JP2005043760A - Optical circuit and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical circuit of which loss is low and in which optical design is easily reflected. <P>SOLUTION: The optical circuit is configured so that a dielectric multilayered film wavelength filter 2 is fixed in the groove provided in the substrate 4 of an optical waveguide with a photosetting resin material and also a photosetting resin material region 13 where the photosetting resin material is filled is formed on the substrate and, on the other hand, lens-shaped media 5-a, 5-b are self-formed by irradiating the photosetting resin material of the photosetting resin material region 13 with formation light having a wavelength which gives the change of a refractive index. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical circuit using a self-forming lenticular medium or a self-forming optical waveguide in a groove in an optical waveguide, and a method for manufacturing the same.

  The advent of web browsers as killer applications brought about the rapid spread of the Internet, increased communication traffic, and further explosive progress was expected. As a result, the development of components for wavelength division multiplexing optical communication systems is overestimated in the long-haul market around North America around 2000 AD, and expectations for dotcom companies and the expansion of optical component production are overheating. As a result, a light bubble was generated. The soaring forecast based on optimism has collapsed, and the excessively invested optical component market has begun to expand into the undeveloped area of metro access optical communications to seek whereabouts. However, everyone has to be skeptical about the current situation in which the cost reduction of parts due to the same mass production effect can not be expected and the active development of high-end technology that requires excessive investment. In the future development trend of optical components for communication, it will be essential not only to adjust the market such as multi-sourced procurement parts, but also to upgrade the cheaper developed products by using cheaper component integration technology.

  FIG. 13 shows a wavelength division multiplexing optical circuit formed by inserting a dielectric multilayer wavelength filter into a groove provided in a conventional optical waveguide circuit substrate, and FIG. 14 shows a detailed view of the filter insertion part. In both figures, 1 is an optical waveguide, 1-a is an input optical port, 1-b1 is a filter transmitted light output port, 1-b2 is a filter reflected light output port, 2 is a dielectric multilayer wavelength filter, and 3 is photocuring. Filter insertion grooves filled with a conductive resin material, 4 is an optical waveguide substrate, and 4-1 and 4-2 are an input / reflection light port side and a transmission light port side of the optical waveguide substrate 4.

  FIG. 15 shows the result of analyzing the state of signal light propagation after insertion and fixing of the dielectric multilayer wavelength filter 2 in the groove, that is, from the input optical port 1-a into the photocurable resin material after solidification. Indicated. This corresponds to the signal light propagation analysis result in the filter groove 3 according to the prior art. Here, FIG. 15A shows the refractive index distribution of the photocurable resin material, FIG. 15B shows the signal light (1550 nm) propagation analysis result, and FIG. 15C shows the signal light (1550 nm) propagation analysis phase distribution result. Each is shown. 15A shows a case where the refractive index difference Δn is 0.000, and reference numerals 151, 152, 153, and 154 in FIG. 15B indicate the relative light intensity contours of 0.1,. Each case of 2, 0.3, and 0.4 is shown.

  The wavelength division multiplexing optical circuit using the wavelength filter insertion type shown in FIG. 13 has a conventional optical circuit configuration that has been proposed in many subscriber optical multiplexing / demultiplexing circuit components (for example, Japanese Patent Laid-Open No. 57-68098). . Since the optical circuit has an optical thin film and an optical circuit board separated from each other, there is a possibility of pursuing low-cost and high-quality parts procurement for each part, and easy positioning of the optical filter part in the groove. From the two points of low-cost assembly technology that can be achieved by passive alignment that can be performed, it is considered to be an optical component integration technology advantageous for cost reduction, and various configurations have been studied.

  The wavelength division multiplexing operation in such a wavelength division multiplexing optical circuit will be described. According to the wavelength division multiplexing optical circuit of the prior art, the multiplexed signal light having the wavelengths λ1 and λ2 propagating through the optical waveguide 1 of the input optical port 1-a shown in FIGS. It will radiate | emit to the filter insertion groove | channel 3 formed in this. The emitted light is dissipated in the filter insertion groove 3, but the wavelength λ2 of the signal light in the transmission band of the dielectric multilayer wavelength filter 2 is transmitted through the dielectric multilayer wavelength filter 2 and is disposed opposite to the filter. Optical coupling is realized at the transmitted light output port 1-b1. On the other hand, the wavelength λ1 of the signal light outside the transmission band is reflected by the surface of the dielectric multilayer film wavelength filter 2 and then propagates in the filter insertion groove 3 to the reflected light output port 1-b2 for the reflected light port. It is configured to be optically coupled. By adopting this configuration, the wavelength multiplexed signal light can be divided into the wavelength λ1 and the wavelength λ2.

  FIG. 15 shows a state of propagation of signal light emitted from the optical waveguide 1 to the filter insertion groove 3. Here, the coordinate axes shown in FIG. 14 coincide with the coordinate axes in FIG. That is, the x-axis indicates the direction perpendicular to the waveguide propagation direction at the end face of the optical waveguide 1, and the z-axis indicates the longitudinal direction (waveguide propagation direction) of the filter insertion groove 3.

  Next, the analysis results will be described sequentially. (A) in FIG. 15 shows the contour distribution of the refractive index distribution in the photocurable resin material filling region (see FIG. 14). In the figure, a uniform refractive index distribution is shown because there is no contour distribution. This corresponds to the refractive index distribution configuration inside the filter insertion groove 3 formed by the prior art. From the waveguide 1 having the input optical port 1-a (in the figure, the waveguide 1 is analyzed assuming that it is a straight waveguide), the filter insertion groove 3 having such a uniform refractive index distribution is used. The signal light propagation to was analyzed. The propagation analysis light intensity distribution at this time is shown in FIG. 15B, and the phase distribution is shown in FIG. 15C. As shown in FIG. 15B, it is observed that the light emitted from the optical waveguide spreads immediately. Further, in FIG. 15C, if the state of propagation of the equiphase surface is observed (the color tone line portion in the same stage in the figure), the narrow line and the wavefront curvature are observed in the propagation axis direction (z axis) of the flat line distribution at the center. In the phase distribution, it can be confirmed that the guided light is spread into the filter insertion groove 3 sharply and spatially. In addition, the following publications exist as patent documents disclosing this kind of known technology.

JP-A-57-68098

  In the wavelength division multiplexing optical circuit of the dielectric multilayer wavelength filter insertion type according to the prior art as described above, since the radiation of incident signal light to the dielectric multilayer wavelength filter 2 in the filter insertion groove 3 is significant, it is planar. Signal light having wave vector vectors directed in various directions is incident on the dielectric multilayer wavelength filter 2 laminated on the substrate, and the demultiplexing of the dielectric multilayer wavelength filter 2 laminated in a plane is performed. The characteristics (center wavelength, transmission bandwidth) are deteriorated, and the characteristics as originally designed for the dielectric multilayer wavelength filter 2 cannot be obtained (Massunori Ito, Fumio Koyama “Spot size dependence of dielectric multilayer filters” “See 2002 IEICE Electronics Society Conference c-3-90.) In addition, in both cases of the reflected wave and the transmitted wave in the dielectric multilayer film wavelength filter 2, it is difficult to suppress the spread of each beam propagation, so that the deterioration of the filter characteristics is determined by the incident beam characteristics. In addition to the factors, the degradation of the coupling efficiency between the optical waveguide 1 of the filter reflected light output port 1-b2 or the filter transmitted light output port 1-b1 and the light reflected or transmitted by the dielectric multilayer wavelength filter 2 is added. . Thus, the insertion loss of the dielectric multilayer wavelength filter 2 according to the configuration of the related art is increased.

  The present invention has been made in view of the above prior art, and an object of the present invention is to provide an optical circuit having a lower loss and easily reflecting an optical design, and a method for producing the optical circuit.

  The configuration of the present invention that achieves the above object is characterized by the following points.

