured by the CNT region 14 provided on the waveguide 831A.
In this optical switch, light from the incident-side waveguide 831C is branched into a first waveguide 831A and a second waveguide 831B.
The CNT region 14 is provided on the first waveguide 831A, and the absorptance of light passing through the first waveguide 831A changes according to the intensity of light passing through the first waveguide 831A. When a change occurs in the light absorption rate, the phase of the light passing through the first waveguide 831A also changes.

For example, when the intensity of light incident on the first waveguide 831A is weak, a large phase change, for example, the phase changes by 180 °. In this case, the phase of the light emitted from the first waveguide 831A and the phase of the light emitted from the second waveguide 831B are shifted by 180 °. Light is prevented from propagating through the waveguide 831D.
On the other hand, when the intensity of the light incident on the first waveguide 831A is strong, for example, a large phase change does not occur in the light in the first waveguide 831A, and the light is emitted from the first waveguide 831A. And the light emitted from the second waveguide 831B do not cancel each other. Therefore, the light emitted from the first waveguide 831A and the light emitted from the second waveguide 831B are combined, and the light propagates through the emission-side waveguide 831D.
In addition, the length dimension along the optical axis of the 1st waveguide 831A of the CNT area | region 14 is about 100 micrometers-10 mm, for example.

In addition to the optical switch waveguide, another waveguide 833 is formed in the core layer 13. On the other waveguide 833, the CNT region 14 is provided as in the first embodiment.
An optical device similar to that of the first embodiment, including the substrate 11, the clad layer 12, the other waveguide 833 formed in the core layer 13, and the CNT region 14 formed on the other waveguide 833. Will be constructed.

Such an optical integrated circuit element 8 can be manufactured by the same method as in the first embodiment.
That is, after the clad layer 12 and the core layer 13 are provided on the substrate 11 by the same method as in the first embodiment, the core layer 13 is irradiated with ultraviolet rays according to the patterns of the waveguides 831 and 833.

Next, the function and effect of the optical integrated circuit element 8 of this embodiment will be described. In addition to the same effects as those of the optical device 1 of the first embodiment, the optical integrated circuit element 8 has the following effects.
In this optical integrated circuit element 8, the substrate 11, the clad layer 12, and the core layer 13 that constitute the optical switch, and the substrate 11, the clad layer 12, and the core layer 13 that constitute the optical device similar to the first embodiment are shared. Therefore, integration of the optical device can be achieved.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the first to third embodiments, when the CNT region 14 is provided, a dispersion containing carbon nanotubes is applied on the waveguide. A method for forming the CNT region 14 is as follows. Not limited. For example, a catalyst such as Ni or Co may be provided on the waveguide, and the CNT region 14 may be formed by a CVD method. Specifically, a gaseous carbon-containing material is pyrolyzed, carbon nanotubes are generated from the generated carbon, and a CNT region is formed.
In the first to third embodiments, the CNT region 14 is provided so as to cover at least the upper surface of the waveguide. However, the present invention is not limited thereto, and the CNT region is provided so as to cover only the side surface of the waveguide. Also good.

Furthermore, for example, as shown in FIG. 12, when adopting a configuration in which the waveguide 15 on the substrate 11 is covered with the cladding layer 16, the carbon nanotubes may be dispersed in the cladding layer 16. In this case, the entire cladding layer 16 is disposed along the optical axis of the waveguide 15 and becomes a region containing carbon nanotubes provided in the vicinity of the waveguide 15.
For example, after the waveguide 15 is formed by etching, the side surfaces and the upper surface of the waveguide 15 are covered with the cladding layer 16. At this time, the cladding layer 16 is made of resin, and the carbon nanotubes are dispersed in the resin. The clad layer 16 is made of a so-called polymer nanocomposite containing carbon nanotubes.
Alternatively, the cladding layer 16 may be produced by a sol-gel method, and the carbon nanotubes may be dispersed in the cladding layer 16. Carbon nanotubes are dispersed in the sol of the cladding layer 16 and applied to the substrate 11 and the waveguide 15.
In such a configuration, the carbon nanotubes are dispersed throughout the cladding layer 16, but since the evanescent wave reaches only the vicinity of the waveguide 15, the carbon nanotubes existing in the vicinity of the waveguide 15 and Interaction with evanescent waves.

