Abstract: The present invention provides a straightforward and robust synthetic process for producing a chromatographic column with eluent-sensitive light diffracting properties based on an inherent photonic band structure and a chromatographic device using the chromatographic column. The present invention provides chromatographic devices employing a chromatographic column which in one embodiment is a photonic colloidal crystal which includes an assembly of colloidal microspheres assembled into a highly ordered array within a housing such as a tube with the highly ordered array being a photonic crystal along the length of the crystal, and a second embodiment which is an inverse construct of the first embodiment, where solid microspheres making up the photonic colloidal crystal chromatographic column are replaced with spherical voids or void spaces subsequent to infiltration of a material of selected refractive index.

Abstract: An optical device comprises a first substrate wafer with at least one buried optical waveguide on an approximately flat planar surface of the substrate and a second substrate wafer with at least a second buried optical waveguide. The waveguides so formed may be straight or curved along the surface of the wafer or curved by burying the waveguide at varying depth along its length. The second wafer is turned (flipped) and bonded to the first wafer in such a manner that the waveguides, for example, may form an optical coupler or may cross over one another and be in proximate relationship along a region of each. As a result, three-dimensional optical devices are formed avoiding the convention techniques of layering on a single substrate wafer.

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: Exemplary embodiments of the present invention provide for methods to launch data signals from single mode fiber optic cable into legacy multimode fiber optic cable. In one exemplary embodiment, a single mode fiber is offset slightly from the axis of a multimode fiber, thus only exciting the outer mode of the multimode fiber. In an alternate exemplary embodiment, a core portion of the single mode fiber is exposed, heated, and fused with a cladding portion of the multimode fiber. In yet another alternate exemplary embodiment, various lenses can be used to collimate and focus light signals from single mode fibers into multimode fibers, and vice versa. In these exemplary embodiments, the transmitted light signals can be in the range of from 1470 to about 1610 nm with, for example, a 20 nm channel separation. Other wavelengths and channel separations are also possible.

Abstract: A device and method for collecting subject responses, particularly during magnetic imaging experiments and testing using a method such as functional MRI. The device comprises a non-metallic input device which is coupled via fiber optic cables to a computer or other data collection device. One or more optical switches transmit the subject's responses. The input device keeps the subject's fingers comfortably aligned with the switches by partially immobilizing the forearm, wrist, and/or hand of the subject. Also a robust nonmetallic switch, particularly for use with the input device and methods for optical switching.

Abstract: A semiconductor-based optical amplifier/attenuator is disclosed. An apparatus according to aspects of the present invention includes an optical waveguide disposed in semiconductor material. A first optical beam having a first wavelength is to be directed through the optical waveguide. The optical waveguide is optically coupled to receive a pump optical beam having a pump wavelength. The pump optical beam also has a power level sufficient to amplify the first optical beam via stimulated Raman scattering (SRS) in the optical waveguide. A diode structure is disposed in the optical waveguide. The diode structure coupled is to be selectively biased to selectively control free carrier lifetimes of the free carriers in the optical waveguide. This enables to selective amplification or attenuation of the first optical beam output from the optical waveguide.

Abstract: A waveguide type variable optical attenuator is provided with a substrate for forming a waveguide for optical signal propagation; a waveguide element comprising 2 arm waveguides arranged on the surface of the substrate for constituting a portion of the waveguide and cladding for covering the arm waveguides and the surface of the substrate; and a heater arranged on the surface of the waveguide element for heating the arm waveguides. The 2 arm waveguides are connected thermally.

Abstract: A light controlling means includes a shutter member and an actuator. The shutter member is disposed in a slit and has a function to shut off signal light propagated in the light path of an optical fiber array. The actuator is constructed to drive and move the shutter member in a vertical direction. The shutter member is fixed to one end of the actuator and positioned substantially in alignment with an inclination angle of the slit. Further, a base member of the shutter member is made from transparent quartz glass. A light reflecting film is formed on a portion of one of the plate surfaces of the shutter member, on a surface opposite the optical axis of a light exit portion.

Abstract: A single pulse laser beam of linear polarization is irradiated to a glass region such that the condensing point is located inside of the glass region, thereby to form, at the condensing point, a periodic structure region in which high refractive-index zones and low refractive-index zones are repeatedly being generated at pitches of 1 ?m or less. Planes in which the high refractive-index zones or the low refractive-index zones are being joined to one another, are formed in parallel to the polarized magnetic field direction of the pulse laser. It is therefore possible to prepare an optical structural body having a submicron-order fine periodic structure which can readily be produced.

