Abstract: Nanowire-based photodiodes are disclosed. The photodiodes include a first optical waveguide having a tapered first end, a second optical waveguide having a tapered second end, and at least one nanowire comprising at least one semiconductor material connecting the first and second ends in a bridging configuration. Methods of making the photodiodes are also disclosed.

Abstract: A coupling for conduit tubes (16, 16?) for carrying optical fibres or optical fibre units, comprising a body which has two entries (18, 18?), both entries having associated therewith means (20, 20?) to secure the body to conduit tubes inserted into the entries, the body being further provided with a space or chamber (42) between the entries through which one or more optical fibres or optical fibre units may pass, the body having a third entry (34) arranged to enable insertion of sealing material into the space, and means, such as deformable seals (26, 26?), to maintain the sealing material within the space.

Abstract: A structure comprises an inner strip waveguide (1) and an outer rib waveguide (2) on a common substrate. The thicker inner waveguide (1) is patterned into an inner core layer (3). The thinner outer waveguide (2) is patterned into an outer core layer (4). The inner and outer waveguides are separated by a gap (5) being less than 500 nm. The structure forms an adiabatic coupler. In the method, the first (inner) waveguide (1) is patterned into the thicker inner core layer (3) by etching trenches (8). A thinner outer silicon layer (4) is attached on top of the inner-core layer (3) and the first waveguide (1) to form an outer core layer (4). The second (outer) waveguide (2) is patterned into the outer core layer (4).

Abstract: An optical fiber side coupler apparatus comprising a first optical fiber and at least one multimode (MM) optical fiber having a core, the MM optical fiber for delivering light to the first optical fiber. The MM optical fiber can comprise a first length having a first location therealong wherein the core comprises a first cross sectional area A1, a second length having a second location therealong wherein the core comprises a second cross sectional area A2 that is less than the first cross sectional area A1, and a transition section, located between the first and second locations, wherein the cross sectional area of the core of the MM optical fiber is reduced. The second length can be secured alongside a selected length of the first optical fiber so as to provide optical coupling between the MM optical fiber and the first optical fiber.

Abstract: A fiber optic apparatus formed by fusing together multiple optical fibers and stretching the fused optical fibers to form a tapered portion. The tapered portion is cleaved or cut and polished to form a facet at which an optical beam is received or transmitted.

Abstract: The invention relates to a method and a device for coupling fiber optic cables. Said device comprises at least one module, which is equipped with at least one retaining unit for retaining at least two cassettes. The invention is characterized in that: a cassette is configured with at least one coupling element; at least one strand bundle can be fixed to the module, whereby said strand bundle can be split into at least two strands comprising at least one fiber optic cable; an excess length of strand can be retained by a cassette, the fiber optic cable or cables being connected to the coupling element and the cassette together with its retained strand being detachably connected to the retaining unit.

Abstract: Input ports (103a, 103b) formed from fundamental mode waveguides are provided at one end of a multimode waveguide (104). Further, an output port (105) formed from a fundamental mode waveguide is provided at the other end of the multimode waveguide (104). The multimode waveguide (104) has a width wider than those of the input ports (103a, 103b) and the output port (105), and provides modes including multimode to the waveguide. The multimode waveguide (104) is embedded with a buried layer (200). Both of the end faces of the multimode waveguide (104) are made to be planes equivalent to a (100) plane or planes inclined from these planes. In a case of inclined planes, the planes are made to be planes inclined to a direction that the waveguide region spreads toward a stacked direction of the semiconductor layers.

Abstract: An optical fiber coupler is comprised of a fusion-elongated portion 15 in which an optical fiber 11 which is designed and fabricated for use at a wavelength in the vicinity of 1.55 ?m and an optical fiber 12 which is designed and fabricated for use at a wavelength in the vicinity of 0.98 ?m are fused and elongated. The propagation constant difference between optical fibers 11 and 12 is 10?4 rad/?m or smaller.

Abstract: The invention is directed to an optical waveguide that reduces an excess loss caused in a curved waveguide region by a deviation of the center axis of a beam propagating mode from the center axis of the optical waveguide. The optical waveguide has its part curved, and assuming that the shortest distance from a certain point of a convex edge of the curved portion to a concave edge is a waveguide width at that point, the optical waveguide has its width progressively reduced from the maximum waveguide width in the midst of the curved portion toward the opposite ends of the curved portion.