In the first to third embodiments, the clad layer 12 and the like are laminated on the substrate 11 and the waveguides 131, 23, and 332 are formed, and then the CNT region 14 is provided to provide the optical devices 1 to 3. However, the present invention is not limited to this. For example, an optical device may be manufactured by providing the CNT region 14 in a commercially available structure in which the waveguides 131, 23, and 332 are provided in advance. In this way, an optical device can be easily manufactured.
Furthermore, as described in the first to third embodiments, the CNT region 14 may be provided over the entire length of the waveguides 131, 23, 332, and a part of the waveguides 131, 23, 332 may be provided. You may provide so that it may cover. For example, a plurality of CNT regions 14 can be provided on the waveguides 131, 23, 332 at predetermined intervals.
As described above, when the CNT region 14 is provided in a part of the waveguides 131, 23, 332, the waveguides 131, 23, 332 are covered with a mask in which openings having a predetermined pattern are formed. A CNT dispersion may be applied from above. Thereby, the CNT region 14 can be provided at the position of the opening of the mask.

Furthermore, in the first embodiment to the third embodiment, the clad 12 layer is laminated on the substrate 11, and the waveguides 131, 23, and 332 are formed on the clad layer 12. For example, a waveguide may be formed by focusing and irradiating femtosecond pulses on glass or bulk glass deposited on a substrate.
That is, an optical device is provided that includes a substrate, a waveguide provided on the substrate, and a region containing a carbon nanotube provided in the vicinity of the waveguide and disposed along the optical axis of the waveguide. The Rukoto.
Also in this case, by collecting and irradiating femtosecond pulses, a plurality of waveguides can be formed on the substrate, and integration of optical devices can be achieved.

In the second embodiment, the cladding layer 12 is a layer made of SiO ₂ , and the waveguide 23 is a layer in which Ge is added to a layer containing SiO _2. It is also possible to use a resin layer.
For example, an ultraviolet curable resin composition layer is formed on the cladding layer. And after irradiating an ultraviolet-ray through the photomask of a predetermined pattern with respect to the ultraviolet curable resin composition layer surface and exposing, the ultraviolet curable resin composition layer is heated. A waveguide is formed by dissolving and removing an unexposed portion of the ultraviolet curable resin composition layer after heating using a developer.

Furthermore, in the present invention, an optical device (optical switch) 9 as shown in FIG. 13 can be provided.
The optical device 9 includes a substrate 11, a clad layer 12, and a core layer 13 similar to those in the first embodiment. In the core layer 13, a pair of waveguides 931 and 933 (a first waveguide 931 and a second waveguide 933) are formed. The pair of waveguides 931 and 933 are arranged in a substantially X shape in a plane, and the central portions in the longitudinal direction of the pair of waveguides 931 and 933 optically intersect with each other. A CNT region 14 is provided on the upper surface of the intersecting portion. The CNT region 14 is provided across the pair of waveguides 931 and 933 and is disposed along the optical axis of the waveguides 931 and 933.
In such an optical device 9, when the intensity of light incident on the pair of waveguides 931 and 933 is weak, the light absorption rate by the CNT region 14 becomes large, so that a large phase change occurs for each light. Occurs. The light whose phase has been changed is optically coupled while passing through the pair of waveguides 931 and 933, and is emitted from the respective waveguides 931 and 933.
In addition, when the intensity of the light incident on the pair of waveguides 931 and 933 is large, it is considered that the light is hardly absorbed by the CNT region 14, so that a large phase with respect to the light incident on the waveguides 931 and 933 No change occurs. While passing through the pair of waveguides 931 and 933, each light is optically coupled and emitted from the waveguides 931 and 933, but the phase of the emitted light from the waveguides 931 and 933 guides weak light. This is different from the case where the light enters the waveguides 931 and 933.

