JP2004264868A - Waveguide type optical functional device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waveguide type optical functional device capable of reducing connection loss by inserting an optical device. <P>SOLUTION: The waveguide type optical functional device has a wavelength filtering function, and is provided, on a waveguide substrate 101, with an input waveguide 102, an output waveguide 103, a slab waveguide 104, a trench structure 105a of which the side face is a curved surface of which the normal resides in the waveguide face, a high-reflection mirror 105b made of a dielectric multi-layer film formed on a polymer film, a trench structure 107 of which the side face is a curved surface of which the normal resides in the waveguide face, and a wavelength filter 108. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a waveguide-type optical functional element, and in particular, a waveguide-type optical element suitable for application to a wavelength multiplexer / demultiplexer for optical communication, an optical isolator, an interference measurement device, and an optical switch for optical communication. It relates to a functional element.

  FIG. 33 is a cross-sectional view showing the configuration of a conventional waveguide-type optical functional device. In this example, a groove is formed in a waveguide, and various optical elements are inserted into the groove to constitute a waveguide type optical functional element. An optical element 205 is inserted into a groove of a waveguide in which a lower cladding layer 204, a core layer 203, and an upper cladding layer 202 are sequentially formed on a waveguide substrate 201, and is bonded and fixed with a refractive index matching transparent adhesive 206. It is.

  FIG. 34 is a top view showing the configuration of another conventional waveguide type optical function element. In this example, a groove is formed in a waveguide, metal is deposited, and the end face is used as a reflection surface. A groove structure 208 is formed in the single mode waveguide 207, and a metal coating 209 is applied inside the groove structure 208. The groove structure 208 functions as a total reflection mirror without the metal coating 209 when the light incident angle is large.

  FIG. 35 is a top view showing the configuration of a conventional interference measurement optical system. In this interference measurement optical system, a half mirror 302, a movable mirror 303, and an interference pattern observation surface 304, which are individual optical components, are spatially arranged, and coherent illumination light 301 from a light source such as a laser is split by the half mirror 302. Then, one is reflected by the movable mirror 303, the other is reflected by the observation object, and combined by the half mirror 302 to observe the interference on the observation surface of the interference pattern to measure the distance to the observation object, For example, measuring the shape of the surface of an object. In actual measurement, the movable mirror 303 is finely moved with an electric stage or the like for variable control of one of the optical path lengths, which is used for distance measurement and the like.

FIG. 36 is a top view showing the configuration of a conventional Mach-Zehnder interference optical switch composed of optical waveguides. The Mach-Zehnder interference optical switch splits the input light input to the input waveguide 305 into two by a 1: 2 optical branch circuit 306, and controls the refractive index by a refractive index control unit 307 to control the optical path length. The other is variably controlled, and the other is directly input to and coupled to the 2: 1 optical coupling circuit 309 via the waveguide 308 and output from the output waveguide 310. By controlling the phase difference of the light propagating through the two arms forming the Mach-Zehnder interference system, the light intensity coupled to the output waveguide 310 is controlled. That is, in a quartz-based waveguide, the amount of heat generated from the thin-film heater on the waveguide substrate is controlled to control the refractive index of the waveguide, thereby realizing a switching operation. Alternatively, in a semiconductor waveguide, the switch operation is realized by controlling the refractive index of the waveguide by controlling the amount of current injected into the waveguide and the electric field intensity. Alternatively, in the LiNbO ₃ waveguide, a traveling-wave-type electrode is provided, and the refractive index of the waveguide is controlled by controlling the electric field intensity while performing phase matching between the applied electric field by the electric signal and the propagating light. Implement switch operation.

  However, in the example shown in FIG. 33, there is a problem that the connection loss sharply increases as the groove width s increases. Further, in the example shown in FIG. 34, there is a problem that the scattering loss or the connection loss becomes extremely large unless the reflection end face is made smooth and vertical. Further, in the example shown in FIG. 35, the reliability of the variable control of the optical path length is low due to the low reliability of the mechanical driving portion, and further, it is difficult to assemble the device compactly. . In the example shown in FIG. 36, the refractive index control amount is about 0.001 regardless of which of the thermal effect, the current injection (plasma effect), and the electric field effect is used. Therefore, in order to realize a phase difference of π required for the switch operation, a refractive index control waveguide having a length of about 1000λ (λ is a wavelength) is required. Further, in a high-speed switch, since a high electric field cannot be used, the amount of refractive index control is reduced, a refractive index control waveguide having a length of about 5000λ is required, and phase matching between the traveling wave electric field and the propagating light is indispensable. Become. Since these refractive index control waveguides have a minimum bending radius of a few millimeters in general and are constituted by straight waveguides, their dimensions are large. That is, it is difficult to reduce the size of the conventional Mach-Zehnder interference optical switch, and phase matching is indispensable for high-speed modulation.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention reduces a connection loss due to insertion of an optical element, and can form a waveguide waveguide light having a small propagation loss and a large propagation optical path length in a short length region. It is intended to provide a functional element.

  The waveguide type optical functional device of the present invention includes a substrate holding an optical waveguide, and a curved groove structure formed on the substrate and having a curved surface having a normal line in the optical waveguide surface as a side surface.

  Further, the optical device further includes a planar groove structure formed on the substrate and having a side surface facing a plane whose normal is in the plane of the optical waveguide, and an optical element inserted in the curved groove structure or the planar groove structure. Thus, it can be applied to a wide range of optical element applications.

  Further, an input waveguide on which input light is incident, a slab waveguide on which light from the input waveguide is incident, a first curved groove structure provided in the slab waveguide, and A first to an n-th (n ≧ 1) planar groove structure into which light from the first curved groove structure is incident, and the i-th (i is 1 ≦ i ≦ n) provided in the slab waveguide. Any one of the following): a second curved groove structure on which light from the planar groove structure is incident; and an output waveguide on which light from the second curved groove structure is incident and emits output light. Can be suppressed within a plane, and the loss can be reduced.

  In addition, the optical element inserted into the curved groove structure is a dielectric film, a metal film, or a semiconductor film formed on a flexible film, so that the accuracy can be increased with a simple configuration. .

  Further, by further providing a substrate coated with a dielectric multilayer film inserted in at least one of the planar groove structures, reflected light can be reduced and loss can be reduced.

  Further, by further providing a flat ferromagnetic material inserted in at least one of the planar groove structures, the polarization direction of light can be changed with a simple configuration.

  Further, by further providing a columnar or cylindrical lens-shaped ferromagnetic material inserted in at least one of the planar groove structures, light diffusion can be suppressed and loss can be reduced.

  Further, by further providing a ferromagnetic material having a spherical shape, a hemispherical shape, or a shape having a rotationally symmetric surface inserted in at least one of the planar groove structures, it is possible to further suppress light diffusion and reduce loss. .

  Further, by further including a polarizing filter plate inserted in at least one of the planar groove structures, the polarization direction of light can be changed with a simple configuration.

  Further, by further including a polarization separating mirror plate and a half-wave plate inserted into at least one of the planar groove structures, a polarization independent waveguide optical isolator can be realized with a simple configuration. .

  Further, since the input waveguide and the output waveguide are composed of a plurality of optical waveguides, a large number of optical isolators can be integrated in a small size.