Abstract: An optical platform including optical bench, an optical or photonic coupling device and a photonic circuit. The photonic circuit includes a photonic crystal along a waveguide and/or defect. The coupling device may be a waveguide or impedance matching interconnection device. The optical bench includes a rectangular trench to seat an optical fiber and provide alignment with the photonic circuit.

Abstract: The present invention relates to a curved optical waveguide which is free of any axis-deviation structure in the middle of the waveguide and which has a sigmoidal core shape, wherein the curvature thereof at one end is zero and the curvature thereof at the other end is finite (>0) and the use of such a curved optical waveguide permits the reduction of optical loss at the connected portions to the lowest possible level even when it is applied to, for instance, an optical splitter or a directional coupler and the curved optical waveguide of the present invention can provide an optical waveguide which never requires the use of any offset.

Abstract: Microresonators, such as a microsphere resonators and planar microresonators, are optically coupled to waveguides for input and output of light. It is important that the relative positions of the microresonator and the waveguide are maintained stable, while still maintaining high cavity Q and ease of launching and extracting the optical beams. Structures are provided on a substrate that are useful for maintaining the position of the microresonator relative to the waveguide. The structures provide for vertical or horizontal coupling between the waveguide and the microresonator.

Abstract: An apparatus includes a first waveguide configured to focus an electromagnetic wave to a focal region, and a second waveguide defining an opening having an end positioned adjacent to the focal region, the second waveguide including a first metallic layer, and second and third layers positioned on opposite sides of the first metallic layer, wherein the first metallic layer has a first propagation constant larger than propagation constants of the second and third layers.

Abstract: A microstructured optical waveguide is formed to include a periodic sequence of “plugs” of optically active material within the inner cladding air tunnels. The plugs are utilized as a grating structure for generating resonant and periodic structures. The waveguide (in one embodiment, an optical fiber) is tunable by changing the spacing of the plugs (e.g., heating the structure, changing the pressure within the structure, etc.), or by modifying the initial spacing of the plugs during the formation of the microstructured optical waveguide (i.e., by modifying the “dipping frequency” of the waveguide into a reservoir of optically active material). In general, any number of different types of optically active material may be used to form the plugs, where two or more different materials may be used in the same structure, and introduced in an alternating fashion.

Abstract: An optical transmission fiber is formed to include a relatively low-index, relatively thin outer cladding layer disposed underneath the protective polymer outer coating. Stray light propagating along an inner cladding layer(s) within the fiber will be refracted into the thin outer cladding (by proper selection of refractive index values). The thin dimension of the outer cladding layer allows for the stray light to “leak” into the outer coating in a controlled, gradual manner so as to minimize heating of the coating associated with the presence of stray light. The inventive fiber may also be bent to assist in the movement of stray light into the coating.

Abstract: An optical coupler for parallel coupling from a single mode optical fiber, or fiber ribbon, into a silicon-on-insulator (SOI) waveguide for integration with silicon optoelectronic circuits. The optical coupler incorporates the advantages of the vertically tapered waveguides and prism couplers, yet offers the flexibility of planar integration. The optical coupler may be fabricated using wafer polishing technology or grayscale photolithography. The optical coupler can be packaged using epoxy bonding to form a fiber-waveguide parallel coupler or connector.

Abstract: An optical fibre coupling structure comprising an optical fibre having an elongate input surface and shaped so that the diameter of the core of the fibre reduces in one dimension away from the input while increasing in the other dimension away from the input to form respective convergent and divergent surfaces, towards an output which is more circular than the input.

Abstract: An optical device for collecting light and selectively outputting or concentrating the light. A layer has an optical index of referaction n1, and top, bottom and side surfaces defining an angel of inclination ?. A back surface spans the top, bottom and side surface. A first layer is coupled to the bottom surface of the layer and has an index of refraction n2. The first layer index n2 causes light input through the back surface of the layer to be preferentially output into the first layer. A second layer is coupled to the bottom of the first layer and selectively causes output of light into ambient. Additional layers, such as alight polarization layer, a polarization converting layer and a post LCD diffuser layer can be used to make preferential use of polarized light of diffuse light having passed through the LCD layer to enhance viewing of the output light.

Abstract: A laser handpiece is disclosed, including a shaped fiber optic tip having a side-firing output end with a double bevel-cut shape. The shaped fiber optic tip can be configured to side-fire laser energy in a direction away from a laser handpiece and toward sidewalls of a treatment or target site.