1) an optical thin film that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed by a photocurable resin material that fills the grooves;
The core portion end of the optical waveguide facing the inner surface of the groove by propagating and radiating forming light having a wavelength that gives a refractive index change to the photocurable resin material to the photocurable resin material through the optical waveguide Or a lens structure formed in the vicinity of the surface of the optical thin film installed in the groove.

2) a dielectric multilayer wavelength filter that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed by a photocurable resin material that fills the grooves;
The core portion end of the optical waveguide facing the inner surface of the groove by propagating and radiating forming light having a wavelength that gives a refractive index change to the photocurable resin material to the photocurable resin material through the optical waveguide Or a lens structure formed in the vicinity of the surface of the dielectric multilayer film wavelength filter installed in the groove.

3) an optical thin film that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed with a photocurable resin material that fills the grooves;
The optical waveguide facing the inner surface of the groove by propagating and radiating forming light having a wavelength that gives a refractive index change to the photocurable resin material to the photocurable resin material at least twice through the optical waveguide. And an optical waveguide core structure formed from the core part to the optical thin film or the vicinity thereof.

4) A dielectric multilayer wavelength filter that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed by a photocurable resin material that fills the grooves;
The core portion of the optical waveguide facing the inner surface of the groove by propagating and irradiating the photocurable resin material with a wavelength that gives a refractive index change to the photocurable resin material through the optical waveguide And an optical waveguide core structure formed up to the dielectric multilayer film wavelength filter or the vicinity thereof.

5) In the optical circuit described in 1) or 3) above,
The groove shape of the filling region filled with the photocurable resin material has a rhombus structure, and the optical thin film is inserted and fixed at the diagonal position.

6) In the optical circuit described in the state 2) or 4),
The groove shape of the filling region filled with the photocurable resin material has a rhombus structure, and a dielectric multilayer film wavelength filter is inserted and fixed at the diagonal position.

7) In a method for manufacturing an optical circuit in which an optical thin film is inserted into one or more grooves provided in an optical waveguide substrate,
The optical thin film is positioned and fixed in the groove, and the forming light having a wavelength that changes the refractive index of the photocurable resin material is formed from the optical waveguide in the groove filled with the photocurable resin material. Propagating and radiating into the groove once to form a lens structure in the vicinity of the core portion end of the optical waveguide facing the inner surface of the groove or the surface of the optical thin film installed in the groove,
Thereafter, the light-curing resin material in a portion excluding the lens structure forming portion is subjected to light irradiation with an intensity capable of polymerization, irradiation with other wavelength light, or a heat treatment step on the entire light-curing resin material, The photocurable resin material is solidified as a whole, and the optical thin film inserted into the groove and the optical waveguide are optically positioned and fixed.

8) In a method for manufacturing an optical circuit in which a dielectric multilayer wavelength filter is inserted into one or more grooves provided in an optical waveguide substrate,
Positioning and fixing the dielectric multilayer film wavelength filter in the groove, and forming light having a wavelength that gives a refractive index change to the photocurable resin material in the groove filled with the photocurable resin material. In the vicinity of the end of the core portion of the optical waveguide facing the inner surface of the groove or the surface of the dielectric multilayer wavelength filter installed in the groove by being propagated and emitted once into the groove from the optical waveguide Forming the lens structure,
Thereafter, the light-curing resin material in a portion excluding the lens structure forming portion is subjected to light irradiation with an intensity capable of polymerization, irradiation with other wavelength light, or a heat treatment step on the entire light-curing resin material, The photocurable resin material is solidified as a whole, and the dielectric multilayer wavelength filter inserted in the groove and the optical waveguide are optically positioned and fixed.

9) In a method of manufacturing an optical circuit in which an optical thin film is inserted into one or more grooves provided in an optical waveguide substrate,
The optical thin film is positioned and fixed in the groove, and the forming light having a wavelength that changes the refractive index of the photocurable resin material is formed from the optical waveguide in the groove filled with the photocurable resin material. By propagating and radiating twice or more into the groove, an optical waveguide core structure is formed from the core portion end of the optical waveguide facing the inner surface of the groove to the optical thin film or the vicinity thereof,
Thereafter, the entire photocurable resin material is subjected to light irradiation with a strength capable of polymerizing the portion of the photocurable resin material excluding the optical waveguide core structure forming portion, irradiation with other wavelength light, or a heat treatment step. The photocurable resin material is solidified as a whole, and the optical thin film inserted into the groove and the optical waveguide are optically positioned and fixed.

10) In a method for manufacturing an optical circuit in which a dielectric multilayer wavelength filter is inserted into one or more grooves provided in an optical waveguide substrate,
Positioning and fixing the dielectric multilayer film wavelength filter in the groove, and forming light having a wavelength that gives a refractive index change to the photocurable resin material in the groove filled with the photocurable resin material. Optical waveguide core structure from the optical waveguide core end facing the inner surface of the groove to the dielectric multilayer wavelength filter or the vicinity thereof by propagating and radiating into the groove from the optical waveguide twice or more Form the
Thereafter, the entire photocurable resin material is subjected to light irradiation with a strength capable of polymerizing the portion of the photocurable resin material excluding the optical waveguide core structure forming portion, irradiation with other wavelength light, or a heat treatment step. The photocurable resin material is solidified as a whole, and the dielectric multilayer wavelength filter inserted in the groove and the optical waveguide are optically positioned and fixed.

11) In the method for manufacturing an optical circuit described in any one of 7) to 10) above,
In order to introduce the formation light into the groove filled with the photocurable resin material, the groove filled with the photocurable resin material and the photocurable resin material connected by the optical waveguide to the groove before filling. A film-type optical waveguide circuit obliquely processed at an angle of approximately 45 degrees or an optical fiber obliquely processed at an angle of approximately 45 degrees is inserted into the groove portion before filling with the photocurable resin material to form light. Introducing and irradiating the groove.

12) In the method for manufacturing an optical circuit described in 1) or 2) above,
In forming the lens structure in the groove filled with the photo-curable resin material, the coherent forming light is introduced using at least two or more ports of the optical waveguide substrate to form the plurality of ports. Forming a lens structure at an arbitrary position in the groove filled with the photo-curing resin material by causing the phases to interfere with each other.

  According to the present invention configured as described above, in an optical circuit realized by inserting an optical thin film component into a groove provided in the optical waveguide circuit, an outgoing beam from the optical waveguide upon optical coupling from the optical waveguide to the optical thin film component This can solve the problem that the characteristics of the optical thin film component cannot be sufficiently reproduced and the function as an optical circuit is deteriorated. That is, by using the in-groove self-forming lens or the self-forming optical waveguide according to the present invention, a beam converged from the optical waveguide can be incident on the optical thin film component, and the reflection from the optical thin film component or the optical thin film can be obtained. Since the signal light transmitted through the components can be optically coupled with the optical waveguide with high efficiency, an optical thin film component insertion type optical circuit with lower loss and easily reflecting the optical design can be realized.

  First, the principle common to the embodiments of the present invention will be described. FIG. 1 shows the irradiation light quantity dependency of the refractive index change of the photo-curing resin material used in common in each embodiment of the present invention.

In producing a self-forming optical waveguide or a self-forming lenticular medium, in order to bring about a resin internal refractive index difference according to the amount of irradiation light,
(1) Process of exposure by changing the wavelength in two stages using a mixed solution of a plurality of resin materials as a photo-curable resin material (Tatsuya Yamashita, Kagami Gaku, Hiroshi Ito “Photo-curing using multi-mode optical fiber” "Self-formation of optical waveguides in conducting resins", IEICE Technical Report, pp.31-36, (1999-10) and Noritoshi Watanabe, Kentaro Miyata, Keiichi Murata, Osamu Mikami, Self-Forming Optical Waveguides Using Green Lasers ”Production Science Report, pp.11-13, (2002-6).),
(2) Using a material obtained by doping a polyimide varnish with a photosensitive group to obtain a refractive index distribution corresponding to the amount of irradiation light by exposure, and then realizing a waveguide structure through a heat treatment process (Kenichi Yamashita, Takashi Hashimoto, Kunishige Oe, Noriyoshi Munekazu, Ryusuke Naito, Shu Mochizuki: "New core-cladding technology for self-formed optical waveguides using photosensitive polyimide" 50th Japan Society of Applied Physics, 27a-W-3).
And (3) A method of realizing a sufficient difference between the light intensity for solidifying the resin constituting the high refractive index portion and the light intensity for solidifying the resin constituting the low refractive index portion (Naohiro Hirose “Optical Waveguide”) (See Japanese Patent Application Laid-Open No. 2002-258095.)
These three steps are representative steps.