  Further, the waveguide type optical functional device of the present invention includes a substrate holding the optical waveguide, a first optical waveguide and a second optical waveguide formed on the substrate, and the first optical waveguide formed on the substrate. A reflection structure for arranging and coupling the first coupling end of the waveguide and the second coupling end of the second optical waveguide to positions that are in an image forming relationship with each other;

However,
w1: mode field radius at the first coupling end A w2: mode field radius at the beam waist of the one-dimensional Gaussian beam in the slab waveguide after mirror reflection L1: point B where the reflection structure and the optical axis intersect with the first coupling end A L2: distance between the beam waist position of the one-dimensional Gaussian beam in the slab waveguide after mirror reflection and point B R: curvature near point B neff: effective refractive index of a portion where light propagates LW: Assuming the wavelength of light, the second coupling end C is located at a distance L2 from the point B, and the mode field radius of the second waveguide is equal to w2. Thereby, it is possible to suppress a decrease in coupling efficiency in the reflection structure having a small radius of curvature.

  Further, the waveguide type optical functional device of the present invention comprises a substrate on which an optical waveguide is held, and a plurality of curved groove structures formed on the substrate, the normal of which is a curved surface within the optical waveguide surface. And a delay control area for controlling a delay amount of the optical path by providing a plurality of optical paths by changing the optical path by the curved groove structure in the substrate.

  Further, since the curved groove structure is two curved groove structures having an uneven relationship with each other across the optical waveguide core, the waveguide can be bent with a small loss and a small curvature.

  Further, the waveguide optical function element is used as a delay control waveguide, a 2: 2 optical coupling circuit having a first output terminal connected to an input terminal of the delay control waveguide, and an output terminal of the delay control waveguide. , An output waveguide connecting the second output end of the 2: 2 optical coupling circuit to the substrate end, and an input waveguide connecting the input end of the 2: 2 optical coupling circuit to the substrate end , The size of the interference measurement device can be reduced.

  Further, the waveguide optical function element is used as a delay control waveguide, a 2: 2 optical coupling circuit having a first output terminal connected to an input terminal of the delay control waveguide, and an output terminal of the delay control waveguide. A coupling structure, an output waveguide for connecting a second output terminal of the 2: 2 optical coupling circuit to a substrate end, and output terminals for first and second input terminals of the 2: 2 optical coupling circuit, respectively. Are connected, and a plurality of input waveguides respectively connecting a plurality of input ends of the first and second wavelength multiplexer / demultiplexers to a substrate end, Measurement can be performed accurately for a plurality of different wavelengths.

  Further, the waveguide optical function element is used as a delay control waveguide, and further, a first wavelength multiplexer / demultiplexer whose output ends are connected to input ends of the plurality of delay control waveguides, respectively, A reflection structure connected to each output terminal; a 2: 2 optical coupling circuit having a first output terminal connected to an input terminal of the first wavelength multiplexer / demultiplexer; and a second output of the 2: 2 optical coupling circuit. An output waveguide having an end connected to the substrate end; second and third wavelength multiplexer / demultiplexers having output ends connected to first and second input ends of the 2: 2 optical coupling circuit; And the input waveguides that connect the plurality of input ends of the third wavelength multiplexer / demultiplexer to the substrate end, respectively, so that the delay time of light from different light sources can be separately controlled to improve measurement accuracy.

  Further, the above-mentioned waveguide optical function element is used as a delay control waveguide, and two 2: 2 optical coupling circuits each having a first output terminal connected to an input terminal of each of the two delay control waveguides; A reflection structure connected to an output terminal of the delay control waveguide, a wavelength multiplexer / demultiplexer having first and second input terminals connected to a second output terminal of the 2: 2 optical coupling circuit, respectively, Providing an output waveguide for connecting the output end of the multiplexer / demultiplexer to the substrate end and an input waveguide for connecting the input end of the 2: 2 optical coupling circuit to the substrate end, respectively, enables light from different light sources to be provided. The measurement accuracy can be improved by separately controlling the delay times.

  Further, a 1: 2 optical branch circuit in which the first and second output terminals are connected to the input terminals of the two delay control waveguides, using the waveguide optical function element as a delay control waveguide; An input waveguide connecting the input end of the two-optical branch circuit to the substrate end, a 2: 1 optical coupling circuit having first and second input ends connected to the output ends of the two delay control waveguides, 1: 1 optical coupling circuit and an output waveguide that connects the output end of the optical coupling circuit to the end of the substrate, thereby making it possible to reduce the size of the Mach-Zehnder interference optical switch.

  A first 2: 2 optical coupling circuit in which first and second output terminals are connected to input terminals of the two delay control waveguides, using the waveguide optical function element as a delay control waveguide; An input waveguide connecting the input end of the first 2: 2 optical coupling circuit to the substrate end, and a second input waveguide connecting the first and second input ends to the output ends of the two delay control waveguides. : 2 optical coupling circuit and an output waveguide for connecting the output end of the second 2: 2 optical coupling circuit to the substrate end to reduce the size of the Mach-Zehnder interference type optical switch for switching the output end. it can.

  In addition, a 2: 2 optical coupling circuit in which the first and second output terminals are connected to the input terminals of the two delay control waveguides, using the waveguide optical function element as a delay control waveguide; By providing an input waveguide that connects the input end of the two-optical coupling circuit to the substrate end, and a reflection structure that is connected to each of the output ends of the two delay control waveguides, the light is transmitted twice by the delay control waveguide. Therefore, the same effect can be obtained with a half optical path length, which is effective for downsizing the element.

  Further, the waveguide optical function element is used as a delay control waveguide, and further, first and second output terminals are connected to input terminals of first and second delay waveguides, at least one of which is the delay control waveguide. A 1: 2 optical branching circuit, an input waveguide connecting an input end of the 1: 2 optical branching circuit to a substrate end, and an output waveguide connected to output ends of the first and second delay waveguides, respectively. First and second reflecting structures for collimating the emitted light, a part of the parallel light from the first reflecting structure is reflected to an observation object, and a part of the parallel light from the second reflecting structure from the opposite side is received. A semi-transparent mirror that reflects off the array and transmits a part of the parallel light from the observation object to the light receiving array, receives parallel light from the observation object that passes through the semi-reflection mirror, and reflects the semi-reflection mirror. And an optical receiver array that receives parallel light from the incoming second reflecting structure. In one scan changing the delay amount, since it is measured at each point in the interval of one dimension, it is possible to speed up the measurement.

  The following is a brief description of an effect obtained by a representative one of the inventions disclosed in the present application.

  The first effect is that a low-loss reflection structure can be provided in the slab waveguide by inserting a high-reflection mirror deposited on a flexible film into the groove structure.

  The second effect is that, by integrating optical components having an effect proportional to the substrate thickness (for example, a Faraday element, a wave plate, etc.) into the waveguide while keeping the total thickness of the substrate constant, integration is achieved. It is possible to reduce the accompanying loss.

  The third effect arises from the first effect. A wide parallel beam (having a large spot diameter) is formed with low loss in the slab waveguide, and the parallel beam propagates in the slab waveguide through which the parallel beam propagates. By inserting the optical component into the groove structure provided in the above, it is possible to reduce the loss when the light passes through the groove portion where the waveguide does not exist and the optical component portion and is coupled to the waveguide again.