Abstract: An optical device for collecting light and selectively outputting or concentrating the light. A layer has an optical index of referaction n1, and top, bottom and side surfaces defining an angle of inclination ?. A back surface spans the top, bottom and side surface. A first layer is coupled to the bottom surface of the layer and has an index of refraction n2. The first layer index n2 causes light input through the back surface of the layer to be preferentially output into the first layer. A second layer is coupled to the bottom of the first layer and selectively causes output of light into ambient. Additional layers, such, as alight polarization layer, a polarization converting layer and a post LCD diffuser layer can be used to make preferential use of polarized light of diffuse light having passed through the LCD layer to enhance viewing of the output light.

Abstract: Systems and methods for steering at least one of two or more optical input beams and forming a combined optical output beam are disclosed. A system has a waveguide, one or more phase controlling devices and one or more beam steering devices. The waveguide is configured to combine the optical input beams. The one or more phase controlling devices are configured to control a phase of at least one of the optical input beams. The system can form a coherently combined optical output beam. The one or more beam steering devices are configured to laterally steer, angularly steer, or laterally and angularly steer at least one of the optical input beams. The waveguide, in conjunction with the one or more beam steering devices, is configured to form the combined optical output beam that is angularly steered, laterally steered, or angularly and laterally steered.

Abstract: An optical coupler, the optical coupler being usable with a first optical fibre and a second optical fibre. The second optical fibre defines a second fibre coupling section and a second fibre transmitting section extending from the second fibre coupling section. The second fibre coupling section defines a radially outwardmost peripheral surface, the radially outwardmost peripheral surface defining a peripheral surface coupling portion. The optical coupler includes a coupler first end section and a substantially opposed coupler second end section, the coupler first end section defining a first coupling surface. The optical coupler defines a second coupling surface extending along the coupler first and second end sections. The first coupling surface is optically couplable with the first optical fibre and the second coupling surface is positionable so as to extend substantially parallel to the peripheral surface coupling portion and to be optically coupled with the peripheral surface coupling portion.

Abstract: An arrayed waveguide grating type optical multiplexer/demultiplexer circuit in which wavelength dispersion is reduced. An input wave guide (1), a first slab waveguide (2), an arrayed waveguide (3), a second slab waveguide (4) and an output waveguide (5) are connected sequentially. Furthermore, a parabola waveguide (6) is provided between the input waveguide (1) and the first slab waveguide (2), and a taper waveguide (7) is provided between the second slab waveguide (4) and the output waveguide (5). A parabola waveguide length Z0 exists in a range Za,0=Z0=Zp,0 determined by a parabola waveguide length Za,0 where the ratio of absolute amplitude between the main peak and the first side peak in the field distribution of far-field of the parabola waveguide (6) has an upper limit of 0.217, and a parabola waveguide length Zp,0 where the relative phase of the main peak and the first side peak in the field distribution of far-field has a lower limit of 3.14 radian.

Abstract: Embodiments provide single fiber bidirectional HDCP modules. A signal fiber module includes at least one laser and at least one detector and a waveguide combiner/splitter. An optical fiber is used as a cylindrical lens in order to partially collimate in the vertical axis the optical signals entering and leaving branches of a waveguide. The branches of the waveguide have lens-shape interfaces in order to at least partially collimate in the horizontal axis the beams entering and leaving the waveguide. Each branch of the waveguide tapers toward a join-section of the waveguide. At the join section, the cross-section of a laser branch is smaller than the cross-section of a detector branch. If more than one detector is present in a module, the cross-sections of the detector branches differ from each other. If more than one laser is present in a module, the cross-sections of the laser branches differ from each other.

Abstract: A method for making a high-power fused collimator, and a fused collimator made thereby, are provided. A fused collimator is provided that includes an end of a stripped end portion of an optical fiber fused to a proximal face of a silica lens. In an embodiment, a joint formed by the fiber end and the silica lens proximal face is substantially surrounded with a solder glass in a melted form. A cross-sectional area of the solder glass decreases proximally from a distal edge adjacent the lens to a proximal edge located along the fiber's stripped end portion. The solder glass is permitted to harden, forming a fused collimator. In another embodiment, a ferrule surrounds the fiber stripped end portion, and an adhesive is applied to the ferrule's proximal face to surround the fiber. The lens-ferrule joint is surrounded with solder glass, which is then surrounded with a silica sleeve.