In any process, it is necessary to go through another process in addition to the irradiation process. FIG. 1 shows the irradiation light amount dependency of the refractive index difference of the photocurable resin material in the first process of initially providing the refractive index difference distribution in the photocurable resin material in the groove. As shown in the figure, the refractive index change due to the reaction light dose dependence of the photo-curing resin material shows almost no change in the refractive index below a certain critical dose. As a result, the refractive index increases. On the other hand, when the dose exceeds a certain level, the refractive index is saturated and it is difficult to change the refractive index. Regarding the change in the refractive index with respect to the irradiation dose, reports by Maruyama et al. (Hideki Maruyama, Teruki Mitsuyama, Yasuhiro Kiyomura, Masamitsu Haruna “Resin Curing with Simultaneous Measurement of Refractive Index and Thickness Using Low Coherence Interference The actual measurement results are reported in "Application to sex assessment", IEICE Transactions C, vol. J85-C, no.2, pp.103-106, February 2002). It can be confirmed that this report shows the same tendency as the refractive index change curve in the principle explanatory diagram according to the present invention. FIG. 1 used for explaining the principle can be considered to show a typical tendency of the refractive index dependency with respect to the light irradiation amount of the photocurable resin material.

  Fill the groove with a photo-curable resin material showing the dependency of the refractive index on the irradiation amount as described above, and model the configuration in which the formation light (light having a wavelength of 600 nm or less) is irradiated with an appropriate amount of light through the linear optical waveguide, The result of the analysis by computer simulation is shown in FIG. Based on the premise of the analysis, the relationship between the irradiation amount of the formed light and the refractive index change amount of the photo-curing resin material is the relational expression (1) proposed by Anthony S. Kewitsch et al. (Anthony S. Kewitsch and Amnon Yariv, “Self-focusing and self-trapping of optical beams upon photopolymerization, "Optics Letters, vol. 21, no. 1, pp. 24-26 (1996)). In FIG. 2, 13 is a photocurable resin material filling region, 1-a is an input light port, 4-1 is an input / reflection light port side of the optical waveguide substrate 4, and 5 is a photocurable resin material filling region 13. Lenticular medium. In FIG. 6, (a) shows the analysis coordinates, (b) shows the contour distribution of the refractive index distribution of the lenticular medium formed by one-shot irradiation as an analysis result, and (c) shows the lenticular medium formed. The signal light propagation characteristics in the refractive index distribution are shown.

Further, as shown in (a) in the figure, the formation light (ultraviolet light having a wavelength of 600 nm or less) is excited from the input light port 1-a, and emitted to the photocurable resin material filling region 13 which is a groove through a straight waveguide.・ Irradiate. Irradiation is performed once at an irradiation amount of 20.0 × 10 ⁻⁶ mJ. An analysis result of the refractive index distribution obtained in this irradiation process is shown in FIG. As shown in the figure, the refractive index distribution has a lens-like bulge. It was also confirmed that when the irradiation was performed a plurality of times with the same total irradiation amount, an optical waveguide form, that is, a linear form was formed (not shown). A similar report on this result can be found in the reference (SJFrisken, “Light-induced optical waveguide uptapers,” Optics, Letters, vol. 18, no. 13, pp. 1035-1037, (1993)). That is, when the number of times of irradiation is small, there is a consistency between the report of the experimental results indicating that the region subjected to refractive index modulation tends to spread from the irradiation port (in the above-mentioned document: “uptaper”) and this example. Is recognized.

  In FIG. 2B, reference numerals 21, 22, 23, 24, and 25 denote cases where the refractive index difference Δn is 0.000, 0.002, 0.004, 0.006, and 0.008, respectively. Yes.

  FIG. 2C shows the result when signal light (wavelength: λ = 1550 nm) is propagated through the formed refractive index distribution. As is apparent from a comparison between FIG. 2C and FIG. 14B, it is possible to observe a state in which the spread of the light emitted from the optical waveguide is suppressed by the lens effect and propagates in a converged beam form. Thus, by forming a lens at the end of the optical waveguide in the photocurable resin material filling region 13, light incidence can be realized with a beam converged on an optical thin film device such as a dielectric multilayer wavelength filter device. . In FIG. 2C, reference numerals 26, 27, 28, and 29 denote cases where the relative light intensity contour lines are 0.1, 0.2, 0.3, and 0.4, respectively.

  Examples of the present invention will be described below, but the present invention is not limited to these examples. In addition, the photocurable resin material commonly used in each example is a photocurable resin material that satisfies the relationship between the irradiation light amount and the refractive index change shown in FIG. 1 with respect to the formation light (ultraviolet light having a wavelength of 600 nm or less). For example, an epoxy resin, an acrylic resin, or a resin in which these resins are mixed can be used.

[First embodiment]
In the optical circuit according to this embodiment, a dielectric multilayer wavelength filter is inserted into the groove to divide the wavelength, and the optical waveguide core in the optical waveguide core has a lens-like medium at the groove end surface. As shown in FIG. 3, the optical circuit according to the present embodiment includes an input light port 1-a, a transmitted light output port 1-b1, a reflected light output port 1-b2, a dielectric multilayer film wavelength filter 2, a photo-curing property. It has a resin material filling region 13, an input / reflected light port side 4-1 of the optical waveguide substrate 4 in the vicinity of the groove, and a transmitted light port side 4-2 of the optical waveguide substrate 4 in the vicinity of the groove. In the filling region 13, lenticular media 5-a and 5-b are formed.

  As is apparent from FIG. 3A showing the configuration of the optical waveguide circuit and the analysis coordinate system according to this embodiment, in this embodiment, the input optical port 1-a is connected to the photocurable resin material filling region 13. The emitted light is reflected by the surface of the dielectric multilayer wavelength filter 2 (λ1 in the figure) and can be efficiently optically coupled to the reflected light output port 1-b2 and transmitted through the dielectric multilayer wavelength filter 2 ( In the figure, λ2) is configured so that it can be optically coupled efficiently to the transmitted light output port. At that time, a circuit configuration in which an optical waveguide is introduced into the end face of the groove with a bending radius and angle considering suppression of bending loss and polarization dependent loss is common. In the present optical waveguide configuration, the result of studying whether or not the lens form can be realized is shown in FIG. In the figure, reference numerals 31, 32, 33, 34, and 35 indicate cases where the refractive index difference Δn is 0.000, 0.002, 0.004, 0.006, and 0.008, respectively.

First, in the first step, as shown in FIG. 3 (a), the photocurable resin is irradiated with the light formed from the input light port 1-a (ultraviolet light having a wavelength of 600 nm or less) at an irradiation light amount of 8.0 × 10 ⁻⁶ mJ. The light-curing resin material in the material filling region 13 was irradiated to form a lenticular medium. Next, as a second step, a lenticular medium was formed by irradiating the photocurable resin material in the photocurable resin material filling region 13 through the transmitted light output port 1-b2 under the same formation light conditions. Further, as a third step, a lenticular medium was formed by irradiating the photocurable resin material in the photocurable resin material filling region 13 from the reflected light output port 1-b1 under the same formation light conditions.

  As a result, as shown in FIG. 3B, it is clear that a lens-like medium having a tip spherical shape at the end face of the optical waveguide of each of the optical ports 1-a and 1-b2 and extending in the light wave propagation direction can be realized. became. (However, the lens at the waveguide end face of the transmitted light port 1-b1 is not shown in the figure.)