  The fourth effect is that a material such as YIG having a Faraday effect is processed into a columnar or spherical shape to have a lens function, so that these materials can be hybrid-integrated in a waveguide with low loss.

  The following macro effects are produced by utilizing these first to fourth micro effects in various optical waveguide circuits.

  A fifth effect is that a waveguide-type optical isolator and an optical wavelength filter with low loss can be configured. The waveguide type isolator is smaller than the conventional isolator using micro optics, and its effect is remarkable especially when it is formed into an array. Further, if an isolator can be incorporated in the waveguide, it becomes possible to operate a laser or an amplifier integrated in the waveguide circuit stably. Further, if the present invention is applied to a small-scale wavelength multiplexing / demultiplexing circuit, a wavelength multiplexing / demultiplexing circuit smaller in size and lower in loss than a conventional arrayed waveguide grating can be realized.

  The sixth effect is that an extremely long delay line can be mounted on the waveguide substrate, so that an interference optical system, which has conventionally been configured by disposing individual components, can be configured on the waveguide substrate. In addition, since the delay control amount is large, it is easy to measure the uneven shape having a step without mechanically driving the mirror.

  The seventh effect is that an extremely long delay line can be mounted on the waveguide substrate, so that an optical switch driven by controlling the temperature of the entire chip can be configured.

  An eighth advantage is that the optical switch can be miniaturized because the delay line can be bent and mounted on the waveguide substrate and compactly mounted.

  The ninth effect is that the delay line can be folded on the waveguide substrate and mounted compactly, so that the drive voltage of the optical switch can be reduced.

  A tenth advantage is that the delay line can be folded on the waveguide substrate and mounted compactly, so that the phase matching between the high-frequency electric field for driving the optical switch and the propagation light becomes unnecessary, and the switch configuration is simplified.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In all the drawings for describing the embodiments, components having the same function are denoted by the same reference numerals, and a repeated description thereof will be omitted.

  FIG. 1 is a top view showing the configuration of the waveguide-type optical functional device according to the first embodiment of the present invention. The present waveguide type optical functional element has a wavelength filter function, and has a waveguide substrate 101, an input waveguide 102, an output waveguide 103, a slab waveguide 104, and a curved surface having a normal line within the waveguide surface as a side surface. Groove structure 105a, a high-reflection mirror 105b made of a dielectric multilayer film formed on a polymer film, a groove structure 107 whose side faces a plane whose normal line lies in the waveguide plane, and a wavelength filter plate 108. Further, in order to match the shape of the mirror surface to the groove, a minute pressing object 118 may be inserted.

  FIG. 2 is a cross-sectional view showing details around the high-reflection mirror according to the first embodiment. The high-reflection mirror 105b includes a high-reflection mirror film 109 composed of a dielectric multilayer film and a flexible polymer film substrate 110 holding the high-reflection mirror film 109, and has an adhesive having a refractive index substantially equal to that of the waveguide. 111 inserts into the groove structure 105a formed in the upper clad layer 112, the core layer 113, and the lower clad layer 114, and is adhesively fixed. The groove of the groove structure 105a has a groove width of about 20 to 30 μm and a groove depth of about 20 to 50 μm. Examples of the polymer film substrate 110 include a polyimide substrate, a cellulose triacetate substrate, a polyester substrate, an acrylic substrate, a polyolefin substrate, a silicone substrate, a polystyrene substrate, a latex substrate, an aramid substrate, and a polyethylene substrate having a thickness of about 2-200 μm, preferably about 10 μm. In addition to a polymer substrate such as a substrate, a metal substrate of aluminum, gold, nickel, or the like can be used.

FIG. 3 is a cross-sectional view showing details around the wavelength filter plate of the first embodiment. The wavelength filter plate 108 includes a glass substrate 115, a wavelength filter film 116 composed of a dielectric multilayer film, and a low-reflection coating 117 (necessary when the refractive index difference between the glass substrate 115 and the core layer 113 is 0.1 or more). Consists of In order to realize this embodiment, it is necessary to form a groove having a very high selectivity. However, it is necessary to form a dielectric material such as quartz, polymer (polyimide, polymethyl methacrylate, epoxy, silicone, etc.) or LiNbO _3. The waveguide can be realized by using a reactive ion etching technology, an ion beam processing technology, a laser processing technology, or the like.

  The operation of the first embodiment will be described. Light incident on the input waveguide 102 propagates through the input waveguide 102 and is coupled to the slab waveguide 104. Since light is not confined in the slab waveguide 104 in a direction parallel to the substrate surface, light propagates in the slab waveguide 104 while spreading. The shape of the curve defined by the intersection of the curved surface of the groove structure 105a and the high-reflection mirror 105b with the substrate surface is determined by conditions for collimating the light reflected from the high-reflection mirror 105b. Under geometrical optical paraxial, the focal length of the curve of curvature R is R / 2, and the distance between the junction A of the input waveguide 102 and the slab waveguide 104 and the point B on the curve indicates the curvature of the curve. If R, it is R / 2. With this arrangement, the reflected light from the high reflection mirror 105b is collimated into parallel light. The wavelength filter plate 108 (wavelength filter film 116) has a function of transmitting only a specific wavelength, and the transmitted light is collected again by the high reflection mirror 106b and coupled to the output waveguide 103. Light reflected by the wavelength filter plate 108 (wavelength filter film 116) is blocked by another groove structure 107. A light absorber is inserted into the groove structure 107 as necessary. Further, it is preferable to incline the normal direction of the side surface of the groove structure 107 with respect to the optical axis so that unnecessary stray light is not coupled to the input waveguide 102 or the output waveguide 103 at the end face of the groove structure 107. The inclination angle is preferably set to be equal to or larger than the divergence angle (half angle) of the light incident on the slab waveguide 104 from the input waveguide 102. In this configuration, since the light propagates as parallel light or a Gaussian beam having a large spot diameter in the slab waveguide 104, unnecessary excessive loss can be reduced even when the groove structure 107 or the wavelength filter plate 108 is inserted. . Light has two degrees of freedom, horizontal and vertical, with respect to the propagation direction, and the contribution of one of the degrees of freedom to the loss is zero. Therefore, by using this configuration, the loss is reduced to about half (in decibels). It is possible. Further, since the high-reflection mirror 105b is formed based on the polymer film substrate 110 and is filled with the adhesive 111 whose refractive index is matched, even if the side surface of the groove structure 105a is not sufficiently smooth, the high-reflection mirror 105b can be used. Almost no scattering loss.

  FIG. 4 is a top view showing a configuration of a waveguide type optical function element according to a second embodiment of the present invention, and FIG. 5 is a cross-sectional view showing details around the ferromagnetic material. The present waveguide type optical function device is a polarization dependent type waveguide optical isolator, and includes a ferromagnetic material 119 having a Faraday effect such as YIG (yttrium iron garnet) and other RIG (rare earth iron garnet) and a polarizing filter 120a. The polarization filters 120a and 120b have their polarization axes in a plane perpendicular to the propagation of light inclined by 45 degrees. Although a magnet for applying an external magnetic field for magnetizing the ferromagnetic material 119 is required, it is omitted from the drawing.