Abstract: The present invention provides an ultra-thin high-precision glass optic and method of manufacturing the same. The optic has an axial thickness that is less than 1,000 microns. A pattern and/or coating is disposed on a surface of the optic to provide attenuation of light in an optical system. In an embodiment, the optic is manufactured by disposing a pattern on a surface of a reticle. The pattern is covered with a first protective coating to protect the pattern. Individual optics are cut from the reticle so that each optic includes a portion of the pattern. The optic is thinned by removing material until it has an axial thickness of less than 1,000 microns. The optic is cleaned after thinning and covered with an anti-reflective coating.

Abstract: The present invention comprises an arrayed waveguide grating member, a taper multimode interference coupler and a taper optical attenuator to uniform and flatten a passband in an optical device.

Abstract: An improved waveguide shuttle optical switch design which provides the function of a variable optical attenuator (VOA). A small degree of intentional misalignment of the waveguide will create different levels of optical attenuation. By finely controlling the misalignment of a selected switched position, a single device may be realized that will provide the functions of both switching and attenuating or just attenuation alone. The optical MEMS device utilizes a latching mechanism in association with a thermal drive actuator for aligning a waveguide shuttle platform. The integration of the switching function and the VOA function reduce the optical loss which is otherwise unavoidable when the inevitable alternative of a separate switch and a separate VOA must necessarily be employed. The resultant improved device can also be applied for correcting the difference in optical intensity created by the manufacturing tolerances inherent in the fabrication of array waveguide gratings.

Abstract: The invention relates to compensating for the wavelength dependent loss (WDL) in a variable optical attenuator (VOA) system by using a chromatic dispersion wedge, which is inserted between the mirror and the lens. Different wavelength components, e.g. shorter blue and longer red wavelengths, are redirected at different angles by the chromatic dispersion wedge and now arrive at the output fiber at different positions. Thus the smaller mode field diameter (MFD) or mode spot size of the blue light, overlaps more of the core of the output fiber by being closer thereto and now has less insertion loss (IL) as compared to a VOA without WDL compensator.

Abstract: An optical filter includes at least one waveguide structure. The optical filter also includes a plurality of optical resonators that are aligned in an coupled arrangement with the at least one waveguide structure so as to produce an asymmetric distribution of coupling coefficients.

Abstract: A high dynamic range integrated (HDRI) receiver includes a variable optical attenuator (VOA) for attenuating an incoming optical signal before the optical signal is directed to a photo-detector for conversion into an electrical signal. An optical block receives the optical signal from an optical fiber and includes optics for directing the optical signal to the VOA, and for directing the optical signal from the VOA to the photo-detector.

Abstract: Devices utilize elements carried by a fluid in a microchannel to switch, attenuate, shutter, filter, or phase shift optical signals. In certain embodiments, a microchannel carries a gaseous or liquid slug that interacts with at least a portion of the optical power of an optical signal traveling through a waveguide. The microchannel may form part of the cladding of the waveguide, part of the core and the cladding, or part of the core only. The microchannel may also have ends or may be configured as a loop or continuous channel. The fluid devices may be self-latching or may be semi-latching. The fluid in the microchannel is moved using e.g., e.g., electrocapillarity, differential-pressure electrocapillarity, electrowetting, continuous electrowetting, electrophoresis, electroosmosis, dielectrophoresis, electro-hydrodynamic electrohydrodynamic pumping, magneto-hydrodynamic magnetohydrodynamic pumping, thermocapillarity, thermal expansion, dielectric pumping, and/or variable dielectric pumping.

Abstract: Apparatus and methodology for the low coupling of optical fibers in high power applications. An end of a single mode optical fiber, or a polarization maintaining fiber, is cut and spliced to a relatively short segment of an index matched multi-mode fiber or an optical fiber without cladding (air cladded) having approximately similar diameter as the single mode fiber which in turn is coupled to the external device. The free end of the multi-mode fiber may be cleaved, polished and have an anti-reflection applied to it. The beam emitted by the small core of the single mode optical fiber expands into the larger core of the multi-mode fiber providing low loss high power coupling of the optical fiber to the external device.