  FIG. 4 shows the propagation analysis result of the outgoing beam of the signal light (wavelength: λ = 1550 nm) from the waveguide end lens based on the present embodiment shown in FIG. (A) shows the refractive index profile of the formed waveguide end lens, (b) shows the propagation analysis result of the signal light in the lens-like medium, and (c) shows the phase of the signal light propagation. Each distribution analysis result is shown. In the figure, reference numerals 41, 42, 43, 44, and 45 denote cases where the refractive index difference Δn is 0.000, 0.002, 0.004, 0.006, and 0.008, and reference numerals 46, 47, Reference numerals 48, 49, 50, 51, and 52 show the cases where the relative light intensity contour lines are 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, and 0.35, respectively.

  As shown in FIG. 4B, the signal light propagating in the lenticular medium is different from the signal light propagation analysis result of FIG. Further, as is apparent from the phase distribution shown in FIG. 4C, when an equiphase surface (a line band having the same color tone in the figure) is observed, the beam propagates in a plane wave along with the propagation direction. Is observed.

  From the above results, it is clear that lenses can be formed even in an optical waveguide configuration that is actually used, and the multilayer filter characteristics can be improved with this optical coupling configuration.

[Second Embodiment]
FIG. 5 is a diagram showing an optical circuit according to a second embodiment of the present invention. FIG. 5 (a) shows the structure and a coordinate system for analysis, and FIG. 5 (b) is formed. 2 shows a refractive index distribution of a lenticular medium. In the figure, 1-a is an input light port, 1-b1 is a transmitted light output port, 1-b2 is a reflected light output port, 2 is a dielectric multilayer wavelength filter, 13 is a photocurable resin material filling region, Reference numeral 4-1 denotes the input / reflected light port side of the optical waveguide substrate 4 near the groove, 4-2 denotes the transmitted light port side of the optical waveguide substrate 4 near the groove, and 5 denotes the formed lenticular medium.

In the present embodiment, a result is shown when incoherent light is simultaneously irradiated from both the input light port 1-a and the reflected light output port 1-b2. It is assumed that the filter used at this time has almost 100% transmission characteristics for the formed light. In this example, 10.0 × 10 ⁻⁶ mJ of forming light was incident from each port as the total irradiation amount. The analysis result of the refractive index distribution of the formed lenticular medium is shown in FIG. As shown in the figure, the refractive index distribution has a form in which portions having a high refractive index are arranged in a triangular shape. Note that reference numerals 53, 54, 55, 56, and 57 in the drawing respectively show cases where the refractive index difference Δn is 0.000, 0.002, 0.004, 0.006, and 0.008.

  The lens form in the present embodiment has a function that a converged beam is obtained for the beam that passes through the filter surface, and that the reflected light beam for the filter surface can be converged on the reflected light port.

  FIG. 6 shows the beam propagation characteristics of incident / reflected signal light (wavelength: λ = 1550 nm) in a lenticular medium refractive index profile according to the second embodiment. FIGS. 6A and 6B show the incident side signal light propagation analysis results, and FIGS. 6C and 6D show the propagation state of the signal light beam reflected by the dielectric multilayer wavelength filter 2. Indicated. The light intensity contour map is shown in FIGS. 4A and 4B, and the bird's-eye view is shown in FIGS. As shown in these drawings, the signal light incident on the surface of the dielectric multilayer film wavelength filter 2 is reflected and standing waves of the reflected light and the incident light can be observed. Further, the state of propagation from the standing wave generation region to the reflected light output port 1-b2 side as reflected light is shown in the light intensity distribution contour diagram of FIG. 6C and the bird's-eye view of FIG. 6D. Indicated. As is apparent from the bird's eye view of FIG. 6D in particular, it can be observed that the reflected beam is converged as the reflected beam propagates toward the end of the optical waveguide. In the case where the relative light intensity contour lines are 0.1, 0.2, 0.3, and 0.4 with reference numerals 61, 62, 63, and 64 in FIG. 6, the reference numerals 65, 66, 67, 68, and 69 indicate The cases where the relative light intensity contour lines are 0.05, 0.1, 0.15, 0.2, and 0.25 are shown.

  From the above, it is clear that the lenticular medium according to the present embodiment improves the coupling characteristics of the filter reflected beam with the reflected light output port, which is one of the problems of the insertion type filter due to the lens form according to the present embodiment. It was revealed that the coupling efficiency can be improved.

  According to the present embodiment, it is not necessary to form light from the transmitted light output port 1-b1, and the number of processes can be reduced as compared with the first embodiment.

[Third embodiment]
FIG. 7 is a diagram for explaining a third embodiment of the present invention. FIG. 7 (a) shows a configuration and a coordinate system for analysis, and FIG. 7 (b) shows the production of the third embodiment. The refractive index distribution of the lenticular medium obtained by analysis under the conditions is shown.

  In the figure, 1-a is an input optical port, 1-b1 is a transmitted light output port, 1-b2 is a reflected light output port, 1-c is a spare port, 2 is a dielectric multilayer wavelength filter, and 13 is photocuring. 4-1 is the input / reflected light port side of the optical waveguide substrate 4 near the groove, 4-2 is the transmitted light port side of the optical waveguide substrate 4 near the groove, 5-a, 5-b , 5-c respectively indicate a lenticular medium formed at the input light port end, a lenticular medium formed at the reflected light input port end, and a lenticular medium formed by coherent light simultaneous irradiation.

In this embodiment, the result is shown when coherent light is simultaneously irradiated from both the input light port 1-a and the reflected light output port 1-b2. It is assumed that the dielectric multilayer film wavelength filter 2 used at this time has almost 100% transmission characteristics for the formed light. In this example, 6.0 × 10 ⁻⁶ mJ of formation light was incident from each port as the total irradiation amount. The refractive index distribution analysis result of the lenticular medium obtained by the analysis is shown in FIG. As shown in the figure, the refractive index distribution (5-c in the figure) of the lenticular medium was obtained not only at the optical waveguide end lenticular medium (5-a, 5-b in the figure) but also at the filter arrangement position. Note that reference numerals 71, 72, 73, and 74 in the figure respectively indicate cases where the refractive index difference Δn is 0.002, 0.004, 0.006, and 0.008.

  In the lens form according to the present embodiment, the light emitted from the input light port 1-a is collimated and the beam is converged, but spreads as the propagation distance increases. In this case, the lens structure disposed on the surface of the dielectric multilayer film wavelength filter 2 allows the beam to converge again and reach the surface of the dielectric multilayer film wavelength filter 2. Further, the beam reflected by the surface of the dielectric multilayer film wavelength filter 2 can also propagate in the reverse process.

  In this embodiment, the lenticular medium is formed on the surface of the dielectric multilayer wavelength filter 2 from two ports. However, the side of the transmitted light output port 1-b1 and the spare port 1 arranged symmetrically therewith. Needless to say, the lens shape can be formed on the surface of the dielectric multilayer film wavelength filter 2 by the incident incident light from the total four ports from c.

  Furthermore, it is possible to form a lenticular medium at an arbitrary position by adjusting the phase of light emitted from various ports.

[Fourth embodiment]
FIG. 8 is a diagram for explaining a fourth embodiment of the present invention. FIG. 8A shows a coordinate system for the configuration and analysis, and FIG. 8B shows a refractive index of the formed optical waveguide. Show the distribution. In the figure, 1-a is an input light port, 1-b1 is a transmitted light output port, 1-b2 is a reflected light output port, 2 is a dielectric multilayer film wavelength filter, 13 is a photocurable resin material filling region, Reference numeral 4-1 denotes an input / reflection light port side of the optical waveguide substrate 4 near the groove, 4-2 denotes a transmission light port side of the optical waveguide substrate 4 near the groove, and 11 denotes a self-forming optical waveguide. Note that reference numerals 81, 82, 83, 84, and 85 in the figure indicate cases where the refractive index difference Δn is 0.000, 0.002, 0.004, 0.006, and 0.008, respectively.