  The operation until the incident light to the input waveguide 102 becomes parallel light in the slab waveguide 104 by the high reflection mirror 105b is the same as that of the first embodiment. Before the light enters the polarizing filter 120a, light is incident from the slab waveguide 104 into the adhesive 111 whose refractive index has been matched. The two polarization components orthogonal to the propagation direction of the light are coupled to the TE mode and the TM mode of the light propagating through the waveguide, respectively, with a very good approximation. For example, if the light incident on the input waveguide 102 propagates in the TE mode and the polarization transmission axis of the polarization filter 120a is fixed in a direction parallel to the waveguide substrate 101, the polarization axis of the light incident on the polarization filter 120a Is parallel to the waveguide substrate 101 and propagates almost through the polarizing filter 120a. If an external magnetic field is applied to the ferromagnetic material 119 in parallel to the light propagation direction, the polarization plane of the light transmitted through the ferromagnetic material 119 is rotated by 45 degrees, and when the light is coupled to the waveguide again, the TE mode and the TM mode are used. Are induced in approximately equal proportions. When the light enters the polarization filter 120b, the polarization state transmitted through the ferromagnetic material 119 is reproduced. However, since the polarization transmission axis of the polarization filter 120b is inclined by 45 degrees with respect to the polarization filter 120a, the light is transmitted through the polarization filter 120b. Is transmitted as a minimum, and is coupled back to the waveguide. Thereafter, the light is condensed by the high reflection mirror 106b and is coupled to the output waveguide 103. The return light reflected from the output waveguide 103 transmits through the polarization filter 120b, but the polarization plane is further rotated by 45 degrees in the same direction by the ferromagnetic material 119, so that the polarization axis when entering the polarization filter 120a is guided. It becomes perpendicular to the waveguide substrate 101, and the loss in the polarizing filter 120a becomes maximum. In this manner, this configuration functions as a waveguide-type optical isolator having polarization dependence.

  The advantages of the waveguide type isolator are that it is easier to reduce the size than a configuration in which a lens, a polarizing plate, and a magnetic body are arranged in a three-dimensional space, and that it can be integrated with other optical circuits. In the present embodiment, a wide beam (having a large spot diameter) is formed using a reflection structure formed in the waveguide, and the beam is propagated through the slab waveguide, and each optical element is arranged therebetween. Therefore, a waveguide type isolator in which the loss is almost halved as compared with the related art can be configured.

  FIG. 6 is a top view showing the configuration of the waveguide-type optical functional device according to the third embodiment of the present invention. The difference between this embodiment and the second embodiment is that a ferromagnetic material 119 having a Faraday effect such as YIG and other RIGs is divided into a plurality of thin ferromagnetic materials 119. Since the rotation angle of the polarization plane by the Faraday element is proportional to its thickness, it is clear that the same operation is performed even when k ferromagnetic bodies 119 having a thickness of 1 / k (k is a natural number) are used. However, the loss due to the groove in the presence of the groove structure is not proportional to the thickness of the groove but increases exponentially.

  FIG. 7 is a graph showing the effect of reducing loss by dividing the ferromagnetic material. Here, the margin of the groove width and the Fresnel reflection loss on the surface of the ferromagnetic material 119 are ignored. In this calculation, it is assumed that the total thickness L of the ferromagnetic material 119 is 200 μm. It can be confirmed that the loss decreases as the number k of divisions increases. This technique can be applied to the embodiments described below.

  FIG. 8 is a top view showing a configuration of a waveguide-type optical function device according to a fourth embodiment of the present invention, and FIG. 9 is a cross-sectional view showing details around the ferromagnetic material. The difference between this embodiment and the second embodiment is that the ferromagnetic material 121 having the Faraday effect such as YIG and other RIGs has a cylindrical shape. Generally, the ferromagnetic material 121 has a higher refractive index than quartz or a polymer waveguide material and an adhesive matching the material, and thus functions as a cylindrical lens by being formed in a cylindrical shape. Instead of a cylindrical shape, it may be processed into a cylindrical lens having a plano-convex or biconvex shape, but here, a cylindrical shape that can be easily processed and fixed is used. In a single-mode waveguide matched to an optical fiber, since the refractive index difference ratio between the core and the clad is small, the aberration of the lens does not significantly affect the connection loss. Another concave groove or a V-shaped groove may be formed at the bottom of the groove so that the ferromagnetic body 121 can be easily fixed at a fixed position. In this configuration, since the diffused light is converged by the ferromagnetic material 121, the loss due to the insertion of the ferromagnetic material 121 can be made substantially zero.

  FIG. 10 is a top view showing the configuration of the waveguide-type optical functional device according to the fifth embodiment of the present invention. The difference between this embodiment and the second embodiment is that the input waveguide 122 and the output waveguide 123 are a plurality of waveguides. It goes without saying that the present invention is applicable to other embodiments. In this configuration, a plurality of optical isolators can be integrated in a small size by performing a plurality of inputs and outputs. It is practically impossible to array optical isolators that are not waveguide-type because the minimum spacing between the input and output optical fiber arrays is 125 μm, usually 250 μm, and large numbers of inputs and outputs require large optical components. It is. That is, in order to couple the fiber arrays with a single set of lenses with high efficiency, it is necessary to make the length from one end of the array to about 1/20 of the lens diameter, so a large lens is required. . In addition, when attaching a lens to each fiber, the diameter of each lens needs to be about 2-3 mm, and a large fiber array is required to widen the fiber interval.

  FIG. 11 is a top view showing the configuration of the waveguide type optical functional device according to the sixth embodiment of the present invention. The present waveguide type optical functional element is a polarization independent waveguide optical isolator, and includes ferromagnetic materials 119a and 119b having a Faraday effect such as YIG and other RIGs, half-wave plates 124a and 124b, polarization separation. Mirror plates 125a and 125b and high reflection mirrors 126a and 126b are provided. In this configuration, the polarization separation mirror plate 125a separates the orthogonal polarization components of the incident light, that is, the TE and TM waves in the waveguide. The TE wave is transmitted, and the polarization plane is rotated 45 degrees to the right with respect to the traveling direction by the half-wave plate 124a. Next, the plane of polarization is further rotated to the right by 45 degrees by the ferromagnetic material 119a, converted into a TM wave and propagated. The light is reflected by the high reflection mirror 126a and is reflected by the polarization separation mirror plate 125b because it is a TM wave. Similarly, the TM wave propagating through the input waveguide 102 is reflected by the polarization separating mirror plate 125a, reflected by the high reflection mirror 126b, rotated by 45 degrees by the half-wave plate 124b, and further rotated by the ferromagnetic material 119b. The polarization plane is rotated 45 degrees to the right, converted into a TE wave, transmitted through the polarization separation mirror plate 125b, and combined with light that has traveled another path. The reflected return light from the output waveguide 103 side is separated by the polarization separating mirror plate 125b and transmitted through the ferromagnetic materials 119a and 119b and the half-wave plates 124a and 124b, but the rotation of the polarization plane is canceled. Therefore, the light is reflected and transmitted by the polarization separating mirror plate 125a, and is not coupled to the input waveguide 102. That is, it functions as a polarization independent waveguide optical isolator.