Abstract: Waveguide structures in which light confinement strength varies along the direction of light propagation are described. The waveguides include a core adapted to propagate light along a path defined by the core and a cladding material that at least partially surrounds the core. The core and the cladding material each have a refractive index profile in the direction of light propagation. One or more of the profiles or lateral core dimensions are varied along the direction of light propagation, thereby causing the degree of light confinement to vary in the direction of light propagation. With such structures it is possible to tailor the velocity of the light propagating through the core and the confinement of the light to the core for any given core cross section. The structures may be used, for example, in mode-matching an input or output of a waveguide and in fabricating compact directional couplers.

Abstract: The multichannel waveguide device includes an array of waveguides located in a plane. Each waveguide channel has a redirecting element for redirecting a guided wave out of said plane, or vice versa. The redirecting elements are staggered in the direction of the waveguides so as to transform a one-dimensional array of in-plane waves into a two-dimensional array of out-of-plane waves, or vice versa.

Abstract: An optical waveguide module has a planar type optical waveguide having at least one core, an optical fiber for connecting with the core of the optical waveguide optically, and an optical element for connecting the core of the optical waveguide optically. The optical waveguide includes a groove for allowing an optical fiber to be inserted thereinto and aligning the optical fiber with the core to connect the optical fiber and the core optically. A first edge of the optical waveguide, which traverses the core, is tapered and an edge of the core, which is exposed in the first edge of the optical waveguide, is formed as a reflection surface. A planar type optical element is mounted as the optical element at a position that is opposite to the reflection surface to connect the planar type optical element with the core optically through the reflection surface.

Abstract: A polarization sorter having an input, an output and a slowly varying region. The input has at least one input waveguide. The input waveguide supports at least one guided TE polarized mode of mode ranking mode-i-TE, and at least one guided TM polarized mode of mode ranking mode-j-TM. The output has at least two output waveguides. At least one output waveguide supports a TE polarized mode of mode ranking mode-i-TE, and at least one waveguide supports a TM polarized mode of mode ranking mode-j-TM. The slowly varying region couples the at least one input waveguide at the input to the at least two output waveguides at the output.

Abstract: A polarization insensitive semiconductor optical amplifier (SOA) is provided. The SOA includes an active waveguide, a passive waveguide, and a taper coupler for coupling optical energy from the passive waveguide into the active waveguide, wherein the taper coupler has width W varying relative to position along a main axis z of propagation of the SOA in proportion to the minimum value of 1/CTE 01(z) 1/CTM 01(z), where CTE 01(z) represents the coefficient of energy coupling between a fundamental mode and a first order mode for the transverse electric polarization as a function of the position z, and CTM 01(z) represents the coefficient of energy coupling between a fundamental mode and a first order mode for the transverse magnetic polarization as a function of the position z.

Abstract: An electromagnetic coupler comprising: a coupling waveguide adapted for receiving input modes along an input axis, propagating coupling modes along a coupling axis, and transmitting output modes along an output axis, the output axis being not parallel to the coupling axis; and an output waveguide disposed adjacent the coupling waveguide and adapted for receiving the output modes.

Abstract: A waveguide and resonator are formed on a lower cladding of a thermo optic device, each having a formation height that is substantially equal. Thereafter, the formation height of the waveguide is attenuated. In this manner, the aspect ratio as between the waveguide and resonator in an area where the waveguide and resonator front or face one another decreases (in comparison to the prior art) thereby restoring the synchronicity between the waveguide and the grating and allowing higher bandwidth configurations to be used. The waveguide attenuation is achieved by photomasking and etching the waveguide after the resonator and waveguide are formed. In one embodiment the photomasking and etching is performed after deposition of the upper cladding. In another, it is performed before the deposition. Thermo optic devices, thermo optic packages and fiber optic systems having these waveguides are also taught.

Abstract: An integrated optical mode transformer provides a low loss interconnection between an optical fiber and an integrated optic waveguide having a spot size different from that of the fiber. The mode transformer is comprised of two waveguide layers, an upper layer and a lower layer, with the upper layer being contiguous to the lower layer. The lower layer is the integrated optic waveguide layer forming the optical circuit. The input dimensions of the composite two-waveguide structure supports a fundamental mode that accepts all of the light present on the optical fiber. The upper waveguide layer is tapered down from an input width to an output width and then terminates in such a way that at the termination substantially all of the input optical power resides in the lower waveguide layer. The two-waveguide layer structure is fabricated by deposition and planarization techniques.

