Abstract: An optical switch ideally suited for use as an optical add drop multiplexer (OADM). A light beam entering the OADM through a first input fiber (402) is separated by wavelength to yield multiple light beams (902, 904). One light beam (902) is reflected by one or more of the mirrors in mirror array (908). Depending on the position of the mirrors struck by light beam (902), the beam is reflected to a first region of a retro-reflector (910) or a second region (912). When light beam (902) is reflected by the second region (912) of the retro-reflector, it again travels to the mirror array (908) and is then reflected to a wavelength combiner (914) and output on the second (“drop”) output fiber (408). While a first wavelength light beam (902) is reflected to the drop output (408), other wavelengths of light from the first input (402), for example light beam (904), are directed to the “out” optical fiber (406).

Abstract: A photonic switch for an optical communication network includes a matrix of actuator-mirror assemblies and a corresponding matrix of optical ports. A first one of the actuator-mirror assemblies directs a beam of light received from an input optical port to a reference mirror, where it is reflected to a second actuator-mirror assembly that redirects the beam to an output optical port. Each of the actuator-mirror assemblies includes a mirror-coil assembly mounted to a gimbal, with stationary magnets being positioned adjacent a corresponding one of the coils such that when current flows through the coils a force is generated that causes the mirror-coil assembly to tilt. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: A micro-optic polarization beam multiplexing system has collimating means for introducing a first pair of polarization-perpendicular input beams, collimating means for introducing a second pair of polarization-perpendicular input beams, a polarization beam combiner for combining the first pair and the second pair of input beams into a first combined light beam with wavelength &lgr;1 and a second combined light beam with wavelength &lgr;2, and a filter for multiplexing the first combined light beam and the second combined light beam into an output beam with wavelengths &lgr;1 and &lgr;2. The micro-optic system can also be used inversely for de-multiplexing an input beam with wavelength &lgr;1 and wavelength &lgr;2 into a first de-multiplexed light beam with wavelength &lgr;1 and a de-multiplexed light beam with wavelength &lgr;2, and then splitting them into two pairs of polarization-perpendicular beams.

Abstract: The present invention relates to a device for use in a fiber optic system that may be a communication system, a sensing system or other system using guided-wave optical components. Reducing the number of lenses required to couple the waveguides and the free-space paths in the device offers the dual advantages of a reduced component count and simplified alignment. In an exemplary device having a first and second waveguides, a birefringent optical system defines bi-directional, polarization-dependent free-space paths. One of the bi-directional, polarization-dependent, free-space paths couples at least the first waveguide to the second waveguide. The birefringent optical system includes at least one prism for bending one of the polarization-dependent paths in a clockwise direction and one of the polarization-dependent paths in a counterclockwise direction.

Abstract: An optical coupling system for use with multiple wavelength optical signals provides improved coupling efficiency between a free-space optical beam and a relatively thin, surface layer of an SOI structure (“SOI layer”), allowing for sufficient coupling efficiency (greater than 50%) over a predetermined wavelength range. An evanescent coupling layer, disposed between a coupling prism and an SOI layer, is particularly configured to improve the coupling efficiency. In one embodiment, the thickness of the evanescent layer is reduced below an optimum value for a single wavelength, the reduced thickness improving coupling efficiency over a predetermined wavelength range around a defined center wavelength. Alternatively, a tapered thickness evanescent coupling layer may be used to improve coupling efficiency (or a combination of reduced thickness and tapered configuration).

Abstract: According to this invention, electrodes are formed on both sides of a part of an optical waveguide formed on a substrate and a voltage is applied between the electrodes to change the refractive index at the part of the optical waveguide where the electrode is formed. Therefore, the traveling direction of light can be changed. Moreover, an optical waveguide formed on a substrate, plural electrodes formed on both sides of the optical waveguide, plural incidence units formed at one end of the substrate, and plural emission units formed at the other end are provided. A voltage applied to an arbitrary electrode of the plural electrodes is controlled to change the refractive index at the part of the optical waveguide where the voltage is applied. Light emitted from an arbitrary incidence unit and incident on a core of the substrate thus becomes incident on an arbitrary emission unit.