  FIG. 12 is a top view showing a configuration of a waveguide-type optical functional device according to a seventh embodiment of the present invention, and FIG. 13 is a sectional view thereof. The difference between this embodiment and the fourth embodiment is that the ferromagnetic material 127 having the Faraday effect, such as YIG and other RIGs, has two spherical shapes. Needless to say, a shape having a curved surface having rotational symmetry with respect to the optical axis such as a hemisphere may be used instead of the spherical shape. Polishing into a sphere facilitates the configuration because a high-precision processing technology such as a bearing can be applied. Further, it is preferable to provide a V-shaped or concave groove for fixing.

  FIG. 14 is a top view showing the configuration of the waveguide type optical function element according to the eighth embodiment of the present invention, and FIG. 15 is a sectional view thereof. In the present embodiment, the ferromagnetic material 127 processed into a shape having a curved surface having rotational symmetry such as a sphere has a lens function with respect to two axes parallel and perpendicular to the waveguide substrate 101. It is also possible to insert between two single mode optical waveguides 128. In this configuration, if the positioning accuracy is increased, the ferromagnetic material 127 can be easily inserted into the optical circuit.

  FIG. 16 is a top view showing the configuration of the waveguide-type optical functional device according to the ninth embodiment of the present invention. The structure described in this embodiment is a structure for increasing the coupling efficiency of the optical coupling circuit using the reflection structure. According to the conventional geometric optical approximation, it is considered that the configuration using an elliptical mirror in which the entrance coupling point and the exit coupling point are the focal points of the ellipse is the best. However, a more accurate imaging condition is that the light emitted from the first waveguide has a beam waist at the emission end in the plane of the slab waveguide, and the beam spot radius is equal to the mode field radius at the coupling end. It can be obtained assuming that the beam is a dimensional Gaussian beam. The directional component perpendicular to the slab waveguide plane always satisfies the single mode condition, and the mode field diameter does not change. Therefore, the coupling efficiency is 100% and need not be considered. The fact that the mirror having the radius of curvature R is a paraxial approximation and an imaging element with a focal length f = R / 2 is used, including the case of an elliptical mirror.

However,
w1: mode field radius at the first coupling end A w2: mode field radius at the beam waist of the one-dimensional Gaussian beam in the slab waveguide after mirror reflection L1: point B where the reflection structure and the optical axis intersect with the first coupling end A L2: distance between the beam waist position of the one-dimensional Gaussian beam in the slab waveguide after mirror reflection and point B R: curvature near point B neff: effective refractive index of a portion where light propagates LW: It is the wavelength of light. The coupling efficiency of the two Gaussian beams is maximized when the beam waist position and the beam spot radius match. That is, it has been found that the maximum coupling efficiency is obtained when the second coupling end C is arranged at a distance L2 from the point B and the mode field radius of the second waveguide is equal to w2.

  FIG. 17 is a graph showing the relationship between the radius of curvature of the reflection structure and the coupling efficiency. The results of calculating the coupling efficiency in the case of the configuration based on the conventional geometric optical approximation and the case of the configuration according to the present embodiment are shown. The assumptions for the calculation were that w1 = 5 μm, the distance between the input and output waveguides was 500 μm, neff = 1.534, LW = 1.55 μm, and the input side and output side were symmetrical. As is clear from the figure, when the radius of curvature of the reflecting structure is reduced, the coupling efficiency decreases from around R / 2 = 200 μm in the geometrical optics approximation, whereas in the present embodiment, R / 2 = It can be seen that the coupling efficiency does not decrease to around 80 μm. In this embodiment, when R / 2 = 60 to 200 μm, a coupling efficiency superior to that of the related art can be realized.

  FIG. 18 is a top view showing the configuration of the waveguide type optical function element according to the tenth embodiment of the present invention. This embodiment constitutes an interference measuring device 139 as a whole, and includes a waveguide substrate 101, an input waveguide 102, an output waveguide 103, a directional coupler or a multi-mode interference coupler 131, waveguides 132 and 133, It includes a delay control waveguide 134, a reflection structure 135, a lens 136, a semiconductor laser 137, and a light receiver 138. The principle of the interference measurement is as follows. The coherent light emitted from the semiconductor laser 137 is input to the input terminal P of the directional coupler 131 via the input waveguide 102, is branched to the output terminal R and the output terminal S, and is output. The branched light output from the output end R is reflected by the reflection structure 135 via the waveguide 132 and is again input to the directional coupler 131 via the waveguide 132 from the output end R. The branched light output from another output end S is connected to the outside of the waveguide, is irradiated on the observation object via the lens 136, and a part of the reflected light is connected again to the waveguide 133 via the lens 136 and is output. Return to S.

  The two return lights interfere if the optical path difference is shorter than the coherent length of the semiconductor laser 137, and the output from the input terminal Q fluctuates in units of wavelength when the optical path difference is controlled. Using this, it is possible to measure the distance to the object in units of wavelength. A delay control waveguide 134 is used for controlling the optical path difference. If the interferometer 139 is moved, the shape of the object can be measured by measuring the relative distance based on one point on the object. Of course, if the observation light is guided by an optical fiber or the like without passing through the lens 136, it is possible to measure by driving the tip of the optical fiber without moving the entire interference measuring device 139. Needless to say. Alternatively, the object may be driven on a fine movement stage.

  Further, if the oscillation wavelength of the semiconductor laser 137 is controlled, accurate measurement can be performed by measuring a plurality of different wavelengths. In addition, since there are a plurality of scales, it is also effective for measuring a large object shape having the least common multiple of the wavelength.

  Further, the present invention can be applied to interferometric measurement using incoherent light (coherent length is several microns to several tens of microns) instead of coherent light. In this case, utilizing the fact that the coherence length is very short, the reflected light from the material interface is detected to measure the layer structure, etc., so that the optical path length from the output end R to the reflective structure 135 and the output end S to the object It is necessary to make the optical path lengths up to approximately the same. A super luminescent diode or the like is used as the incoherent light source.

FIG. 19 is a top view showing the configuration of the first example of the delay control waveguide. The greatest feature of this embodiment resides in the configuration of the delay control waveguide 134. The delay control waveguide 134 of the first example includes a waveguide 132, a slab waveguide 141, a mirror 105, and a delay control region 143. The delay control region 143 is, for example, a thin film heater in the case of a quartz waveguide. If it is a semiconductor waveguide, it is an electrode for current injection or electric field application, and the other electrode is provided on the back surface. In the case of a dielectric waveguide such as LiNbO ₃ , a coplanar line or strip line type electrode may be provided. In a normal waveguide, the minimum bending radius is about 5 mm. Therefore, if a serpentine waveguide as shown in this example is formed as it is, the size becomes several cm square, which is not practical. However, if the optical path is changed by forming a mirror in the waveguide as shown in this example, it is possible to connect single-mode waveguides arranged in parallel at an interval of 0.05 to 0.5 mm. Circuits can be configured in short length regions. The mirror 105 may be formed by performing dry etching so that the end surface is vertical, and depositing a metal film such as aluminum, gold, or silver on the etched end surface by vapor deposition or sputtering. For example, if the interval between the zigzag waveguides is 0.1 mm and the length of the linear portion of the waveguide is 1 mm, a waveguide having a total length of 10 mm can be arranged in a region of about 1 mm × 1 mm.