Abstract: Provided is a double waveguide electroabsorption modulator, in which two spot size converters are integrated between first and second optical waveguides, thereby reducing an insertion loss between an optical fiber and an optical modulator while favorably operating even in high input optical power. Therefore, the electroabsorption modulator can stably operate in higher input optical power while reducing an optical coupling loss and an optical confinement factor (OCF).

Abstract: The invention described here is an improved fiber optic probe. The tip of the probe is made from a transparent fill material that is connected to the end of a conventional optical fiber. The optical fiber is tapered, the fill material is connected thereto, and typically extends outwardly from the fiber as though it is a continuous part of the fiber. The outer diameter of the fill material is preferably essentially the same as the optical fiber. The fill material may contain light-scattering elements that disperse light as it exits the fiber.

Abstract: An optical waveguide coupler for optically coupling an optical waveguide and an optical component having mutually different spot sizes, includes (1) a first spot size converting part, placed on the optical waveguide side, that converts a spot size with higher efficiency for an optical signal of a long wavelength band than for an optical signal of a short wavelength band, and (2) a second spot size converting part, placed on the optical component side, that converts a spot size with higher efficiency for the optical signal of the short wavelength band than for the optical signal of the long wavelength band.

Abstract: An optical waveguide device includes a plurality of optical waveguides propagating therethrough a signal beam, and a plurality of optical sub-waveguides connected to the plurality of optical waveguides respectively, applying an excessive loss to the signal beam by branching a partial beam of the signal beam. A dynamic range and a tolerance in an amount of the excessive loss is adjusted by adjusting widths of the plurality of optical sub-waveguides with respect to the plurality of optical waveguides, and the amount of the excessive loss applied to the signal beam are adjusted by adjusting an angle connecting each of the plurality of optical sub-waveguides with respect to each of the plurality of optical waveguides.

Abstract: The use of bulge-like microcavities in microcavity sensors provides advantages in alignment and reproducibility in manufacturing. Arrays of bulge-like microcavities may be used with multiple waveguides. In addition, the bulge-like microcavity may be formed with at least an outer layer made of a polymer material, and may be made entirely from polymer material. This facilitates manufacturing in that the microcavity may be molded, and may also be reproducibly molded in an array configuration.

Abstract: A device and method for multiplexing or demultiplexing M optical signals, each having a different wavelength ?m. An MMI waveguide has a length such that each optical signal that propagates into the MMI waveguide at an i:th access waveguide, where i?N, and N is greater than or equal to 2, produces N self-images inside the MMI waveguide at a respective distance Im from the access waveguides. Each of M wavelength selective reflectors is arranged near a respective distance Im, wherein the m:th reflector reflects the optical signal carried by the m:th wavelength, where 2?m?M, while being substantially transparent to all other wavelengths. Each of M phase adjustors is arranged relative to a corresponding reflector, wherein the m:th phase adjustor adjusts the phase of the self-images of the optical signal carried by the m:th wavelength to create a single self-image at a selected output access waveguide when reflected by the m:th reflector.

Abstract: A planar waveguide circuit includes a silica-based planar optical waveguide circuit having a lower cladding, a core and an upper cladding. At least one input waveguide and one output waveguide are each coupled to the optical waveguide circuit. At least one tapered waveguide section is located in the waveguide circuit, which has an upper cladding segment that tapers down to at least the core to define a tapered recess. A filler material having a negative thermo-optic coefficient fills the tapered recess so that the optical waveguide circuit has an optical characteristic with a reduced temperature dependence.

Abstract: In an embodiment, light from a single mode light source may be deflected into a low index contrast (LIC) waveguide in an opto-electronic integrated circuit (OEIC) (or “opto-electronic chip”) by a 45 degree mirror. The mirror may be formed by polishing an edge of the die at a 45 degree angle and coating the polished edge with a metal layer. Light coupled into the LIC waveguide may then be transferred from the LIC waveguide to a high index contrast (HIC) waveguide by evanescent coupling.

Abstract: An asymmetric twin waveguide (ATG) structure with an integrated amplifier and detector fabricated in a single active waveguide layer is disclosed. The structure comprises an active waveguide layer formed on a passive waveguide layer. The active and passive waveguides have different effective indices of refraction such that a first mode of light is confined primarily to the active waveguide and a second mode of light is confined primarily to the passive waveguide in the area where the waveguides overlap.