Abstract: A movable mirror having a mirror surface reflecting a light input from an input fiber collimator is moved in an arrow (1) direction so that the reflection frequency of the input light reflected by an optical filter can be variable. The light is reflected plural times between the mirror surface and the optical filter, directed to a fixed mirror by the mirror surface, reflected by the fixed mirror, and is connected to an output fiber collimator. By moving the movable mirror in parallel, the reflection count of the light between the optical filter and the mirror surface is variable. Therefore, the wavelength characteristic of the light is obtained as an accumulated wavelength characteristic depending on the reflection count.

Abstract: A method and apparatus for multiplexing and demultiplexing optical signals. The apparatus includes first and second optical waveguides coupled via an optical coupler. The optical coupler has a coupling waveguide and an optical switching wedge attached to a piezoelectric actuator. In operation, first and second optical signals are received by the first and second optical waveguides, respectively. If the signals are to be combined, the optical switching wedge is moved to a first position where it is optically coupled to the first optical waveguide. The first optical signal is then transmitted, via the coupling waveguide, to the second optical waveguide, where it is combined with the second optical signal. If the signals are not to be combined, the optical switching wedge is moved to a second position where it is optically uncoupled from the first optical waveguide.

Abstract: A practical realization for achieving and maintaining high-efficiency transfer of light from input and output free-space optics to a high-index waveguide of sub-micron thickness is described. The required optical elements and methods of fabricating, aligning, and assembling these elements are discussed. Maintaining high coupling efficiency reliably over realistic ranges of device operating parameters is discussed in the context of the preferred embodiments.

Abstract: A trapezoidal shaped single-crystal silicon prism is formed and permanently attached to an SOI wafer, or any structure including a silicon optical waveguide. In order to provide efficient optical coupling, the dopant species and concentration within the silicon waveguide is chosen such that the refractive index of the silicon waveguide is slightly less than that of the prism coupler (refractive index of silicon≈3.5). An intermediate evanescent coupling layer, disposed between the waveguide and the prism coupler, comprises a refractive index less than both the prism and the waveguide. In one embodiment, the evanescent coupling layer comprises a constant thickness. In an alternative embodiment, the evanescent coupling layer may be tapered to improve coupling efficiency between the prism and the waveguide. Methods of making the coupling arrangement are also disclosed.

Abstract: A wavelength router is provided that selectively directs spectral bands between an input port and a set of output ports. The router includes a free-space optical train disposed between the input port and the output ports. The free-space optical train may include air-spaced elements or may be of generally monolithic construction. The optical train includes a transmissive dispersive element, such as a transmissive diffraction grating, disposed so that light is intercepted from the input port and encounters the transmissive dispersive element at least four times before reaching any of the output ports.

Abstract: The present invention relates to an integrated optical fiber collimator with a built-in polarizing beam splitter. An embodiment of the present invention includes a housing, an optical fiber, a collimating lens system that includes at least one lens, and a polarizing beam splitter. The optical fiber terminates in the housing at an optical fiber termination. The collimating lens system is in the housing and is in optically communication with the optical fiber through the optical fiber termination. The housing mechanically supports the polarizing beam splitter. The polarizing beam splitter separates the light from the optical fiber into two substantially orthogonally polarized light beams and substantially couples two orthogonally polarized light beams to the optical fiber in conjunction with the collimating lens system.

Abstract: An optical switch (10) includes an input device (11), a reflection output device (12), a transmission output device (13), a prism (2) and a rotation device (3). The input and reflection output devices are rotatable around the prism between a first position and a second position. The prism has a reflective surface (21) to effect optical switching. When the input and reflection output devices are at a first position, an input light beam from the input device passes through the reflective surface of the prism, and is output through the transmission output device. When the input and reflection output devices are at a second position, the input light beam from the input device is incident on the reflective surface of the prism at an angle which is equal to or larger than a critical angle of the prism. The input light beam is totally reflected by the reflective surface of the prism and is output through the reflection output device.