FIG. 20 is a top view showing the configuration of the second example of the delay control waveguide. The delay control waveguide 134 of the second example is a waveguide in which a waveguide 132 is formed in a spiral shape, and a slab waveguide 141 and a mirror 142 are used to arrange a zigzag waveguide in a portion where the curvature at the center is reduced. The delay control waveguide 134 can be formed without wasting area without unnecessarily increasing the number of mirrors 142. For example, if the core diameter is 0.01 mm and the waveguide interval is 0.05 mm, a delay waveguide of about 5 m can be formed in a region having a radius of 1 cm. If the effective refractive index of the waveguide is 1.5, its temperature dependency is 5 × 10 ⁻⁵ [1 / ° C.], and the temperature control is 20 ° C., the maximum delay control amount reaches 5 mm in one way. That is, when used in an interference measuring device 139 as shown in FIG. 18, the surface unevenness up to a step of about 10 mm can be measured. Of course, if a delay waveguide is formed in the middle of the waveguide 133, an observation object at a close position can be measured.

  FIG. 21 is a top view showing the configuration of the third example of the delay control waveguide. The delay control waveguide 134 of the third example is a large slab waveguide 141 as a whole, a plurality of mirrors 134 are provided in the slab waveguide 141, and a region of an optical path reciprocating between the mirrors 134 is provided. The single-mode waveguide 132 is not disposed here as the delay control region 143. Since the loss in connection to the single mode waveguide is eliminated, the loss can be reduced.

  FIG. 22 and FIG. 23 are a top view and a partial cross-sectional view showing the configuration of the fourth example of the delay control waveguide. The delay control waveguide 134 of the fourth example is configured by a low-loss, low-curvature bending structure that does not use a mirror and a meandering waveguide that uses the bending structure. The waveguide 132 is made to have low loss by being sandwiched between groove structures 145 having a concave-convex relationship with each other in a bending structure portion having a small curvature. FIG. 23 is a sectional view taken along line A-A ′ of FIG. As described above, the waveguide core 146 and the waveguide clad 147 are sandwiched from both sides by the groove structure 145 on the waveguide substrate 101. A mirror may be formed by depositing a metal film on the side surface of the groove structure 145. In this configuration, a groove structure is provided only around the bent portion to enhance light confinement in the waveguide and reduce bending loss.

  24 and 25 are a top view and a partially enlarged view showing a configuration of a fifth example of the delay control waveguide. The delay control waveguide 134 of the fifth example is constituted by a low-loss, small-bending structure that does not use another mirror and a meandering waveguide that uses the bending structure. The waveguide 132 is made to have a low loss by being sandwiched between the small holes 148 having a concave-convex relationship with each other in a bending structure portion having a small curvature. FIG. 25 is an enlarged view of a portion of a region B in FIG. As described above, by providing many small holes 148 (cylindrical) having a smaller size than the wavelength around the waveguide core 146, light confinement in the waveguide 132 is strengthened and bending loss is reduced.

  FIG. 26 is a top view showing the configuration of the waveguide type optical function element according to the eleventh embodiment of the present invention. The interferometer 139 according to the present embodiment includes a semiconductor laser 150a, 150b, a photodetector 151a, 151b, and a wavelength multiplexer / demultiplexer 152 that multiplexes light of different wavelengths and demultiplexes light of different wavelengths. Is further provided. Since the oscillation wavelengths of the semiconductor laser 150a and the semiconductor laser 150b are slightly different, accurate measurement can be performed by measuring a plurality of different wavelengths. In addition, since there are a plurality of scales, it is also effective in measuring a large object shape having the least common multiple of the wavelength.

  FIG. 27 is a top view showing the configuration of the waveguide optical function device according to the twelfth embodiment of the present invention. The interference measuring device 139 of the present embodiment separates the light from the output end R of the directional coupler or the multi-mode interference coupler 131 into different wavelengths by the wavelength multiplexer / demultiplexer 152, and delay-controls each delay. It is controlled by the waveguide 134.

  FIG. 28 is a top view showing the configuration of the waveguide type optical function element according to the thirteenth embodiment of the present invention. The interferometer 139 of the present embodiment includes two directional couplers 131, and controls respective delays for different wavelengths by the delay control waveguide 134.

  In the twelfth and thirteenth embodiments, it is possible to separately control the delay time of light from different light sources. Although the device configuration becomes complicated, the accuracy of the measurement can be improved.

FIG. 29 is a top view showing the configuration of the waveguide type optical function element according to the fourteenth embodiment of the present invention. This embodiment constitutes a Mach-Zehnder interference type optical switch, and includes an input waveguide 153, a 1: 2 optical branch circuit 154, waveguides 155, 156, delay control waveguides 157a, 157b, and 2: 1 optical coupling. A circuit 158 and an output waveguide 159 are provided. The Mach-Zehnder interference type optical switch of the present embodiment can mount the very long delay control waveguides 157a and 157b compactly on the waveguide. There are such advantages. (1) When a switch for a low-speed signal (bit rate <about 1 Gbit / s) is configured by a refractive index control method using a thermal effect, the delay time difference between the delay control waveguide 157a and the delay control waveguide 157b is set to 5 times the signal bit width. %, The temperature of the entire switch can be controlled to perform switching. For example, assuming that the delay time difference between the delay control waveguides 157a and 157b is 0.5 ns (about 1 cm in terms of distance in the case of a silica-based waveguide), the temperature dependence of the equalized refractive index is 5 × 10 ^{With -5} [1 / ° C.], switching is possible by controlling the temperature once. Since a switch operation can be performed by controlling the entire temperature without providing a heater electrode on the chip, low-cost switching can be performed. (2) In a switch for high-speed signal or a switch for high-speed switching, the optical path length difference between the delay control waveguide 157a and the delay control waveguide 157b is set to zero or at most several wavelengths. If the optical path length of the delay control waveguide 157a and the delay control waveguide 157b is set to about 5000λ in the related art, a length of about 5mm in a conventional straight line is required. This makes it possible to reduce the size of the switch. Further, since the length of the control electrode is shortened, it is not necessary to match the phase of the high-frequency electric field applied to the electrode and the phase of the propagating light, and the switch configuration is simplified. Alternatively, if the optical path lengths of the delay control waveguides 157a and 157b are set to about 50,000λ (10 times), the applied voltage can be reduced to 1/10.

  FIG. 30 is a top view showing the configuration of the waveguide type optical functional device according to the fifteenth embodiment of the present invention. The Mach-Zehnder interference optical switch according to the present embodiment includes an input waveguide 153, a 2: 2 optical coupling circuit 160, delay control waveguides 157a and 157b, and output waveguides 159a and 159b. In this embodiment mode, a switch is used to switch whether to output the signal to the output waveguide 159a or the output waveguide 159b instead of turning the signal on and off.

  FIG. 31 is a top view showing the configuration of the waveguide type optical function element according to the sixteenth embodiment of the present invention. The Mach-Zehnder interference optical switch according to the present embodiment includes an input waveguide 153, a 2: 2 optical coupling circuit 160, waveguides 155 and 156, delay control waveguides 157a and 157b, a reflection structure 161, and an output waveguide 159c. Is provided. The present embodiment is a switch for switching output to either the input waveguide 153 or the output waveguide 159c. In this configuration, since one of the switched outputs is output from the input waveguide 153, it is necessary to connect an optical circulator before the input waveguide 153. This embodiment is a configuration in which the configuration of the fifteenth embodiment (see FIG. 30) is folded back by the reflection structure 161. Since the light propagates twice through the delay control waveguides 157a and 157b, the same effect can be obtained with a half optical path length, which is effective for miniaturization of the device.