  In FIG. 13, the CNT region 14 is formed on the upper surface of the optically intersecting portions of the waveguides 931 and 933. However, the present invention is not limited to this. Also good.

Furthermore, in the present invention, an optical device 5 ′ as shown in FIG. 14 can be provided.
This optical device 5 ′ has a core part 51 ′ constituting a waveguide and a clad part 52 ′ provided on the outer periphery of the core part 51 ′.
Core part 51 'is an air hole formed in the center part of clad part 52'. A plurality of holes 521 are formed in the cladding portion 52 ′ so as to surround the core portion 51 ′. The hole 521 extends along the optical axis of the core portion 51 ′ and is disposed substantially parallel to the core portion 51 ′. Of the holes 521, the holes 521 that are located in the vicinity of the core part 51 ′ and that surround the core part 51 ′ are filled with CNTs, and the CNT region 14 is provided.
Also in such an optical device 5 ′, the evanescent wave of light propagating in the core portion 51 ′ oozes out into the CNT region 14.

Next, examples of the present invention will be described.
An optical device 1 similar to that of the first embodiment was produced.
In this example, the optical device 1 was manufactured by the following procedure.
First, the cladding layer 12 and the core layer 13 on which the waveguide 131 is not formed are provided on the substrate 11 (hereinafter referred to as a laminate).
The cladding layer 12 contains SiO ₂ as in the first embodiment, and the core layer 13 is obtained by adding Ge to the SiO ₂ layer.
The clad layer 12 has a thickness of 40 μm, the core layer 13 has a thickness of 6 μm, and the refractive index difference between the clad layer 12 and the core layer 13 is 0.75%.
Thereafter, the laminated body was moved while irradiating the core layer 13 with ultraviolet rays to form the waveguide 131. By irradiating the core layer 13 with ultraviolet rays, the refractive index of the ultraviolet irradiation region increases, and the waveguide 131 is formed.
In this embodiment, in order to increase the sensitivity to ultraviolet rays, the laminate is previously subjected to hydrogen treatment at a high pressure.
In addition, the laminate was annealed after UV irradiation to stabilize the change in refractive index.
Thereafter, a dispersion containing CNTs was sprayed onto the waveguide 131 of the laminate to provide the CNT regions 14.
The total length of the waveguide 131 is 10 mm, and the CNT region 14 is provided over the entire length of the waveguide 131.

FIG. 15 shows the transmission spectrum of the optical device 1. The transmission spectrum S1 in FIG. 15 is a spectrum with a polarization that has the maximum loss, and the transmission spectrum S2 is a spectrum with a polarization that has the minimum loss.
FIG. 16 shows the saturable absorption characteristic in the polarization that causes the maximum loss of the optical device 1.

Next, the optical device 1 was mounted on the mode-locked laser apparatus 100 shown in FIG.
The mode-locked laser device 100 includes a resonator 101 including a gain region and an excitation laser light source 102 for generating an optical gain in the gain region.
The resonator 101 includes an isolator 103, an optical amplifier (gain region) 104 to which pumping light from the pumping laser light source 102 is supplied, a polarization plane controller 105, and an optical fiber 106 that connects these in a ring shape. .
The optical amplifier 104 has a rare earth doped optical fiber. This rare earth-doped optical fiber is an optical fiber in which a rare-earth (light amplification medium) such as ytterbium (Yb) or erbium (Er) is added to the core portion of a single mode optical fiber. The optical amplification medium is excited by light from the excitation laser light source 102 and amplifies the light.
In this embodiment, for example, an erbium (Er) -doped optical fiber having a large gain in the vicinity of a wavelength of 1550 nm is used.