Abstract: A wavelength multiplexing bidirectional optical transmission module includes a transparent plate having first and second reflection surfaces opposing each other, a diffraction grating formed on a part of one of the first and second reflection surfaces and photoelectric transfer elements. The diffraction grating receives a wavelength-multiplexed optical signal composed of at least two light beams of proximate wavelength bands and produces diffracted light beams one for each wavelength at different angles. The photoelectric transfer elements receive the diffracted light beams, respectively, that have been reflected and propagated between the first and second reflection surfaces.

Abstract: The invention relates to an optical device comprising an emitting source and a partly-reflective element which is adapted for receiving an emitted light beam. This element is tilted in a small angle with respect to the emitted light beam. A portion of the emitted light beam is reflected by the partly-reflective element towards a transmittive element which is arranged in close proximity to the emitting source and adapted to receive and transmit the reflect portion. The transmittive element is arranged for at least partly fixing or positioning an optical fiber, which is emitting the input light beam, and provided for transmitting the laterally offset reflected portion of the input light beam away from the input fiber.

Abstract: Various methods, systems and apparatuses in which a chromatic dispersion compensation module includes an input fiber, an output fiber, a lens, and an etalon resonator. The input fiber has a first core with a center. The output fiber has a second core with a center. The input fiber is adjacent to the output fiber. The spacing between the center of the first core and the center of the second core is affixed to less than one hundred and twenty microns. The input fiber routes an optical signal to lens. The lens routes the optical signal to the etalon resonator. The etalon resonator has reflectors with fixed reflectivity and a variable optical length to induce a wavelength-dependent delay into the optical signal. The a etalon resonator routes the optical signal to the output fiber through the lens.

Abstract: An interleaver has an input polarization beam displacer, a birefringent filter assembly in optical communication with the input polarization beam displacer, a first output polarization beam displacer in optical communication with the birefringent filter assembly and a second output polarization beam displacer optical communication with the first output polarization beam displacer. The birefringent filter assembly preferably comprises at least one birefringent filter stage, wherein each birefringent filter stage comprises a first filter polarization beam displacer, a second filter polarization beam displacer and at least one reflector configured so as to direct light from first filter polarization beam displacer to the second filter of polarization beam displacer.

Abstract: An optical coupler includes a housing, and includes first and second optical terminals and a prism disposed in the housing. One terminal is moveable with respect to the other, and the prism maintains an optical alignment between the terminals. Because it includes a prism instead of a more complex and delicate optical assembly, such an optical coupler can often be less expensive and more rugged, and can often have a higher connection density, than prior optical couplers.

Abstract: A first optical fiber, a second optical fiber, and a prism are used to turn light through 180° in a small space. The prism can be a discrete microprism or a custom prism specially made using precision molding techniques or by specially machining a section of coreless optical fiber using precision machining techniques. A precision holder or substrate can be used to facilitate molding of a prism and/or assembly of the overall apparatus.

Abstract: A wavelength router that selectively directs spectral bands between an input port and a set of output ports. The router includes a free-space optical train disposed between the input ports and said output ports, and a routing mechanism. The free-space optical train can include air-spaced elements or can be of generally monolithic construction. The optical train includes a dispersive element such as a diffraction grating, and is configured so that the light from the input port encounters the dispersive element twice before reaching any of the output ports. The routing mechanism includes one or more routing elements and cooperates with the other elements in the optical train to provide optical paths that couple desired subsets of the spectral bands to desired output ports. The routing elements are disposed to intercept the different spectral bands after they have been spatially separated by their first encounter with the dispersive element.

Abstract: An optical circulator of the present invention comprises (a) an array of ports, the array comprising at least a first port and a last port, each port is adapted to (i) inject a beam of light into said optical circulator, and (ii) remove a beam of light from said optical circulator; (b) a first reflective member adapted to receive a beam of light from a port and to reflect the beam of light to a second reflective member; (c) a second reflective member adapted to receive a beam of light from the first reflective member and to reflect the beam of light to a third reflective member; and (d) a third reflective member adapted to receive a beam of light from the second reflective member and to sequentially direct the beam to a next port of the array so as to circulate the beam of light through at least a portion of the array of ports.