  FIG. 32 is a top view showing the configuration of the waveguide optical function element according to the seventeenth embodiment of the present invention. The interferometer 139 of the present embodiment has a configuration in which the interferometer is extended one-dimensionally. Light incident from the semiconductor laser 150 is branched by the 1: 2 optical branch circuit 165, one of which is guided to the delay control waveguide 162a having a variable delay function, and the other is guided to the delay waveguide 162b. A variable function may be added to the delay waveguide 162b according to the application. The light emitted from the delay control waveguide 162a and the light emitted from the delay waveguide 162b spread in the slab waveguide 104, and are converted into parallel light by the reflection structures 105 and 106. Delay control waveguide 162a-reflection structure 105-semi-reflection mirror 163-observation object-semi-reflection mirror 163-light propagating through photodetector array 164, and delay waveguide 162b-reflection structure 106-semi-reflection mirror 163-propagation through photodetector array 164 The light intensity of the interference light is observed by the light receiver array 164. At this time, for example, the delay control waveguide 162a and the delay waveguide 162b are arranged so that light propagating with the reflection structure 105-the semi-transparent mirror 163-reflection structure 106 does not enter the delay waveguide 162b. In the case of the present embodiment, measurement can be performed at each point in a one-dimensional section by the photodetector array 164 in one scan in which the delay amount of the delay control waveguide 162a having a variable delay function is changed. Higher speed is possible.

  Note that the present invention is not limited to the above embodiment.

FIG. 1 is a top view illustrating a configuration of a waveguide type optical function element according to a first embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating details around a high reflection mirror according to the first embodiment. It is sectional drawing which shows the detail around the wavelength filter board of 1st Embodiment. It is a top view showing the composition of the waveguide type optical functional element by a 2nd embodiment of the present invention. FIG. 9 is a cross-sectional view showing details around a ferromagnetic material of a waveguide type optical function element according to a second embodiment of the present invention. It is a top view showing the composition of the waveguide type optical functional element by a 3rd embodiment of the present invention. 5 is a graph showing the effect of reducing loss by dividing a ferromagnetic material. It is a top view showing the composition of the waveguide type optical functional element by a 4th embodiment of the present invention. It is sectional drawing which shows the detail around a ferromagnetic body of the waveguide type optical function element by 4th Embodiment of this invention. It is a top view showing the composition of the waveguide type optical functional element by a 5th embodiment of the present invention. It is a top view showing the composition of the waveguide type optical function element by a 6th embodiment of the present invention. It is a top view showing the composition of the waveguide type optical functional element by a 7th embodiment of the present invention. It is a sectional view showing the composition of the waveguide type optical function element by a 7th embodiment of the present invention. It is a top view showing the composition of the waveguide type optical function element by an 8th embodiment of the present invention. It is a sectional view showing the composition of the waveguide type optical function element by an 8th embodiment of the present invention. It is a top view showing the composition of the waveguide type optical function element by a 9th embodiment of the present invention. 6 is a graph showing the relationship between the radius of curvature of the reflection structure and the coupling efficiency. It is a top view showing the composition of the waveguide type optical functional element by a 10th embodiment of the present invention. FIG. 3 is a top view illustrating a configuration of a first example of the delay control waveguide. FIG. 9 is a top view illustrating a configuration of a second example of the delay control waveguide. FIG. 11 is a top view illustrating a configuration of a third example of the delay control waveguide. FIG. 14 is a top view illustrating a configuration of a fourth example of the delay control waveguide. FIG. 14 is a partial cross-sectional view illustrating a configuration of a fourth example of the delay control waveguide. FIG. 14 is a top view illustrating a configuration of a fifth example of the delay control waveguide. FIG. 14 is a partially enlarged view showing a configuration of a fifth example of the delay control waveguide. It is a top view which shows the structure of the waveguide type optical function element by 11th Embodiment of this invention. It is a top view showing the composition of the waveguide type optical function element by a 12th embodiment of the present invention. It is a top view showing the composition of the waveguide type optical function element by a 13th embodiment of the present invention. It is a top view showing the composition of the waveguide type optical functional element by a 14th embodiment of the present invention. It is a top view showing the composition of the waveguide type optical function element by a 15th embodiment of the present invention. FIG. 33 is a top view illustrating a configuration of a waveguide optical function element according to a sixteenth embodiment of the present invention. It is a top view showing the structure of the waveguide type optical function element according to a seventeenth embodiment of the present invention. FIG. 11 is a cross-sectional view illustrating a configuration of a conventional waveguide optical function element. It is a top view which shows the structure of another conventional waveguide type optical function element. FIG. 11 is a top view illustrating a configuration of a conventional interference measurement optical system. It is a top view which shows the structure of the Mach-Zehnder interference type optical switch comprised from the conventional optical waveguide.

Explanation of reference numerals

Reference Signs List 101 waveguide substrate 102 input waveguide 103 output waveguide 104 slab waveguide 105, 134 mirror 105a, 107 groove structure 105b, 106b, 126 high reflection mirror 108 wavelength filter plate 109 high reflection mirror film 110 polymer film substrate 111 adhesive 112 , 202 Upper cladding layer 113, 203 Core layer 114, 204 Lower cladding layer 115 Glass substrate 116 Wavelength filter film 117 Low reflection coating 118 Pressing minute object 119, 121 Ferromagnetic material 120 Polarizing filter 122 Input waveguide 123 Output waveguide 124波長 wavelength plate 125 polarization separating mirror plate 127 ferromagnetic material 128 single mode optical waveguide 131 directional coupler or multi-mode interference coupler 132, 133 waveguide 134 delay control waveguide 135 reflection Structure 136 Lens 137 Semiconductor laser 138 Light receiver 139 Interferometer 141 Slab waveguide 142 Mirror 143 Delay control region 145 Groove structure 146 Waveguide core 147 Waveguide cladding 148 Hole 150a, 150b Semiconductor laser 151a Light receiver 152 Wavelength demultiplexing Device 153 Input waveguide 154 1: 2 optical branch circuit 155,156 Waveguide 157a, 157b Delay control waveguide 158 2: 1 Optical coupling circuit 159, 159a, 159b, 159c Output waveguide 160 2: 2 Optical coupling circuit 161 Reflection Structure 162a Delay control waveguide 162b Delay waveguide 163 Semi-transparent mirror 164 Receiver array 165 1: 2 optical branch circuit 201 Waveguide substrate 205 Optical element 206 Refractive index matching transparent adhesive 207 Single mode waveguide 208 Groove structure 209 Metallic coating 301 Coherent illumination light 302 Half mirror 303 Movable mirror 304 Interference pattern observation surface 305 Input waveguide 306 1: 2 optical branching circuit 307 Refractive index controller 308 Waveguide 309 2: 1 optical coupling circuit 310 Output waveguide

Claims (22)