Abstract: An optical level calculator calculates optical powers of individual wavelengths of a through wavelength division multiplexed signal based on an input level monitor, network information, and insertion loss information 5, and obtains an optimum level for an add signal. An optical level controller controls a power of the add optical signal to the optimal level based on the calculated result, and multiplexes the through wavelength division multiplexed signal and the add optical signal.

Abstract: The present invention relates to controlling parameters of an optical output of an optical transmitter. An optical package can be selected based on a level of attenuation of a parameter of a transmitter output by the optical package. The laser and the optical package can be assembled and a parameter of the transmitter output can be measured. An optical barrel can be selected based on the measurement, wherein the optical barrel is selected based on an attenuation level to satisfy a range of a desired parameter value. The optical package and the optical barrel can be assembled. A system for assembling the optical device is also described.

Abstract: The present innovation discloses the design, configuration and process of a kind of MEMS-based tunable optical devices. The devices can be classed as dual-cavity of Fabry-Perot resonators, which consist of a first outer membrane, a middle membrane and a second outer membrane. And these membranes are separated by cavities. The membranes will deflect under electrostatic force and the thicknesses of cavities will change. The numbers of the layers of membranes should satisfy an equation. These devices can be adopted for optical switches, VOA or tunable filters.

Abstract: A wavelength selective switch architecture for ROADMs for switching the spectral channels of a multi-channel, multi-wavelength optical signal between input and output ports employs a biaxial MEMS port mirror array for optimal coupling efficiency and ITU grid alignment, an anamorphic beam expander for expanding input optical signals to create an elongated beam profile, a diffraction grating for spatially separating the spectral channels, an anamorphic focusing lens system, an array of biaxial elongated channel MEMS micromirrors, a built-in Optical Channel Monitor, and an electronic feedback control system. The bi-axial channel micromirrors are rotatable about one axis to switch spectral channels between ports, and are rotatable about an orthogonal axis to vary the coupling of the spectral channel to an output port and control attenuation of the spectral signal for complete blocking or for a predetermined power level.

Abstract: A variable optical attenuator includes an optical fiber on an incident side and an optical fiber on an emission side; a polarization rotator element that includes a liquid crystal layer and a pair of substrates that are arranged in such a manner that the liquid crystal layer is sandwiched between the substrates; and a Savart plate that is arranged between the optical fibers and the polarization rotator element. In the polarization rotator element, rotation of a polarizing direction is controlled by controlling a birefringence characteristic of liquid crystal, which is controlled by controlling alignment of the liquid crystal layer.

Abstract: A line attenuation device for monomode fibers having at least one attenuating element with at least one graded-index multimode fiber section placed between two monomode fibers and coupled to at least one coreless silica fiber section.

Abstract: An improved cantilever beam optical switch design which provides the function of a variable optical attenuator (VOA). A small degree of intentional misalignment of the waveguide will create different levels of optical attenuation. By finely controlling the misalignment of a selected switched position, a single device may be realized that will provide the functions of both switching and attenuating or just attenuation alone. The optical MEMS device utilizes a latching mechanism in association with a thermal drive actuator for aligning a cantilever beam platform. The integration of the switching function and the VOA function reduce the optical loss which is otherwise unavoidable when the inevitable alterative of a separate switch and a separate VOA must necessarily be employed. The resultant improved device can also be applied for correcting the difference in optical intensity created by the manufacturing tolerances inherent in the fabrication of array waveguide gratings.

Abstract: In a method of manufacturing an optical attenuator, a bonding medium layer of polymer is used to bond an actuator structure and a support structure. A silicon layer is provided with waveguides for transmitting optical signals from an optical signal transmission line and an activator is formed at a predetermined portion thereof. The waveguides are inserted into cavities of the bonding medium layer. A support layer is attached to the bonding medium layer at an opposite face to a face where the bonding medium layer is bonded with a silicon substrate.

Abstract: A method for controlling the attenuation of an optical element. A base material, such as a resin, is selected from which to fabricate the optical element. The base material has an intrinsic attenuation or intrinsic absorption spectrum. A predetermined concentration of a first type of dye molecule is then added to the base material to vary the intrinsic attenuation of the base material to achieve a predetermined absorption spectrum.