Abstract: An optical sub-assembly (OSA) module for suppressing optical back-reflection and effectively guiding light from a light source to an optical waveguide is disclosed. The module comprises a light source for emitting light to said optical waveguide and at least one light transmitting element installed between said light source and said optical waveguide. The at least one light transmitting element is arranged to have a configuration for avoiding light to reflect back to the light source and to cause a light beam from said light source to point to said core of said optical waveguide. Thereby, the working distance is increased, and the assembling process of the OSA module is simplified. This new optical design scheme will greatly improve the optical characteristics of an OSA module, increase the optical transceiver propagation distance, and reduce the difficulty of OSA assembly process.

Abstract: In another aspect, the invention provides a closed loop optical circulator including a first crystal for splitting an input light signal into two components, a second crystal for deflecting the two components received from the first crystal in a direction if the two components have a first polarization, a third crystal for deflecting the two components received from the second crystal in an opposite direction if the two components have the first polarization, and a fourth crystal for joining the two components received from the third crystal.

Abstract: In a triangular-sectioned prism 11 having a first plane 11a opposite an end face of an optical fiber 12, a second plane 11b opposite a light receiving element 13 and a third plane 11c which reflects received light 21 incident thereon from the optical fiber 12 toward the second plane 11b and transmits transmission light 22 emitted from a light emitting element toward the first plane 11a, a cylindrical member 32 of a refractive index larger than that of the prism 11 is embedded in that area of the prism 11 which is opposite the end face of the optical fiber 12. The cylindrical member 32 effectively suppresses the leakage therefrom of light, providing increased optical coupling efficiency as compared with that achievable by use of a mere prism structure.

Abstract: A connector to an optical fiber comprises a prism, a ferrule and an aspheric lens. The prism includes a triangular wedge element having a first surface, a second surface and a base. The ferrule guides the optical fiber so as to contact the optical fiber with the first surface of the prism. The aspheric lens is integrated on the second surface, the integrated aspheric lens being positioned so that the prism serves to redirect a light beam at an angle relative to an axis of the optical source input through total internal reflection by utilizing the base of the triangle wedge element. The aspheric lens serves to collimate the redirected light beam or focus the light beam before being redirected. This arrangement may, for example, be used within a WDM system to multiplex and de-multiplex several wavelengths of light, using a “zig-zag” optical path configuration and thin film filters to separate the wavelengths.

Abstract: The liquid crystal display device has red, green, and blue LEDs, each emitting a different color light, as a light source. An acrylic lens is mounted on the emission surface of the LED to change angular distributions of light from the LED. The shape of the acrylic lens varies depending on the color of the LED. The angular distribution of emitting light thereby differs by the color of LED to cancel out wavelength dependency of transmittance at each viewing direction in a liquid crystal panel.

Abstract: A method for compensating for chromatic dispersion of an optical signal includes: receiving the optical signal from an input fiber; collimating the optical signal using a collimator; delivering the collimated optical signal to a Gires-Tournois interferometer; reflecting a chromatic-dispersion-compensated optical signal from the Gires-Tournois interferometer to the collimator; focusing the chromatic-dispersion compensated optical signal into an output fiber. The compensator in accordance with the present invention provides flexibility in producing periodically varying chromatic dispersion so as to compensate for unwanted periodic chromatic dispersion produced in an interferometric interleaved channel separator. Also, the compensator enables compensation of fiber optic chromatic dispersion.

Abstract: A configurable wavelength multiplexing device having first, second, and third reflectors. The first reflector has a first state in which it transmits incoming light (having first and second wavelengths) along a first transmitted path and a second state in which it reflects the light along a first reflected path. The second reflector reflects the first wavelength and transmits the second wavelength. The third reflector reflects the first wavelength. The first, second, and third reflectors are oriented so that when the incoming light is transmitted along the first transmitted path, the first wavelength is reflected by the second and third reflectors to travel along second and third reflected paths, the third reflected path intersects the first reflector at an angle such that the first wavelength is transmitted by the first reflector and continues on the first reflected path, and the second wavelength is transmitted by the second reflector.

