Abstract: A system comprising a plurality of comparison samples configured to substantially simulate the appearance of a keratinous element. Each comparison sample may be configured to substantially simulate both a color and an appearance characteristic other than color of the keratinous element.

Abstract: A ground contamination detector has a duct (21) having an annular opening (21a). The annular opening blows air toward the ground (1) to form an air curtain that defines an enclosed space (2A) between the duct and the ground. The detector also has a pipe (23) having a nozzle that opens in the enclosed space and jets heated air toward the ground, to promote the evaporation of noxious substance (3) and diffuse the evaporated gas in the enclosed space. The detector also has a suction pipe (24) to suck the evaporated gas from the enclosed space and a sensor (25) to analyze the sucked gas. The enclosed space formed by the air curtain defines a detection area on the ground, and the detector collects and analyzes contaminants in the enclosed space in a noncontact way. The detector is installable on a vehicle, to efficiently detect the presence and position of contaminants on the ground in real time.

Abstract: The invention provides a dispersion compensation system and method formed by cascading a series of GT cavities with three setting parameters, reflectivity, resonant wavelength, and free-spectral-range. In one aspect of the invention, the GT cavities can synthesize any shape of combined dispersion compensation, including positive, negative, slope dispersion compensation. In another aspect of the invention, the GT cavities are tunable or dynamic to accommodate various types of dispersion compensation. Advantageously, the present invention provides an effective cost solution for a more precise dispersion compensation tuning.

Abstract: A method is for three-dimensionally, optically measuring measuring objects by comparison with a reference object, where image data of the measuring object are acquired and compared to image data of the reference object, and the measuring object is directly or indirectly assessed with regard to deviations from the reference object. A quick and, at the same time, reliable assessment of the measuring object is achieved in that the measuring object and/or the reference object or a holographic recording of the measuring object and/or of the reference object are/is rotated relative to one another about at least one axis, the image data of the measuring object being acquired and the comparison being performed in various, relative rotational positions, in that an evaluation regarding a maximum agreement of the measuring object with the reference object is performed in the different comparisons, and in that the deviation is assessed in the rotational position determined by the maximum agreement.

Abstract: A method and circuit are presented for an all-optical format independent preprocessor that processes an arbitrary optical input signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. The method involves subtracting a delayed copy of the signal from the original, thereby effectively doubling its frequency, and inserting a pulse at each transition of the original signal, whether rising or falling. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The asymmetry consists of a delay element in one arm. In a preferred embodiment the entire device is fabricated on a semiconductor substrate, allowing for compactness as well as minimization of interconnectivity losses and overall power consumption. The output of the preprocessor, having a significant frequency component at its original clock rate, can then be fed to a clock recovery stage for all-optical clock recovery.

Abstract: An interferometric measuring device for detecting the shape of rough surfaces includes a spatially coherent beam gun unit that emits a short time coherent and broad-band beam. The device is separated into a section containing the components of a modulation interferometer and the components of a measuring probe. The measuring probe is coupled to the modulation interferometer via an optical fiber arrangement, and used remotely from the modulation interferometer.

Abstract: The invention features a displacement and dispersion measuring interferometry system having a Helium-Neon laser light source. The light source can be a Helium-Neon laser that includes an intracavity doubling crystal and an intracavity etalon to generate two harmonically related, single-frequency wavelengths at sufficient powers for interferometric dispersion measurements. Alternatively, the light source can be a single-mode Helium-Neon laser that directs a single-frequency input beam into a resonant external cavity enclosing a doubling crystal to generate two harmonically related, single-frequency wavelengths at sufficient powers for interferometric dispersion measurements. In addition to dispersion measurements, the inherent wavelength stability of the Helium-Neon source permits high-accuracy displacement measurements.

Abstract: Apparatus for measuring the surface profile of a sample, includes a fixture for locating a surface of a transparent optical flat relative to a surface of a sample; a low-coherence light interferometer having an optical probe coupled to an XY scanning frame for scanning the surface of the sample through the transparent optical flat to produce interferometric data signals representing the distances between the optical flat surface and the surface of the sample; and a computer system responsive to the interferometric data signals for generating a surface profile of the sample using a best fit to a plane.