Light from the pumping laser light source 102 is introduced into the optical amplifier 104 and is introduced into the polarization plane controller 105 through the optical fiber 106 and the isolator 103. Light from the polarization plane controller 105 is introduced into the waveguide 131 of the optical device 1 through the optical fiber 106. A part of the light incident on the optical device 1 passes through the waveguide 131 and is extracted from the 3 dB coupler 108 to the outside of the resonator 101. The light extracted from the coupler 108 is output via the second optical amplifier 109.
On the other hand, another part of the light from the coupler 108 is again introduced into the optical amplifier 104 via the optical fibers 106 and 107 and the isolator 103.
In FIG. 17, reference numeral 107 denotes a single mode fiber (SMF).

Here, at the beginning when the mode-locked laser apparatus 100 is turned on, the intensity of light circulating in the mode-locked laser apparatus 100 is weak, and unstable multimode oscillation is performed.
As the light circulates in the mode-locked laser device 100, the intensity of the light increases. When the power at which the saturable absorption characteristic of the carbon nanotube appears is reached, depending on the recovery time of the saturable absorption characteristic of the carbon nanotube, a mode-locked state is reached and a stable pulse oscillation state is reached.

FIG. 18 shows a spectrum of light output from the mode-locked laser apparatus 100. The width of the 3 dB spectrum is 1.7 nm or less.
FIG. 19 shows an autocorrelation waveform measured by SHG (Second Harmonic Generation). The full width at half maximum was 2.12 ps.
Further, FIG. 20 shows an output waveform. It can be seen from FIG. 20 that the repetition frequency is 1.55 MHz.

Thus, in the mode-locked laser apparatus 100 using the optical device 1, it was found that pulse oscillation can be obtained, and a mode-locked laser apparatus that exhibits sufficient characteristics can be obtained.
Note that the mode-locked laser apparatus 100 of the present embodiment exhibits the same characteristics as a mode-locked laser apparatus using a device in which a CNT region is formed on a conventional glass substrate instead of the optical device 1.

This is due to the following reason.
In the optical device 1 of the present embodiment, the interaction length between the carbon nanotube and the evanescent wave is 10 mm. This interaction length includes the amount of evanescent wave oozing from the waveguide 131, the thickness of the CNT region 14, and the thickness of the CNT region in the conventional optical device in which the CNT region is formed on the glass substrate (Patent Document 1). Is determined in consideration of That is, the optical device 1 is an optical device that exhibits saturable absorption characteristics equivalent to that of an optical device in which a CNT region is formed on a glass substrate.
Therefore, it can be seen that if the interaction length between the carbon nanotube and the evanescent wave in the optical device 1 is further increased, it is possible to provide an optical device having performance equal to or higher than that of the conventional optical device. The example results suggest this.