Abstract: A multiple-fiber, stretched, fused and cleaved coupler designed to act as an output window to a fiber laser array or fiber-coupled laser array, in which the stretch, length and/or position of the fibers is chosen facilitate the in-phase oscillation of the lasers in the array. The in-phase oscillation of the lasers is facilitated by making one or more of the fibers interferometrically dark. The other fibers, the interferometrically lit ones, are made to have fairly uniform intensity under the same collimated illumination.

Abstract: A 1×2 splitter design having low loss is described. The splitter has a non-adiabatic tapered waveguide (22) connected between a substantially single-mode input waveguide (20) and two output waveguides (24, 26). The non-adiabatic tapered waveguide widens in width towards the output waveguide, and merges substantially continuously with the input waveguide in a direction parallel to the optical axis of the input waveguide. This keeps radiation mode generation to a minimum which, in turn, keeps insertion loss low. In the described embodiment, the non-adiabatic taper shape is based on a perturbed cosine function. The 1×2 splitter can be cascaded with other such splitters in order to build a 1×2N splitter design.

Abstract: Illumination of objects in an optical inspection system may utilize an at least partially-coherent light source optically connected to a fiber optic bundle that is linked to a light guide comprising a single optical element. The combination of the bundle and element provides coherence-breaking effects and serves to smooth out angular and spatial non-uniformities. The end face of the light guide may be tapered such that the output end of the light guide is wider than the input end. The illumination system may be configured to illuminate an object such as a semiconductor wafer with critical, Kohler, or other illumination, and may further include a diffuser or other optical elements. The light guide and fiber bundle combination may be used alone or as part of a larger illumination system.

Abstract: A funnel-type planar lightwave circuit (PLC) optical splitter having an input optical waveguide, a slab waveguide receiving the input optical signal from the input optical waveguide, and output waveguides projecting from the slab region. The region connecting the slab waveguide to the output waveguides is characterized by a segmented taper structure. In another additional, or alternative aspect of the present invention, a cladding mode absorption region runs along either or both sides of the input optical waveguide. A funnel-type splitter with both a cladding mode absorption region and a segmented taper structure provides a “super” low loss splitter design, when considering both insertion loss and polarization dependent loss. Advantageously, the disclosed funnel-type PLC splitter does not require a quartz substrate due to its very low PDL, and a silicon substrate can be used. Silicon substrates are known to be lower cost, with a higher resistance to fracture.

Abstract: An optical apparatus comprises: a waveguide substrate; three planar optical waveguides formed on the substrate, each comprising a transmission core and cladding; a laser positioned to launch its optical output to propagate along the first waveguide; a photodetector positioned to receive an optical signal propagating along the second waveguide; and means formed on the substrate for i) transferring a first fraction of laser optical output propagating along the first waveguide to the second waveguide, and ii) transferring a second fraction of the laser optical output propagating along the first waveguide to the third waveguide. The transferring means may comprise: i) a pair of parallel spaced-apart tap core segments; ii) a branched splitter core; or iii) a lateral splitter core.

Abstract: Directional light beam generators are implemented in waveguides with tilted core structures. The waveguides have cores, cladding and jacket layers. A directional light beam with small divergent beam angle is generated after propagating through the waveguides. Divergent light beams with large beam sizes can be converted into beams with small sizes.

Abstract: The described integrated planar optical structure comprises a principal waveguide having a core and a cladding that define a first light path ad means sensitive to the light radiated into the cladding comprising at least one secondary waveguide having a core and a cladding that define a second light path. The secondary waveguide has an entry situated in the cladding of the principal waveguide at such a distance from the core of the latter as not to interfere with the propagation of the light along the first optical path and a core section that becomes greater in a first part from the entry onwards to collect the light energy radiated into the cladding. Also described are a system for monitoring the light energy emitted by a source and an optical attenuator that comprise the aforesaid optical structure.

Abstract: To solve the wavelength dependence of loss uniformity between waveguides for output. A waveguide for input for introducing an optical signal, a slab waveguide for branching off the optical signal introduced in the waveguide for input by diffraction and propagating, and a plurality of waveguides for output for outputting individually a plurality of optical signals which are branched off inside of the slab waveguide are provided. The waveguide for input is configured such that an output end thereof is connected to an incident end of the slab waveguide and has a function for converting a spot size of the optical signal on the incident end of the slab waveguide at a connection point with the slab waveguide.