Abstract: The present invention relates to a device for use in a fiber optic system that may be a communication system, a sensing system or other system using guided-wave optical components. Reducing the number of lenses required to couple the waveguides and the free-space paths in the device offers the dual advantages of a reduced component count and simplified alignment. In an exemplary device having a first and second waveguides, a birefringent optical system defines bi-directional, polarization-dependent free-space paths. One of the bidirectional, polarization-dependent, free-space paths couples at least the first waveguide to the second waveguide. The birefringent optical system includes at least one prism for bending one of the polarization-dependent paths in a clockwise direction and one of the polarization-dependent paths in a counterclockwise direction.

Abstract: The present invention uses the deflection of a piezoelectric element to move an optical element into contact with the face of an optical path to redirect an optical signal. In its undeflected state, the optical signal is reflected from the angled face of the optical path by internal reflection. When the piezoelectric actuator moves the optical element into contact with the angled face of the optical path, the index of refraction of the optical path is matched and the optical signal enters the optical element and passes through.

Abstract: The linear dispersion of a dispersive optical system is increased by: (a) employing a transmissive diffraction grating (6) as a dispersive element; and (b) passing light through the grating twice. A reflector (7) is used to achieve the double passage through the grating. The system can be used to disperse light into its composite wavelengths (e g., the system can be a wavelength demultiplexer) or to combine dispersed light at different wavelengths into composite light (e.g., the system can be a wavelength multiplexer). The system can be employed in wavelength division multiplexed (WDM) optical communication systems.

Abstract: A device includes a first fiber collimator, a second fiber collimator, a third fiber collimator, a first beam splitting prism, a second beam splitting prism, a spacer, a resonator cube, and a dielectric beam splitting coating. The dielectric beam splitting coating separates the second beam splitting prism from the resonator cube. The spacer and the first fiber collimator straddle the first beam splitting prism. The first beam splitting prism and the second beam splitting prism straddle the spacer. The second fiber collimator and the spacer straddle the second beam splitting prism. The third fiber collimator and the spacer straddle the second beam splitting prism.

Abstract: A method of coupling laser-radiation into an optical fiber includes providing a stack of diode-laser bars and first and second parallel mirrors, the second mirror is selectively reflective only for one polarization plane of the laser-radiation. Each of the diode-laser bars includes at least two spaced-apart diode-laser emitters each emitting a plane-polarized beam of laser-radiation having a fast axis and a slow axis. The laser-radiation beams are collimated in the fast axis by a cylindrical lens located in front of each bar. In one arrangement the polarization orientation of one collimated beam from each diode-laser is rotated by 90 degrees and transmitted through the selectively-reflective mirror. The other collimated beam from each diode-laser bar is reflected onto the selectively-reflective mirror by the first mirror and reflected from the selectively-reflective mirror such that the reflected beam combines with the transmitted beam to form a combined beam.

Abstract: In an optical transmission and reception module, a partitioning member separating a light emitting device and a light receiving device from each other includes a partitioning plate having a concave surface, an engaging portion to which the partitioning plate is fixed, a holding portion holding the engaging portion movably, and a leaf spring for pressing the engaging portion against an optical plug. An end surface of an optical fiber is convex and projects from a front end of the optical plug. When the end surface of the optical plug is in contact with an engaging surface of the engaging portion, a gap is generated between the end surface of the optical fiber and a surface opposed thereto.

Abstract: The present invention provides an improved optical wavelength switch in which no mechanical movement is required to direct optical pathways between several fiber ports. The inventive three-fiber port device divides incoming optical signals into two subsets of spectra and selectively directs them into two output ports in response to an electrical control signal. In the inventive switch, an optical signal is spatially split into two polarized beams, by a birefringent element, which thereafter pass through a series polarization rotation elements and recombine into output fibers, achieving polarization independent operation. Advantageously, the inventive switch incorporates two-stage polarization rotations to improve isolation depth, as well as temperature and wavelength independence. The invention also incorporates light bending devices to allow two fibers to be coupled to the light beams via a single lens, thereby achieving small beam separation for compactness.