In this embodiment, the result is shown in the case where incoherent light is irradiated from both the input light port 1-a and the reflected light output port 1-b2 simultaneously in a plurality of times. It is assumed that the dielectric multilayer film wavelength filter 2 used at this time has almost 100% reflection characteristics with respect to the formed light. In this example, 10.0 × 10 ⁻⁶ mJ of forming light was incident in three times from each port. The analysis result is shown as FIG. As shown in the figure, a refractive index distribution in the form of an optical waveguide was obtained up to the arrangement position of the dielectric multilayer wavelength filter 2. In this optical waveguide form, the outgoing light from the input optical port 1-a propagates in the self-forming optical waveguide 11, and a beam having a propagation ray angle in the waveguide can enter the surface of the dielectric multilayer film wavelength filter 2. It becomes. Also, the beam reflected by the surface of the dielectric multilayer film wavelength filter 2 can propagate through the self-formed optical waveguide 11 in the reverse process.

  In the present embodiment, the result of forming the self-forming optical waveguide 11 up to the surface of the dielectric multilayer wavelength filter 2 by forming light input from the two ports is shown, but from the transmitted light output port 1-b1 side. It goes without saying that the formation of the self-forming optical waveguide 11 up to the surface of the dielectric multilayer wavelength filter 2 can be realized even by the incident forming light.

  According to this embodiment, since the incident light beam diameter on the surface of the dielectric multilayer wavelength filter 2 is not enlarged, a deviation that is difficult to predict from the design value of the transmission width characteristic in the filter transmission wavelength characteristic can be considered. Although improvement in the width and center wavelength characteristics cannot be expected, it is possible to improve the coupling efficiency with the beam propagating to each of the reflected light output port and the transmitted light output port.

[Fifth embodiment]
FIGS. 9-1 to 9-7 are diagrams for explaining the fifth embodiment and show an outline of a 4-channel wavelength division multiplexing optical circuit and its manufacturing process. In these drawings, FIG. 9A is a diagram for explaining the operation of the 4-channel wavelength division multiplexing optical circuit, and FIGS. 9-2 to 9-7 are diagrams for explaining the manufacturing process. In FIG. 9-2 to FIG. 9-7, the process order is shown as I → II → III as a manufacturing process. There are two basic lens forming steps, which can be classified into A type corresponding to the first, second and fourth examples and B type corresponding to the third example.

  Furthermore, since there are two types of forming light irradiation methods depending on the transmission wavelength characteristics of the filter used in the second and subsequent steps, the steps are described separately for the two types. In other words, the process in which the dielectric multilayer wavelength filter 2 to be mounted also transmits the formed light is classified as I type, and the process in the case of reflecting the formed light is classified as Type II in the text.

Accordingly, the process marking method is as follows: <(Process order: I, II, III)-(Lens formation basic process type: A, B)-(Filter type: I type, II type = 1, 2)>
It was.

  For example, when the lens-like medium shown in the first, second, and fourth embodiments is manufactured in the II step and the dielectric multilayer wavelength filter 2 transmits the formed light, <II-A- 1>.

Next, the names of the optical ports in these production process diagrams are displayed in the text and in the drawings according to the following notation.
1-a: input optical port of multiplexed wavelength signals from λ1 to λ4 (1-b1, λ1): transmitted light output port of wavelength λ1 (1-b2, λ1): reflected light output port other than wavelength λ1 or ( 1-a, λ2): input optical port to the transmission filter portion of wavelength λ2 (1-c, λ1): spare port of the transmission filter installation portion of wavelength λ1 (1-b1, λ2): transmission of wavelength λ2 Optical output port (1-b2, λ2): Reflected light output port other than wavelength λ2 or (1-a, λ3) (However, in this optical circuit configuration, the reflected light port can be an incident light port to the next stage filter section. Therefore, according to the notation method, two kinds of marks can be taken, but in the description of the present embodiment, the marks are unified with the reflected light port side number in order to avoid confusion.): Input light to the transmitted light filter unit of wavelength λ3 Port (1-c, λ2): Transparent wavelength λ2 (1-b1, λ3): Transmitted light output port of wavelength λ3 (1-b2, λ3): Reflected light output port other than wavelength λ3 or (1-a, λ4) (however, this In the optical circuit configuration, since the reflected light port can be an incident light port to the next-stage filter section, two kinds of marks can be taken according to the marking method. However, in the description of this embodiment, the reflected light port side is used to avoid confusion. The number is unified with the number.): Transmitted light output port with wavelength λ4 (However, this symbol is meaningless because there is no transmissive wavelength filter with wavelength λ4 in the figure)
(1-c, λ3): Spare port of transmission filter installation section with wavelength λ3 For dielectric multilayer wavelength filter 2 in this figure, 2-1: Transmission wavelength filter with wavelength λ1 2-2: Wavelength λ2 transmission wavelength filter 2-3: a transmission wavelength filter of wavelength λ3.

  A fifth embodiment according to the present invention will be described below in accordance with the above-described notation. First, the operation of an optical circuit that separates multiplexed signal light composed of four wavelengths λ1, λ2, λ3, and λ4 propagated from the input optical port 1-a will be described with reference to FIG. As shown in the figure, the wavelength λ1 of the 4-wavelength multiplexed signal that has propagated through the optical waveguide of the input optical port 1-a is first transmitted through the filter 2-1 and transmitted through the transmitted light output ports (1-b1, λ1). ). Wavelength signal light other than λ1 is reflected by the filter 2-1, and optically coupled to the reflected light output port (1-b2, λ1). Then, after propagating this optical waveguide, it enters the filter 2-2, transmits only the signal light of wavelength λ2, and is optically coupled to the transmitted light output port (1-b1, λ2). On the other hand, the optical signals of the other wavelengths λ3 and λ4 are optically coupled to the reflected light output port (1-b2, λ2). Similarly, after propagation through the optical waveguide, the light enters the filter 2-3 and the wavelength λ3 is optically coupled to the transmitted light output port (1-b1, λ3). Further, the reflected light of wavelength λ4 is optically coupled to the reflected light output port (1-b2, λ3).

  Through the above process, the four wavelengths λ1 to λ4 are distributed to the four ports.

  The process of sequentially manufacturing the lenticular medium described in the first, second, and fourth embodiments in each filter insertion groove is shown in FIG. 9-2 <IA> and FIG. 9-3 <II-A-1. >, FIG. 9-4 <II-A-2>, FIG. 9-5 <III-A-1>, and FIG. 9-6 <III-A-2>. As components constituting the optical circuit shown in these drawings, first to third light sources (for example, UV light source, argon laser: wavelength λ = 488 nm, green laser: wavelength λ = 532 nm, etc.) 7-1, 7-2, 7-3, optical waveguide 1 (each optical waveguide port is described above), transmission-type dielectric multilayer film wavelength filter 2-1 having wavelength λ1, and photocurable resin material filling region 13 of the transmission filter mounting portion having wavelength λ1 -1, forming light introducing terminals (type 1 and type 2) 6-1 and 6-2, an optical branching circuit 8, a variable delay optical circuit 9, an optical fiber 10, and a transmission type dielectric multilayer film wavelength filter 2 having a wavelength λ2. -2, transmission type dielectric multilayer film wavelength filter 2-3 of wavelength λ3, photocurable resin material filling region 13-2 of transmission filter mounting portion of wavelength λ2, photocuring of transmission filter mounting portion of wavelength λ3 Resin Material Filling Region 13-3 Et al constructed.