Abstract: A reflective optical switch comprises an input/output port portion; a polarization separator/combiner for separating lights in the same optical path and combining lights in different optical paths; a Faraday rotation angle changer; a polarization rotator for changing the relationship in polarizing direction between lights in different optical paths; a birefringence element for optical path control for controlling optical path shift in response to polarizing direction; and a polarization rotating reflector for rotating polarizing direction 90 degrees on forward and return paths. The input/output port portion, the polarization separator/combiner, the Faraday rotation angle changer, the polarization rotator, the birefringence element for optical path control, and the polarization rotating reflector are arranged along the optical path, and the Faraday rotation angle changer includes a Faraday element and an electromagnet for controlling 90-degree change in polarizing direction of transmitted light thereof.

Abstract: Provided is a planar optical waveguide circuit type variable attenuator capable of light attenuation by an arbitrary value in a range from 0 to 10 dB and also by not less than 30 dB, which is small-sized and is of power saving type. The attenuator is composed of a Mach-Zehnder interferometer circuit 30 having input waveguides 1a, 1b and an output waveguide 1d which are formed on an optical waveguide layer 3, and comprises a slit 12 formed on the waveguide layer in a longitudinally intermediate part of at least one of the optical waveguides 1a, 1b, 1d and in a direction crossing the optical waveguides 1a, 1b, 1d, and matching medium displacing means 16a, 16b for displacing index-matching medium 13 in a part of the slit 12 from a position including a path of propagation light in the optical waveguides 1a, 1b, 1d, and a position retracted from the path of propagation light.

Abstract: A technique for manufacturing optical fixed attenuators in which two fibers are axially cojoined using fusion splicing. The spliced fibers are then captured in either a splice protection splint or cylindrical ferrule that can be housed in an optical adapter. In this process for producing the attenuator, the fusion splicing is preceded by a deformation of the mode field diameters of the ends of the fibers with the cleaning arc function of the splicing unit. The resulting attenuation of the splice is dependent on the amount of deformation of the fiber core and mode field diameter. Such a technique enables precision attenuation with very low wavelength dependent loss to be fabricated. The performance of Dense Wavelength Division Multiplexing systems, as well as test facilities and individual optical components can be improved by the use of such attenuators.

Abstract: An apparatus for attenuating a light signal is disclosed. The apparatus causes optical attenuation in a waveguide, where the waveguide has an input port for receiving a light signal and an output port for output of an attenuated light signal. First, an electric field is generated in at least a portion of the waveguide, such that a first refractive index in that portion of the waveguide is changed to a second refractive index. Next, the light signal in the waveguide is directed from the input port to the output port through the electric field. And lastly, the light signal is attenuated as a function of the electric field. The light signal may be attenuated, for example, by changing the deflection angle, changing the beam collimation width or from emitting part of the light signal from the waveguide before the light signal reaches the output port.

Abstract: In an endoscopic system there is a source of radiation and a waveguide, which is symmetric about an axis and receptive of the radiation for guiding the radiation therealong. A coupling mechanism engages or disengages the waveguide to or from an endoscope. An attenuator is deployable in a first position when the waveguide is engaged to the endoscope and deployable in a second position when the waveguide is disengaged from the endoscope. When the attenuator is deployed in the first position, the radiation passes from the waveguide to the endoscope and when the attenuator is in the second position, the radiation is at least partially blocked from passing from the waveguide to the endoscope or from exiting the fiber optic cable.

Abstract: An optical transmission module and method are capable of suppressing the occurrence of multiplexed reflection light, thereby making it possible to easily carry out an optical coupling operation at low cost. A loss generator having an attenuation factor determined based on an extinction ratio of a modulation signal is provided to attenuate reflection light in a transmission path, thereby making it possible to provide a low-cost optical transmission module, which ensures a practically satisfactory efficiency, without providing an optical isolator component. Also, in the optical transmission module, the intensity of light is adjusted by the loss generator. Thus, it is possible to realize the optical transmission module using an optical mounting technique with such accuracy as employed for an ordinary module.

Abstract: Described herein are one or more embodiments of a system and method for managing power in an optical network using a variable optical attenuator (VOA). In one embodiment, the attenuation of the VOA is controlled in a feedback loop in accordance with a plural zone method. In one example, the VOA is a mechanical VOA. In another example, the VOA is a latching VOA.