Abstract: A system and method of monitoring a laser output power and laser extinction ratio includes an optical subassembly physically placed between a point light source and a optical fiber device. The optical subassembly creates a convergent light beam by reflecting a collimated light beam from the point light source off an interior surface of a first side of the optical subassembly. The optical subassembly creates an incident ray of the convergent light beam by including on a second side of the optical subassembly a wedge-shaped air gap.

Abstract: An optical communication system includes an input optical fiber, an output optical fiber, and first and second Risley prism pairs disposed in an optical path between the input optical fiber and the output optical fiber. A first actuator is configured to independently rotate a first and a second prism of the first Risley prism pair so that a first light beam is steered to be incident on the second Risley prism pair by adjusting the first Risley prism pair. A second actuator is configured to independently rotate a third and a fourth prism of the second Risley prism pair so that a second light beam is steered to be incident on the first Risley prism pair by adjusting the second Risley prism pair, providing optical beam alignment of the optical path for communication and optical switching.

Abstract: Optical signals of which wavelength is multipled and which are transferred via an optical fiber 10 make incidence to refractive index distributing lens 34 and are converted into substantially parallel light beams, the optical signals converted make incidence into a polarized light conversion element 20a and are separated therein into two light beams and are emitted in a form of two linear polarized light beams of which polarization direction are aligned. The linear polarized light beams are separated by wavelength separation filters 28a, 28b and 28c, and make incidence with every two wavelength components either into a polarized light conversion element 20b or into polarized light conversion element 20c, and the optical paths for the light beams separated into two by the polarized light conversion element 20a are joined to form one light beam path for every waveform component.

Abstract: The optical multiplexer/demultiplexer comprises an input/output channel array, a diffractive element, an arraying device and a converging element. The input/output channel array is located adjacent an optical axis and includes input/output channels arrayed in a first direction, orthogonal to the optical axis, at a predetermined pitch. The diffractive element is arranged to receive light from the input/output channel array at a location separated from the input/output channel array along the optical axis. The diffractive element diffracts the light to array the light wavelength-dependently in a second direction, different from the first direction. The arraying device receives light diffracted by the diffractive element and arrays the light in the first direction at a pitch equivalent to the predetermined pitch. The converging element is located along the optical axis between the diffractive element and either or both the arraying device and the input/output channel array.

Abstract: Linear polarized light beams are separated by wavelength separation filters 28a, 28b, and 28c, and make incidence with every two wavelength components either into a polarized light conversion element 20b or into polarized light conversion element 20c, and the optical paths for the light beams separated into two by the polarized light conversion element 20a are joined to form one light beam path for every waveform component. The optical signals of the four wavelength components are reflected either by a mirror 31b or by a mirror 31c, are converged by such as a hologram lens 40c, and, after being reflected by a mirror 32, are detected for every wavelength component by the photo detector array 36.

Abstract: An optical fiber includes a core doped with a preselected gain material, an inner cladding disposed about the core, an outer cladding, disposed about the inner cladding, that has a section removed to expose a portion of the inner cladding, a notch disposed in the exposed portion of the inner cladding, and a mirror disposed within the notch that includes a high reflectivity surface oriented so as to reflect light launched into the mirror from an outside source into the fiber. The mirror, e.g. a right-angle trihedron, has a high reflectivity (HR) coating on one face, is inserted into the notch, and affixed thereto with an adhesive such as an optical cement. Pump light, e.g. from a laser diode, is launched through a face of the mirror that is antireflection (AR) coated or sufficiently transparent to the light frequency, and after reflecting off the HR face exits through a third face and into the fiber.