  In the following, description will be made in order from the <IA> step shown in FIG. As shown in the figure, in realizing the lenticular medium described in the first to fourth embodiments, the transmitted light output port (1-b1, λ1) having the wavelength λ1 and the wavelength multiplexed light having the wavelengths λ1 to λ4 are input. Forming light is incident from the reflected light output port (1-b2, λ1) of signal light other than the optical port 1-a and wavelength λ1, and a lenticular medium or a self-forming optical waveguide is formed at the end of the optical waveguide at each port. To do. First, before installing the dielectric multilayer wavelength filter 2-1 into the corresponding groove, in order to introduce the formed light to the reflected light output port (1-b2, λ1), the dielectric multilayer wavelength filter 2-2 The forming light introduction terminal 6-1 or 6-2 is installed in the mounting groove. That is, as the forming light introduction terminal, the optical fiber 6-1-a and the optical waveguide 6-1-b in the form of a film are optically connected, and the forming light is introduced by using a 45 ° oblique cut at the end of the optical waveguide. did. In addition, an oblique polishing fiber 6-2 in which the fiber is obliquely polished was also tried. The formation light is introduced and irradiated by these methods, the formation light irradiation light intensity in the mounting groove portion of the dielectric multilayer film wavelength filter 2-1 is measured, and the first to third formation light sources 7-1 to 7- The balance with the irradiation light intensity of 3 was adjusted. Then, the dielectric multilayer wavelength filter 2-1 is mounted in the groove and filled with the photocurable resin material, and the formation light is irradiated into the photocurable resin material in consideration of the irradiation light intensity balance. A lenticular medium corresponding to each was formed at each optical port. When forming the lens-shaped medium configuration described in the second embodiment, not all of the above-described formed light input ports are used, the formed light input from the transmitted light output port (1-b1, λ1) is canceled, and the amount of irradiation light is increased. Needless to say, this can be achieved.

  Next, the <II> process will be sequentially described. First, steps related to the filter type I type will be described. At the time of forming a lenticular medium in the transmission type wavelength filter section of wavelength λ2, as shown in step <II-A-1> in FIG. 9C, the spare port (1-c, λ1) and the reflected light output port (1- The formation light (1) is input through b2, λ2). As a result, the formation light (1) is introduced into the mounting groove of the dielectric multilayer film wavelength filter 2-2 through the dielectric multilayer film wavelength filter 2-1. Also for this, as described in the above <I> step, the irradiation light intensity is measured and adjusted before filling the mounting groove of the dielectric multilayer film wavelength filter 2-2 with the photocurable resin material. Form the formed light (2) and (3) on the other transmitted light output ports (1-b1, λ2) and reflected light output ports (1-b2, λ2), respectively, in the same manner as in step <I>. Optical input is performed, and a lenticular medium or an optical waveguide is formed in the mounting groove of the dielectric multilayer film wavelength filter 2-2.

  Next, the process <II-A-2> relating to the filter type II shown in FIG. 9-4 will be described. When the formation light (1) is reflected by the dielectric multilayer film wavelength filter 2-1, the formation light (1) is incident from the input light port 1-a of the multiplexed signal light (wavelengths λ1 to λ) and is dielectric multilayer film. After being reflected by the wavelength filter 2-1, it is introduced into the mounting portion of the dielectric multilayer film wavelength filter 2-2. For the other forming light, the forming light (2) and (3) are introduced and irradiated into the groove by the same method as in the I type.

  Step <III-A-1> and step <III-A-2> will be described with reference to FIGS. 9-5 and 9-6. In the case of the process <III-A-1> shown in FIG. 9-5, the incident light is incident from the spare port (1-c, λ2) of the forming light (2), and the dielectric multilayer film wavelength filter 2-2 and the reflected light are incident. Forming light (2) is introduced into the mounting groove of the dielectric multilayer film wavelength filter 2-3 via the output port (1-b2, λ2). Regarding the input of the formed light to the other two ports, the transmitted light output port (1-b1, λ3) and the reflected light output port (1-b2, λ3), the formed light (1) is the dielectric multilayer film wavelength filter 2 -3 transmitted light output port (1-b1, λ3). On the other hand, the formation light (3) is introduced from the reflected light output port (1-b2, λ3) and irradiated to the photocurable resin material in the groove. Needless to say, it is necessary to measure and adjust the irradiation light intensity before the photocurable resin material is injected into the mounting groove of the dielectric multilayer wavelength filter 2-3 when introducing the forming light in this case.

  Next, step <III-A-2> will be described with reference to FIG. Since this process is a case where the dielectric multilayer film wavelength filters 2-1 and 2-2 reflect the formed light, the formed light (1) is incident from the input optical port 1-a and the dielectric multilayer film wavelength filter 2 is incident. After being reflected at −1, 2-2, it is introduced into the mounting groove of the dielectric multilayer film wavelength filter 2-3. Other formation lights (2) and (3) are the same as those in the above-described step <III-A-1>.

  Next, the specific formation process (lens formation basic process B type) of the lenticular medium described in the third embodiment will be described as a process <IB> based on FIG. 9-7.

  In the third embodiment, the lens-shaped medium forming step includes forming light (1) from the input light port 1-a, forming light (1) ′ from the reflected light output port (1-b2, λ1), and transmitted light output port ( 1-b1, λ1) from the formed light (1) ″ to maintain the phase relationship and form a lenticular medium. Therefore, the same forming light source 7-1 is split into three ports by the optical branch circuit 8. After the optical branching, the phase of each optical path (forming light (1), forming light (1) ′ and forming light (1) ″ in the figure) is matched using the variable delay optical circuit 9 in each optical path. Make adjustments. In the adjustment process, after the light receiving element is temporarily installed (not shown) at the same position where the filter is installed before being installed in the groove of the dielectric multilayer wavelength filter 2, the maximum light is generated as a result of interference between the formed lights emitted from all the optical paths. The variable delay optical circuit 9 is adjusted so that the intensity can be detected. Next, in place of the light receiving element, the dielectric multilayer film wavelength filter 2-1 is mounted in the groove, and the photocurable resin material is injected and filled. From the end of the optical waveguide groove to the photocurable resin material with the set delay amount as described above. Each of the end faces of the transmitted light output port (1-b1, λ1), the reflected light output port (1-b2, λ1), and the input light port (1-a, λ1), which are three optical ports, is irradiated In addition, a lens can be formed on the filter mounting surface.

  Also in the process, the steps <II-A-1>, <III-A-1>, <II-A-2>, <III are the same as the lenticular medium forming steps according to the first, second, and fourth embodiments. In order to realize the process through the same process type as that of -A-2>, the description of the next post-process by the basic process B will be omitted.

  Although the manufacturing process has been described above by taking the 4-channel wavelength division multiplexing optical circuit as an example, it is clear that the channel scale and the like are not limited to this embodiment.

[Sixth embodiment]
FIG. 10 is a diagram for explaining the sixth embodiment, in which FIG. 10 (a) is a top view of the rhombic structure groove according to the filter fixing method and the configuration between the filter and the optical waveguide according to this embodiment. ) Is a cross-sectional view showing a cross-section along the line aa ′, FIG. 10C is a top view of a substrate-cut type showing details of part A in FIG. It is a top view of a type | mold. In the figure, 1-a is an input optical port, 1-b1 is a transmitted light output port, 1-b2 is a reflected light output port, 1-c is a spare port, 2 is a dielectric multilayer wavelength filter, and 13 is photocuring. 3-4 is a rhombus groove, and 3-5 is a filter groove. Here, iii-iii ′ coincides with the end face shown in FIG. FIG. 11 is a diagram for explaining the difference in the self-forming lens structure obtained by the difference in the shape of the end face of the optical waveguide core in the vicinity of the groove shown in FIGS. 10 (c) and 10 (d). FIG. 10B shows a self-forming lens obtained when the surface is cut obliquely with respect to the optical waveguide propagation direction (substrate cut type shown in FIG. 10C). FIG. 10 shows a self-forming lens obtained when cut in the vertical direction (the optical waveguide end face cut type shown in FIG. 10D). In FIG. 11, reference numerals (111, 116), (112, 117), (113, 118), and (114, 119) indicate that the refractive index difference Δn is 0.002, 0.004, 0.006, 0. The case of 008 is shown respectively.