Abstract: A measurement interferometer (40) having a frame structure (43), a laser source (12), a detector (14), a beam splitter (18), a reference retroreflector (28), a reference holder (20) and a test retroreflector (30). The reference rertoreflector (28) and beam splitter (18) are disposed in fixed relation to the reference holder (20) to constitute a splitter-holder assembly (16). The test retroreflector (30) and the splitter-holder assembly (16) are movable relative to each other and both are movably mounted on the fine structure (43). Preferably, the test retroreflector (30) is situated between the reference holder (20) and the beam splitter (18). In a particular embodiment the beam splitter (18) is connected to the reference holder (20) by a carbon composite rod (22), and the test retroreflector (30) is mounted on a probe (34) made from a carbon composite. In one embodiment, the reference retroreflector (28) is integral with the beam splitter (18).

Abstract: A system for measuring the spatial dimensions of a three-dimensional object employs a lens and at least two detectors. The combination of which defines two or more object planes. The combination of the lens and the detectors define an optical axis that is normal to the object planes and passes through a focal point of the lens. At least a first and a second photodetector are optically aligned with the object through the lens. The first and second photodetectors or array of detectors are further parallel with the surface but have differing elevations relative to that surface. In addition, the first and second photodetectors are capable of motion relative to said object. Electrical output from the first and from the second photodetectors is provided to a processor that determines a distance of the object from the lens and thereby a height of the object. This system is particularly suited for measuring the spatial dimensions of solder balls mounted to a surface of a ball grid array (BGA) electronic package.

Abstract: An image capturing apparatus for obtaining information regarding a depth of a subject includes: an illumination unit operable to cast a first illumination light beam that mainly contains a first wavelength and has a first intensity distribution on a plane perpendicular to an optical axis of the first illumination light beam and a second illumination light beam mainly containing a second wavelength and a third wavelength and having a second intensity distribution on a plane perpendicular to an optical axis of the second illumination light beam onto the subject, the second and third wavelengths being different from the first wavelength, the second intensity distribution being different from the first intensity distribution; and a depth calculation unit operable to calculate a depth-direction distance to the subject based on outgoing light beams from the subject.

Abstract: Provided is a visual displacement sensor which comprises a laser diode (112) for impinging a line beam onto an object to be measured at a prescribed angle, a two-dimensional CCD (122) for monitoring the object to be measured, on which the line beam is impinged, from a different angle, measurement object range defining means for defining one or more than one measurement object range (K11, K12) within a field of view of the two-dimensional CCD, measurement point coordinate determining means for determining one or more than one measurement point coordinate (A7) contained in the defined measurement object range according to an image captured by the two-dimensional CCD, and displacement measuring means for measuring a desired displacement according to the determined one or more than one measurement point coordinate.

Abstract: An image forming apparatus having a receipt interface I/F, a hard disk, and a printer section. The receipt interface I/F receives pages of image data transmitted and a partial print request signal requesting that only a part of the image data be printed, both transmitted through a communication line. The hard disk stores both the image data and the partial print request signal. The printer section prints a part of the image data stored in the hard disk, in response to the partial print request signal that the receipt interface I/F has received.

Abstract: The states of plural image output apparatuses are sensed. Then, an image output apparatus, which will supply image data, is selected according to a size of an image output job on the basis of image data and the states of the image output apparatuses in such a manner as to reduce an electric power consumption required for outputting images.

Abstract: The disclosure relates to methods and apparatus for handling error occurrences in an image outputting system. The system comprises plural multifunction peripherals (MFPs) for printing a document. Each MFP is communicatively coupled to a single control unit, the control unit being communicatively coupled to a computer workstation on a computer network. The control unit receives a print job from the computer workstation and then sends the print job to one or more hard output units. The control unit monitors the status of the print job with respect to each MFP to determine whether an error is present in any of the MFPs. If the control unit detects an error, it waits a predetermined time period to provide a user time to fix the error. If the user does not fix the error within the predetermined time period, the control unit then polls the status of the remaining MFPs to determine whether any other MFPs are error-free. The control unit then sends the print job to one or more of the error-free MFPs.