Abstract: An optical switch (10) includes an input device (11), a reflection output device (12), a transmission output device (13), a prism (2) and a rotation device (3). The input and reflection output devices are rotatable around the prism between a first position and a second position. The prism has a reflective surface (21) to effect optical switching. When the input and reflection output devices are at a first position, an input light beam from the input device passes through the reflective surface of the prism, and is output through the transmission output device. When the input and reflection output devices are at a second position, the input light beam from the input device is incident on the reflective surface of the prism at an angle which is equal to or larger than a critical angle of the prism. The input light beam is totally reflected by the reflective surface of the prism and is output through the reflection output device.

Abstract: Optical frequency-division filters for multiplexing and demultiplexing operations by combining wavelength-selective filtering and polarization properties of optical signals.

Abstract: An optical subassembly utilizes a core with a first, second, and third faces. The first and second faces are coupled, non-parallel, and non-co-planar for changing a path of a beam, and their intersection defines an axis. Filters are coupled to the third face. The light path traverses between the first or second face and each filter such that, at each filter, no portion of the light path interferes with any other portion of the light path. The light path also traverses the core in a direction along the axis. This is facilitated by the light path traversing an external surface of a filter at an angle. The device includes adjustable ports residing at the same side of the device. Filters are coupled to the core and optically coupled to the adjustable ports. The light path travels down the core and exit or enter the device via the adjustable ports.

Abstract: The present invention provides improved optical switches in which only a spatial beam shifting of a small free space offset is required to direct optical pathways between plural fiber ports. This is achieved by spacing two fibers closely and collimating their beams with one imaging lens for compactness. Advantageously, the inventive switches incorporate beam correcting devices to render the beam propagations parallel, allowing light beams to be efficiently coupled into two fibers that sharing a single lens with substantially improved stability.

Abstract: An apparatus and method for switching one or more optical paths comprises one or more inputs and one or more outputs arranged with one or more free-space optical paths formed therebetween, and one or more prisms movable to the free-space optical paths being inserted into or removed from the free-space optical paths to control the propagation paths of one or more light beams between the inputs and outputs. When the prism is inserted into the free-space optical path, a switched optical path between the inputs and outputs is formed to direct the light beam with two refraction and one total reflection by the prism. When the prism is removed from the free-space optical path, the light beam propagates along the free-space optical path.

Abstract: Multiplexed grating and grating/prism devices are particularly suited to DWDM optical telecommunications networks, finding utility in optical spectrum analyzers (OSAs) and fiber multiplexer/demultiplexers. The invention may be used to address both single- and dual-band configurations through adjustment of the grating, detector array, and/or inclusion of a fiber-optic switch. As a dual-band OSA covering the C- and L-bands, a device according to the invention may be used to replace two separate OSAs like those currently in production, at only a modest increase in cost relative to a single-band OSA.

Abstract: An optical element according to the invention uses a thin film-like two-dimensional photonic crystal having a structure of periodic repetition in two directions perpendicular to each other. When the two periodic directions are Y-axis and Z-axis directions, opposite surfaces of the photonic crystal structure perpendicular to the Z-axis direction and parallel to the Y-axis direction are used as a light input surface and a light output surface respectively. The direction of movement of light rays incident onto the light input surface is decided so that it is parallel to the YZ plane and inclined at a predetermined inclination angle to the Z-axis direction.

Abstract: This invention discloses an optical collimator that includes a built-in tap-out projection optical arrangement for projecting a portion of an incoming beam to a tap-out beam-transmission fiber. In one of the preferred embodiments, the built-in tap-out projection optical arrangement further includes a front surface having an incline angle for projecting a portion of an incoming beam to a tap-out beam transmission fiber. In another preferred embodiment, the built-in tap-out projection optical arrangement further includes a prism having a pair of inclined front surfaces for projecting the incoming beam into an output beam and a tap out beam. In yet another preferred embodiment, the built-in tap-out projection optical arrangement further includes a partially reflective front surface and a reflective mirror projecting the incoming beam into an output beam and a tap out beam.

Abstract: This specification discloses a light signal interleaver, which can separate a light signal into two light signals with a large interval in between. A birefringent plate is used as a light signal interleaver to separate all wavelengths in a light signal into an O-ray and an E-ray. Therefore, the invention can increase the total transmission capacity under the existent network structure.