A substrate on which the optical waveguide is held;
A curved groove structure formed on the substrate and having a curved surface having a normal line in the optical waveguide surface as a side surface. A plane groove structure formed on the substrate, and having a side surface on a plane whose normal is in the plane of the optical waveguide;
2. The optical waveguide device according to claim 1, further comprising an optical element inserted into the curved groove structure or the planar groove structure. An input waveguide into which input light is incident;
A slab waveguide into which light from the input waveguide is incident,
A first curved groove structure provided in the slab waveguide;
First to n-th (n ≧ 1) planar groove structures provided in the slab waveguide and receiving light from the first curved groove structure;
A second curved groove structure provided in the slab waveguide, and receiving light from the i-th (i is any one of 1 ≦ i ≦ n) planar groove structure;
3. The waveguide-type optical functional device according to claim 1, further comprising: an output waveguide from which light from the second curved groove structure enters and emits output light.   4. The light guide according to claim 1, wherein the optical element inserted into the curved groove structure is a dielectric film, a metal film, or a semiconductor film formed on a flexible film. Waveguide type optical functional element.   5. The waveguide type optical functional device according to claim 4, further comprising a substrate coated with a dielectric multilayer film inserted in at least one of said planar groove structures.   5. The optical waveguide device according to claim 4, further comprising a flat ferromagnetic material inserted into at least one of the planar groove structures.   5. The optical waveguide device according to claim 4, further comprising a columnar or cylindrical lens-shaped ferromagnetic material inserted into at least one of the planar groove structures.   5. The optical waveguide device according to claim 4, further comprising a ferromagnetic material having a spherical, hemispherical, or rotationally symmetrical shape inserted into at least one of the planar groove structures.   9. The optical waveguide device according to claim 6, further comprising a polarizing filter plate inserted into at least one of the planar groove structures.   9. The optical waveguide device according to claim 6, further comprising a polarization splitting mirror plate and a half-wave plate inserted into at least one of the planar groove structures.   The optical waveguide device according to any one of claims 4 to 10, wherein the input waveguide and the output waveguide comprise a plurality of optical waveguides. A substrate on which the optical waveguide is held;
A first optical waveguide and a second optical waveguide formed on the substrate;
A reflection structure formed on the substrate, wherein the first coupling end of the first optical waveguide and the second coupling end of the second optical waveguide are arranged at positions in an image-forming relationship with each other and coupled,
However,
w1: mode field radius at the first coupling end A w2: mode field radius at the beam waist of the one-dimensional Gaussian beam in the slab waveguide after mirror reflection L1: point B where the reflection structure and the optical axis intersect with the first coupling end A L2: distance between the beam waist position of the one-dimensional Gaussian beam in the slab waveguide after mirror reflection and point B R: curvature near point B neff: effective refractive index of a portion where light propagates LW: A waveguide-type optical functional element, wherein the second coupling end C is located at a distance L2 from the point B, and the mode field radius of the second waveguide is equal to w2 when the wavelength of light is used. A substrate on which the optical waveguide is held;
A plurality of curved groove structures formed on the substrate, the normal of which is a curved surface lying in the optical waveguide surface;
A waveguide-type optical functional element, comprising: a plurality of optical paths in the substrate, the optical paths being changed by the curved groove structure; and a delay control region for controlling a delay amount of the optical path.   14. The optical waveguide device according to claim 13, wherein the curved groove structure is two curved groove structures having an uneven relationship with each other across the optical waveguide core. The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
A 2: 2 optical coupling circuit having a first output terminal connected to an input terminal of the delay control waveguide;
A reflection structure connected to an output end of the delay control waveguide;
An output waveguide connecting a second output end of the 2: 2 optical coupling circuit to a substrate end;
An input waveguide for connecting an input end of the 2: 2 optical coupling circuit to a substrate end;
A waveguide type optical functional element, comprising: The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
A 2: 2 optical coupling circuit having a first output terminal connected to an input terminal of the delay control waveguide;
A reflection structure connected to an output end of the delay control waveguide;
An output waveguide connecting a second output end of the 2: 2 optical coupling circuit to a substrate end;
First and second wavelength multiplexer / demultiplexers having output terminals connected to first and second input terminals of the 2: 2 optical coupling circuit, respectively;
A plurality of input waveguides respectively connecting a plurality of input ends of the first and second wavelength multiplexer / demultiplexers to a substrate end. The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
A first wavelength multiplexer / demultiplexer having an output terminal connected to an input terminal of each of the plurality of delay control waveguides;
Reflection structures respectively connected to the output ends of the delay control waveguides,
A 2: 2 optical coupling circuit having a first output terminal connected to an input terminal of the first wavelength multiplexer / demultiplexer;
An output waveguide connecting a second output end of the 2: 2 optical coupling circuit to a substrate end;
Second and third wavelength multiplexer / demultiplexers having output terminals connected to the first and second input terminals of the 2: 2 optical coupling circuit, respectively;
An input waveguide for connecting a plurality of input ends of the second and third wavelength multiplexer / demultiplexers to substrate ends, respectively. The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
Two 2: 2 optical coupling circuits each having a first output terminal connected to an input terminal of the two delay control waveguides;
Reflection structures respectively connected to output ends of the two delay control waveguides,
A wavelength multiplexer / demultiplexer having first and second input terminals connected to a second output terminal of the 2: 2 optical coupling circuit, respectively;
An output waveguide that connects an output end of the wavelength multiplexer / demultiplexer to a substrate end;
An input waveguide for connecting an input end of the 2: 2 optical coupling circuit to an end of the substrate. The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
A 1: 2 optical branching circuit having first and second output terminals connected to the input terminals of the two delay control waveguides;
An input waveguide connecting an input end of the 1: 2 optical branch circuit to a substrate end;
A 2: 1 optical coupling circuit having first and second input terminals connected to output terminals of the two delay control waveguides,
An output waveguide for connecting an output end of the 2: 1 optical coupling circuit to a substrate end. The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
A first 2: 2 optical coupling circuit having first and second output terminals connected to the input terminals of the two delay control waveguides;
An input waveguide connecting an input end of the first 2: 2 optical coupling circuit to a substrate end;
A second 2: 2 optical coupling circuit having first and second input terminals connected to output terminals of the two delay control waveguides,
An output waveguide for connecting an output end of the second 2: 2 optical coupling circuit to a substrate end. The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
A 2: 2 optical coupling circuit having first and second output terminals connected to input terminals of the two delay control waveguides,
An input waveguide for connecting an input end of the 2: 2 optical coupling circuit to a substrate end;
A reflection structure connected to output ends of the two delay control waveguides, respectively. The waveguide optical function element according to claim 13 or 14 as a delay control waveguide, further,
A 1: 2 optical branch circuit in which first and second output terminals are connected to input terminals of first and second delay waveguides, at least one of which is the delay control waveguide;
An input waveguide connecting an input end of the 1: 2 optical branch circuit to a substrate end;
First and second reflection structures respectively connected to output ends of the first and second delay waveguides and collimating light emitted from the output ends;
A part of the parallel light from the first reflection structure is reflected to the observation object, and a part of the parallel light from the second reflection structure from the opposite side is reflected to the light receiver array, and a part of the parallel light from the observation object is reflected. A semi-transparent mirror transmitting the light to the light receiving array,
A light-receiving array that receives parallel light from an observation object transmitted through the semi-transparent mirror and receives parallel light from a second reflection structure that reflects the semi-transparent mirror. Type optical function element.