Abstract: The present invention provides an apparatus comprising a passive optical transmission fiber. The passive optical transmission fiber comprises a passive glass fiber core, a glass optical inner cladding surrounding the core and a glass optical outer cladding surrounding the inner cladding. The inner cladding has a lower index of refraction than the passive glass fiber core and the outer cladding has a lower index of refraction than the inner cladding. The passive optical transmission fiber also comprises a second optical segment coupled to the optical fiber. The second optical segment is configured to dissipate light in the inner cladding.

Abstract: An optical switching apparatus includes an optical switch having a plurality of input ports and output ports, optical amplifiers, monitor circuits, optical amplifiers monitor circuits, and a controller that controls the optical switch. The optical amplifiers are connected to the input ports of the optical switch. The monitor circuits are connected to the output ports of the optical switch. The controller selects one of the plurality of the monitor circuits based on predetermined rules to obtains the loss at the output ports and/or the differential loss between the channels of the optical switch. The controller further selects one of the optical amplifiers based on the configuration of the optical switch to compensate the loss and the differential loss among the different channels of the optical switch by pre-amplifying the optical signals before they reach the input ports of the optical switch.

Abstract: Disclosed herein is a cantilever-type PLC optical attenuator. The optical attenuator includes a base substrate made of silicon, an input waveguide, and output waveguide. Front portions of the upper and lower silicon substrates around the output waveguide are thinner than rear portions of the upper and lower silicon substrates around the output waveguide to provide a cantilever part having upper and lower cantilever substrate parts. A first electrode is provided on a bottom of the lower cantilever substrate part, and a second electrode is provided on the base substrate to electromagnetically correspond to the first electrode. When a voltage is applied between the first and second electrodes, the cantilever part moves up and down by an electromagnetic force, thus controlling the output light.

Abstract: Two mirrors (15) and (16) making an angle of 90 degrees are formed on a front face of a mirror member (17). An optical fiber for input (12) and an optical fiber for output (13) are held in a fiber array (14) with a predetermined interval, and an emission lens (23) and an injection lens (24) are provided on a front face of the fiber array (14) in a way that they are opposed to end faces of the optical fiber for input (12) and the optical fiber for output (13) respectively. According to the variable optical attenuator, when the mirror member (17) is straightly moved by an actuator (18), light attenuation can be varied thereby.

Abstract: A thermo optical type variable optical attenuator suitable for application in an array type variable optical attenuator that realizes low crosstalk between neighboring waveguides in the array is provided. A thermo optical type variable optical attenuator 100 using optical material having negative optical effect provides a multimode optical propagating part 3 disposed via a tapered part 2 and a tapered part 7 between single mode optical waveguides 1 and 8. A thin-film heater 4 is disposed above the multimode optical propagating part 3 at an angle of inclination ? in relation to the direction of light propagation along a first optical waveguide 50. Moreover, a second optical waveguide 9 optically coupled with a side face 3S1 of the multimode optical propagating part 3 is provided at an angle of inclination 2? in relation to the direction of light propagation along the first optical waveguide 50.

Abstract: An all optical chopping device for shaping and reshaping comprising an all optical AND logic gate having a first input for receiving a first optical signal, a second input for receiving a second optical signal and at least one output. The AND gate may be arranged to produce at least at one output thereof an optical output signal corresponding to a portion of the AND product of the first optical signal and the second optical signals. The optical output signal may be narrower than at least one of the first optical signal and the second optical signal.

Abstract: A variable optical attenuator has a first and second waveguides that are optically coupled together. At least one of the waveguides has a movable cantilever portion that is movable relative to the other to control attenuation of an optical signal traveling between the two. Preferably, electrically driven actuators deflect the movable waveguides to a relative position at which a desired optical attenuation value is achieved. The electrically driven actuator receives a drive signal that controls the amount of deflection. The drive signal may be set to achieve a desired value for an electrical parameter that varies with the position of the movable waveguide and may be sensed by the electrically driven actuator. In some examples, the drive signal is set to achieve a desired capacitance or voltage difference between the movable waveguide and an electrode.

Abstract: Optical package and module designs use multiple-port (e.g. six-port) optical packages to create compact DWDM modules, add/drop packages, heat dissipation packages, optical amplifier filters, and the like.