1 is a perspective view showing an optical device according to a first embodiment of the present invention. It is sectional drawing of the optical device concerning 1st embodiment. It is a figure which shows the manufacturing process of an optical device. It is sectional drawing of the optical device concerning 2nd embodiment of this invention. It is sectional drawing of the optical device concerning 3rd embodiment of this invention. It is a perspective view of the optical device concerning 4th embodiment of this invention. It is sectional drawing of the optical device concerning 4th embodiment. It is sectional drawing of the optical device concerning 5th embodiment of this invention. It is sectional drawing of the optical device concerning 6th embodiment of this invention. It is sectional drawing of the optical device concerning 7th embodiment of this invention. It is sectional drawing of the optical device concerning 8th embodiment of this invention. It is sectional drawing of the optical device concerning the modification of this invention. It is a perspective view of the optical device concerning the modification of this invention. It is sectional drawing of the optical device concerning the modification of this invention. It is a figure which shows the transmission spectrum of the optical device in an Example. It is a figure which shows the saturable absorption characteristic of the optical device in an Example. It is a schematic diagram which shows the structure of the mode synchronous laser apparatus in an Example. It is a figure which shows the spectrum of the light output from the mode synchronous laser apparatus of an Example. The SHG autocorrelation waveform of the mode synchronous laser apparatus of an Example is shown. The output waveform of the mode synchronous laser apparatus of an Example is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical device 2 Optical device 3 Optical device 4 Optical device 5 Optical device 5 'Optical device 6 Optical device 7 Optical device 8 Optical integrated circuit element (optical device)
9 Optical device 11 Substrate 12 Clad layer 13 Core layer 14 CNT region (region containing carbon nanotubes)
DESCRIPTION OF SYMBOLS 15 Waveguide 16 Clad layer 23 Waveguide 33 Core layer 41 Core part 42 Clad part 51 Core part 51 'Core part 52 Clad part 52' Clad part 61 Core part 62 Clad part 71 Core part 72 Clad part 100 Mode synchronous laser apparatus 101 Resonator 102 Excitation laser light source 103 Isolator 104 Optical amplifier 105 Polarization plane controller 106 Optical fiber 107 Optical fiber 108 Coupler 109 Optical amplifier 131 Waveguide 132 Other portion 331 Base 332 Waveguide 421 Plane portion (notch portion)
521 Hole 611 Hole 711 Tapered portion 712 Large diameter portion 721 Tapered portion 722 Large diameter portion 831C Incident side waveguide 831D Output side waveguide 831 Waveguide 831A First waveguide 831B Second waveguide 833 Waveguide 931 First Waveguide 933 Second waveguide L1 Distance L2 Distance S1 Transmission spectrum S2 Transmission spectrum

Claims (9)

A waveguide;
A region containing carbon nanotubes disposed along the optical axis of the waveguide and provided in the vicinity of the waveguide;
An optical device comprising: The optical device according to claim 1.
A substrate,
A clad layer formed on the substrate,
The waveguide provided on the cladding layer and having a higher refractive index than the cladding layer;
A region containing carbon nanotubes disposed along the optical axis of the waveguide and provided in the vicinity of the waveguide;
An optical device comprising: The optical device according to claim 1.
Comprising an optical fiber,
The optical fiber includes a core part constituting the waveguide;
A clad portion provided on the outer peripheral side of the core portion;
A region containing carbon nanotubes disposed along the optical axis of the core portion and provided in the vicinity of the core portion;
An optical device comprising: The optical device according to claim 3.
The clad part is formed with a notch cut out along the optical axis of the core part,
This notch is located in the vicinity of the core,
An optical device characterized in that a region containing the carbon nanotube is provided on the notch. The optical device according to claim 3.
In the vicinity of the core portion of the cladding portion, a hole extending along the optical axis of the core portion is formed,
An optical device characterized in that a region containing the carbon nanotube is provided inside the hole. The optical device according to claim 3.
A hole extending along the optical axis of the core portion is formed in the center portion of the core portion,
An optical device characterized in that a region containing the carbon nanotube is provided inside the hole. The optical device according to claim 3.
The clad part has a taper part that expands after its diameter gradually decreases along the optical axis of the core part,
The region containing the carbon nanotube is provided so as to cover at least the outer peripheral surface of the portion having the smallest diameter of the tapered portion. The optical device according to any one of claims 1 to 7,
The optical device is an optical switch,
An optical device comprising: a second waveguide disposed in a positional relationship where an optical intersection occurs with respect to a part of the waveguide. The optical device according to claim 8.
The end of the second waveguide on the light output side is connected to the end of the waveguide on the light output side, and the end of the second waveguide on the light incident side is connected to the end of the waveguide. Connected to the end of the light incident side,
An incident-side waveguide for entering light into the second waveguide and the waveguide;
An exit-side waveguide that emits light from the second waveguide and the waveguide; and
An optical device is provided.

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