  The sixth embodiment will be described below with reference to the drawings. In the filter insertion type wavelength division multiplexing optical circuit shown in FIG. 13 as a conventional example, the insertion groove is formed in a linear groove shape by a dicing saw or the like. For this reason, the lateral position of the filter is not accurately determined when the groove of the filter is inserted, and the filter is tilted, and it is difficult to accurately determine the positional relationship with the optical waveguide. Therefore, as shown in FIG. 10, by forming grooves in the rhombus structure by reactive ion etching, the dielectric multilayer wavelength filter 2 is inserted in the diagonal position so as to face the optical waveguide, and dielectric The body multilayer wavelength filter 2 can be prevented from falling down and the position can be determined accurately. The temporary fixing of the dielectric multilayer film wavelength filter 2 was realized by the filter groove 3-5 provided on the bottom surface of the rhombic groove.

  Next, the effect on the lens shape due to the difference in the shape of the end face of the optical waveguide core at the end face of the rhombic groove of the optical waveguide will be described. FIGS. 10C and 10D show the positional relationship between the optical waveguide propagation direction and the groove end surface. As shown in FIG. 10, the substrate cut type (a) and the optical waveguide propagation direction vertical cut type are shown. The state of propagation of the formed light differs between (d) and (d). In the figure, the wavefront propagating through the optical waveguide is indicated by a double line as <ii ′> → <ii-ii ′> → <iii−iii ′>. In the substrate cut type shown in FIG. 10C, when viewed on the wg-a to wg-b side and the wg-a 'to wg-b' side of the optical waveguide 1-a, It can be seen that there is a phase difference on both sides of the wavefront propagating to (iii-iii 'in the figure). On the other hand, in the optical waveguide propagation direction vertical cut type shown in FIG. 10 (d), when propagation starts from the optical waveguide 1-a into the photocurable resin material, the side of wg-a to wg-b and wg-a 'to wg. When viewed from the -b 'side, the wavefront (iii-iii' in the figure) coincides at the end face of the optical waveguide, and when viewed from both sides, no phase difference occurs, high symmetry, and good directivity. It can be expected that a lens configuration can be realized.

  FIG. 11 shows the difference in the shape of the lenticular medium due to the difference in the shape of the end face of the optical waveguide core. In the substrate cut type optical waveguide form, the substrate cut type (see FIG. 10C) and the optical waveguide propagation direction are affected by the effect of starting the irradiation of the forming light from the wg-b portion (see FIG. 10C). Compared with the vertical cut type (see FIG. 10 (d)), the substrate cut type has a larger bulge on the wg-b side, and the symmetry and directivity with respect to the beam propagation direction are perpendicular to the optical waveguide propagation direction. You can see that it is bad compared to the mold. Therefore, by forming the groove end face in a plane perpendicular to the propagation direction of the optical waveguide, a light beam having high directivity and good symmetry can be obtained.

  FIG. 12 shows a configuration in which functions are further given to the rhombic groove structure described in FIG. As described in the description of the present embodiment, it is possible to prevent the filter from falling by realizing the rhombic groove structure, and further, by adjusting the side angle (θ in the figure) constituting the rhombic groove, the optical waveguide It has been shown that the lens structure formed in the core part can be made with good symmetry. However, there are cases where it is difficult to insert a filter with a filter size that can be gripped at the filter insertion diagonal portion of the rhombic groove structure only by extending the sides constituting the rhombus structure groove. This is because the width of the filter in the figure is larger than the width w in the figure.

  On the other hand, if a sufficient rhombus diagonal length (L in the figure) is provided, the distance from the end of the optical waveguide to the filter surface also increases, and it becomes difficult to design an optical coupling system using a self-forming lens or a self-forming optical waveguide. did. Therefore, as shown in FIG. 12, rectangular grooves 3-6 having the same size as the filter are manufactured by reactive ion etching in the diagonal portion of the rhombic groove structure, and the filter size limit in the rhombus structure described in FIG. Can be avoided sufficiently.

  As described above, the embodiments so far have been described with respect to the dielectric multilayer wavelength filter. However, as a matter of course, the present invention is not limited only to the dielectric multilayer wavelength filter, Needless to say, the present invention can also be applied to other optical thin film components such as metal mirrors, magnetic thin films, and wave plate filters.

  INDUSTRIAL APPLICABILITY The present invention is useful when applied to optical parts optical coupling technology and optical waveguide circuit construction technology for information communication processing devices such as ubiquitous communication.

It is a characteristic view which shows the irradiation light quantity dependence of the refractive index change of a photocurable resin material. It is a figure which shows the formation result of a waveguide end spherical lens common to the Example of this invention, and the mode of propagation | transmission of signal light, (a) is explanatory drawing which shows the structure and analysis coordinates, (b) Is a characteristic diagram showing the refractive index distribution of the lenticular medium, and (c) is a characteristic chart showing the signal light propagation characteristic in the refractive index distribution of the lenticular medium. 1A and 1B are diagrams illustrating an optical circuit according to a first embodiment, where FIG. 3A is an explanatory diagram illustrating the configuration and analysis coordinates, and FIG. 2B is a characteristic diagram illustrating a refractive index distribution of the lens-shaped medium. FIG. 6 is a characteristic diagram showing the refractive index distribution of the optical circuit according to the first embodiment and the state of signal light propagation, where (a) shows the refractive index distribution characteristic of the formed waveguide end lens, and (b) shows the signal light propagation. The propagation analysis characteristics in the lenticular medium and (c) show the phase distribution analysis characteristics of the signal light propagation. It is a figure which shows the optical circuit based on 2nd Example, (a) is explanatory drawing which shows the structure and analysis coordinate, (b) is a characteristic view which shows the refractive index distribution of the lenticular medium. FIG. 6 is a characteristic diagram showing the result of beam propagation analysis in the lens configuration of the optical circuit according to the second example. FIGS. 6A and 6B show the incident side signal light propagation analysis characteristics, and FIGS. In (d), the propagation characteristics of the signal light beam reflected by the dielectric multilayer film wavelength filter 2 are shown. It is a figure which shows the optical circuit based on 3rd Example, (a) is explanatory drawing which shows the structure and analysis coordinate, (b) is a characteristic view which shows the refractive index distribution of the lenticular medium. It is a figure which shows the optical circuit based on 4th Example, (a) is explanatory drawing which shows the structure and analysis coordinate, (b) is a characteristic view which shows the refractive index distribution of the optical waveguide. It is a figure which shows the optical circuit which concerns on 5th Example, It is explanatory drawing which shows the structure of a 4-channel wavelength division multiplexing optical circuit. It is a figure which shows the manufacturing process of the optical circuit which concerns on 5th Example, and is explanatory drawing which shows process pattern IA. It is a figure which shows the manufacturing process of the optical circuit which concerns on 5th Example, and is explanatory drawing which shows process pattern II-A-1. It is a figure which shows the manufacturing process of the optical circuit which concerns on 5th Example, and is explanatory drawing which shows process pattern II-A-2. It is a figure which shows the manufacturing process of the optical circuit which concerns on 5th Example, and is explanatory drawing which shows process pattern III-A-1. It is a figure which shows the manufacturing process of the optical circuit which concerns on 5th Example, and is explanatory drawing which shows process pattern III-A-2. It is a figure which shows the manufacturing process of the optical circuit which concerns on 5th Example, and is explanatory drawing which shows process pattern IB. It is a figure explaining 6th Example, The figure (a) is a top view of the rhombus structure groove | channel concerning the structure between a filter fixing method and a filter-optical waveguide by a present Example, The figure (b) is the a FIG. 4C is a top view of a substrate cut type showing the details of part A of FIG. 4A, and FIG. 3D is a top view of a vertical cut type in the optical waveguide propagation direction. is there. It is a figure which shows the analysis result of 6th Example, and Fig.10 (a) is a characteristic view which shows refractive index distribution corresponding to FIG.10 (c) and FIG.10 (b), respectively. The top view which shows the other example of the said rhombus structure groove | channel, (b) is the aa 'line sectional drawing. It is a perspective view which shows the structure of the wavelength division multiplexing optical circuit which concerns on a prior art. FIG. 14 is a top view of the wavelength division multiplexing optical circuit shown in FIG. 13. FIG. 14 is a characteristic diagram showing an analysis result of the wavelength division multiplexing optical circuit shown in FIG. 13, (a) is a photocurable resin material refractive index distribution characteristic, (b) is a signal light propagation analysis characteristic, and (c) is a signal light propagation characteristic. The propagation analysis phase distribution characteristics are shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical waveguide 1-a Input light port 1-b1 Transmitted light output port 1-b2 Reflected light output port 1-c Spare port 2, 2-1, 2-2, 2-3 Dielectric multilayer wavelength filter 3-4 Diamond groove 3-5 Filter groove 3-6 Rectangular groove 4 Optical waveguide substrate 4-1 Input / reflected light port side 4-2 Transmitted light port side 5, 5-a, 5-b, 5-c Formation of lenticular medium 6 Light Introducing Terminal 6-1 Waveguide-Type Forming Light Introducing Terminal 6-1-a Optical Fiber 6-1-b Optical Waveguide 6-2 Obliquely Polished Optical Fiber 7-1, 7-2, 7-3 Light Source for Formation 8 Branch circuit 9 Delay optical circuit 10 Optical fiber 11 Self-forming optical waveguide 13, 13-1, 13-2, 13-3 Photocurable resin material filling region