Abstract: A multi-source optical module is described that includes an optical circuit positioned on a base. The optical circuit includes a first and a second optical input. A first and a second optical source are positioned on the base relative to the optical circuit. A first lens is positioned between an output of the first optical source and a first input of the optical circuit. A second lens is positioned between an output of the second optical source and a second input of the optical circuit. At least one of the first and the second lenses are positionable so that the output of a respective one of the first and second optical sources and a respective one of the first and the second optical inputs of the optical circuit are aligned.

Abstract: A multi-channel optical switching system particularly usable as a programmable optical add/drop multiplexer (POADM) in a multi-wavelength communication system. The switching system uses a thin film optical demux/mux that separates a multi-channel optical signal into a plurality of optical channels, and combines a plurality of optical channels into a multi-channel optical signal. The system also uses a plurality of optical ports optically connected to the thin film optical demux/mux and a selecting device to select which optical channel is directed to which of the optical ports.

Abstract: A method and an apparatus to provide optical equipment protection have been disclosed. In one embodiment, the method includes diverting a predetermined portion of each of a plurality of optical signals to a plurality of photonic detectors within a first optical network node, and detecting the plurality of signals using the plurality of photonic detectors, each of the plurality of photonic detectors being designated to detect one of the plurality of optical signals. Other embodiments have been claimed and described.

Abstract: A telecommunications system is formed from a single mode optical fiber carrying Wave Division Multiplex (WDM) traffic. A transmission fiber coupler is arranged to couple signals from channels to be added to the single mode optical fiber. A coupler connects the channels carrying the signals to be added to the input of an optical amplifier, the output of the amplifier being connected in series to the transmission fiber coupler by a switchable multiband band-stop filter arranged to pass only signals having the wavelength of a signal or signals to be added to the WDM traffic. The switchable multiband band-stop filter may be a fiber Bragg filter, a selectable stack of filters or an assembly of bleachable filters. A switchable multiband filter is formed from a stack of layers of a semiconductor bleachable medium whereby the bleaching threshold is that of each single layer and the attenuation is the sum of the transmissions through all the layers comprising the stack.

Abstract: A non-circular, mechanically variable optical attenuator using a pair of specially constructed polarizing elements with means enabling a gradual transition from un-crossed polarization vector fields to crossed polarization vector fields using a linear motion with respect to one another. The polarizing elements whose polarization axis varies with spatial position on the element have a polarization vector field that is a function of position on the element. Specifically, the two polarizing elements have a defined orientation of polarization axes or vectors on the polarization vector fields that vary with spatial location on the polarizing element such that when aligned light passes, and when the polarization axes are crossed, light is attenuated. The present attenuator has a practical application for dimmable mirrors or windows by providing a variable optical attenuator that is purely mechanical and non-circular in shape.

Abstract: A variable optical attenuator (VOA) for use in an optical fiber communication system has a substrate, a thermal gradient prism and a heating element deposited on the prism. Heat is applied to the thermal gradient prism through the heating element. An optical signal is input into the prism via an optical signal input source. The optical signal traveling through the prism may be deflected due to a thermal gradient of the prism. The deflected optical signal is output into an optical signal output carrying medium. An optical signal strength measuring apparatus may measure a parameter related to the strength of the optical signal output into the optical signal output carrying medium.

Abstract: A solar filter assembly combines a high-precision Fabry-Perot etalon with a variety of conditioning filters judiciously selected to effectively block completely all radiation except for the spectral line of interest. In addition, a tuning mechanism is provided to precisely control the peak frequency of the filter's output by varying the optical length of the etalon's cavity.

Abstract: A laser diode that emits light of a predetermined wavelength, an optical fiber that propagates the light emitted from the laser diode, and a transmission liquid crystal variable optical attenuator that is arranged on an optical axis of the light between the laser diode and the optical fiber and attenuates light intensity of the light are arranged inside a housing. A coupling lens couples the light emitted from the laser diode to an incidence end of the optical fiber. An isolator prevents return light from the optical fiber side.

Abstract: An optical attenuator for attenuating a collimated beam of light propagating along an optical path while preserving the composition of polarization of the collimated beam of light is disclosed. The optical attenuator comprises a beam attenuator for attenuating a portion of the collimated beam of light when a portion of the beam attenuator is disposed within the optical path. The beam attenuator has a cross section along a plane perpendicular to the direction of propagation of the collimated beam of light of the portion of the attenuator in the shape of a wedge. The attenuation is varied using a controller for moving the beam attenuator in order to vary a size of the portion of the wedge within the optical path.