Claims (12)

An optical thin film that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed by a photocurable resin material that fills the grooves;
The core portion end of the optical waveguide facing the inner surface of the groove by propagating and radiating forming light having a wavelength that gives a refractive index change to the photocurable resin material to the photocurable resin material through the optical waveguide Or a lens structure formed in the vicinity of the surface of the optical thin film placed in the groove. A dielectric multilayer wavelength filter that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed by a photocurable resin material that fills the grooves;
The core portion end of the optical waveguide facing the inner surface of the groove by propagating and radiating forming light having a wavelength that gives a refractive index change to the photocurable resin material to the photocurable resin material through the optical waveguide Or a lens structure formed in the vicinity of the surface of the dielectric multilayer film wavelength filter installed in the groove. An optical thin film that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed by a photocurable resin material that fills the grooves;
The optical waveguide facing the inner surface of the groove by propagating and radiating forming light having a wavelength that gives a refractive index change to the photocurable resin material to the photocurable resin material at least twice through the optical waveguide. And an optical waveguide core structure formed from the core portion to the optical thin film or the vicinity thereof. A dielectric multilayer wavelength filter that is inserted into one or more grooves provided in the optical waveguide substrate and positioned and fixed by a photocurable resin material that fills the grooves;
The core portion of the optical waveguide facing the inner surface of the groove by propagating and irradiating the photocurable resin material with a wavelength that gives a refractive index change to the photocurable resin material through the optical waveguide And an optical waveguide core structure formed to the dielectric multilayer wavelength filter or the vicinity thereof. In the optical circuit according to claim 1 or 3,
An optical circuit characterized in that a groove in a filling region filled with a photocurable resin material has a rhombus structure, and an optical thin film is inserted and fixed at a diagonal position. In the optical circuit according to claim 2 or 4,
An optical circuit characterized in that a groove shape of a filling region filled with a photocurable resin material has a rhombus structure, and a dielectric multilayer film wavelength filter is inserted and fixed at a diagonal position thereof. In a method for manufacturing an optical circuit, in which an optical thin film is inserted into one or more grooves provided in an optical waveguide substrate,
The optical thin film is positioned and fixed in the groove, and the forming light having a wavelength that changes the refractive index of the photocurable resin material is formed from the optical waveguide in the groove filled with the photocurable resin material. Propagating and radiating into the groove once to form a lens structure in the vicinity of the core portion end of the optical waveguide facing the inner surface of the groove or the surface of the optical thin film installed in the groove,
Thereafter, the light-curing resin material in a portion excluding the lens structure forming portion is subjected to light irradiation with an intensity capable of polymerization, irradiation with other wavelength light, or a heat treatment step on the entire light-curing resin material, A method for producing an optical circuit, comprising: solidifying a photocurable resin material as a whole and optically positioning and fixing an optical thin film inserted into the groove and the optical waveguide. In a manufacturing method of an optical circuit formed by inserting a dielectric multilayer wavelength filter into one or more grooves provided in an optical waveguide substrate,
Positioning and fixing the dielectric multilayer film wavelength filter in the groove, and forming light having a wavelength that gives a refractive index change to the photocurable resin material in the groove filled with the photocurable resin material. In the vicinity of the end of the core portion of the optical waveguide facing the inner surface of the groove or the surface of the dielectric multilayer wavelength filter installed in the groove by being propagated and emitted once into the groove from the optical waveguide Forming the lens structure,
Thereafter, the light-curing resin material in a portion excluding the lens structure forming portion is subjected to light irradiation with an intensity capable of polymerization, irradiation with other wavelength light, or a heat treatment step on the entire light-curing resin material, A method for producing an optical circuit, comprising: solidifying a photocurable resin material as a whole, and optically positioning and fixing a dielectric multilayer wavelength filter inserted in the groove and the optical waveguide. In a method for manufacturing an optical circuit, in which an optical thin film is inserted into one or more grooves provided in an optical waveguide substrate,
The optical thin film is positioned and fixed in the groove, and the forming light having a wavelength that changes the refractive index of the photocurable resin material is formed from the optical waveguide in the groove filled with the photocurable resin material. By propagating and radiating twice or more into the groove, an optical waveguide core structure is formed from the core portion end of the optical waveguide facing the inner surface of the groove to the optical thin film or the vicinity thereof,
Thereafter, the entire photocurable resin material is subjected to light irradiation with a strength capable of polymerizing the portion of the photocurable resin material excluding the optical waveguide core structure forming portion, irradiation with other wavelength light, or a heat treatment step. A method for producing an optical circuit, comprising: solidifying the photocurable resin material as a whole and optically positioning and fixing the optical thin film inserted into the groove and the optical waveguide. In a manufacturing method of an optical circuit formed by inserting a dielectric multilayer wavelength filter into one or more grooves provided in an optical waveguide substrate,
Positioning and fixing the dielectric multilayer film wavelength filter in the groove, and forming light having a wavelength that gives a refractive index change to the photocurable resin material in the groove filled with the photocurable resin material. Optical waveguide core structure from the optical waveguide core end facing the inner surface of the groove to the dielectric multilayer wavelength filter or the vicinity thereof by propagating and radiating into the groove from the optical waveguide twice or more Form the
Thereafter, the entire photocurable resin material is subjected to light irradiation with a strength capable of polymerizing the portion of the photocurable resin material excluding the optical waveguide core structure forming portion, irradiation with other wavelength light, or a heat treatment step. A method for producing an optical circuit comprising: solidifying the photocurable resin material as a whole, and optically positioning and fixing the dielectric multilayer film wavelength filter inserted in the groove and the optical waveguide. In the manufacturing method of the optical circuit as described in any one of Claim 7 thru | or 10,
In order to introduce the formation light into the groove filled with the photocurable resin material, the groove filled with the photocurable resin material and the photocurable resin material connected by the optical waveguide to the groove before filling. A film-type optical waveguide circuit obliquely processed at an angle of approximately 45 degrees or an optical fiber obliquely processed at an angle of approximately 45 degrees is inserted into the groove portion before filling with the photocurable resin material to form light. An optical circuit manufacturing method comprising introducing and irradiating the groove. In the manufacturing method of the optical circuit of Claim 1 or Claim 2,
In forming the lens structure in the groove filled with the photo-curable resin material, the coherent forming light is introduced using at least two or more ports of the optical waveguide substrate to form the plurality of ports. A method of manufacturing an optical circuit, wherein a lens structure is formed at an arbitrary position in a groove filled with the photo-curing resin material by causing phase interference of light.

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