Abstract: A multi-function peripheral device and method for printing from a multi-function peripheral device are presented. When a facsimile function is executed, half of an empty area of a flex memory and a FAX transmission/reception memory are set as a FAX transmission/reception memory. When a printer function is executed, half of an empty area of the flex memory and a printer memory are set as a printer memory. When a printer priority function is executed, all the empty area of the flex memory and the printer memory are set as a printer memory.

Abstract: A print job representing a visible output of a document is created from a print job representing the document. The print job contains page description language (PDL) commands. The PDL commands are sent to a computing device where executable code, such as a computer program, translates the PDL commands into a raster image. The raster image is then communicated to an input output (I/O) interface of an imaging system. The I/O interface communicates the raster image to a printing subsystem where the raster image is printed. The print job may be first sent to the computing device for creating the raster image, then the raster image sent to the imaging system. Alternatively, the print job may be first sent to the imaging system where it is redirected to the computing device. The print job is then communicated to the computing device where the raster image is created from the print job. The raster image is then returned to the imaging system for printing.

Abstract: A first image processing portion, using respective synchronization signals for ‘n’ blocks of image data, performs first predetermined image processing on the image data. A second image processing portion combines the ‘n’ blocks of image data in line units, and performs second predetermined image processing on the image data using synchronization signals, the period of each of which is ‘n’ times the period of each of the respective synchronization signals. A third image processing portion again divides each line of image data into ‘n’ blocks of image data, and performs third predetermined image processing on the image data using the respective synchronization signals, the period of each of which is the original period.

Abstract: A halftone dot area percentage is determined under desired output conditions as to a recording medium, an exposure condition, a printing condition, a screen ruling, a screen angle, and the like. Continuous tone correction data are generated from the halftone dot area percentage, and stored in a continuous tone correction data memory. A halftone dot corrector corrects desired continuous tone image data based on the continuous tone correction data. Then, the corrected continuous tone image data into halftone dot image data by halftone dot image data binary processor. A high-quality halftone dot image free of tone jump is generated from the halftone dot image data.

Abstract: There is provided a pseudo-halftone image expression method capable of processing vector data with an excellent image quality and small computational complexity. Gray levels of n×n/m are expressed by varying the number of formed dots within a matrix of n×n dots on an m-dot basis (where n denotes an integer of 8 or more and m denotes an integer of 4 or more). A dot formation rule corresponding to each gray level within a matrix is divided into at least two stages, form a low gray level to a high gray level. In a first stage, dots are arranged at random and in dispersion so as to separate a dot from each other. In a second stage, dots are extended in random directions in turn so as to prevent an island of successive dots from coupling with each other using the dots arranged at the first stage as a nucleus.

Abstract: A method for selecting CMY coordinates for printing a desired source color represented in an source color-space includes the step of obtaining coordinates for the printer gamut in the source color-space and then dividing the printer gamut into a plurality of tetrahedra, one of which contains the desired source color. This particular tetrahedron, referred to as the source-bearing tetrahedron, is identified and transformed into a target-bearing tetrahedron in the CMY color space. The target-bearing tetrahedron contains the CMY coordinates of the desired color. The specific color within the target-bearing tetrahedron is identified by obtaining barycentric coordinates for the source color relative to the source-bearing tetrahedron and identifying that color in the target-bearing tetrahedron that has the same barycenric coordinates. The CMY coordinates for that color can then be provided to a printer to print the desired source color.

Abstract: An apparatus and method for dither matrix design for color halftoning using dispersed dot clusters where the dot cluster centers are arranged in a homogeneous and isotropic pattern, in order avoid the moiré effect. The method requires that the size of the array and the number of dot seeds that will be in the array be predetermined.

Abstract: When images recorded in a memory card are read and reduced images of image files are displayed on a liquid crystal monitor in order, printing information of the image files is referred to. An image of which two or more prints have been designated is enclosed by a predetermined-colored (for example, yellow) frame, and a figure is displayed according the number of the prints that have been designated. An image of which any prints have not been designated is not enclosed by the frame. An image that has been printed is enclosed by an another-colored (for example, blue) frame.

Abstract: An image sensor according to the present invention includes a casing (4), a light source disposed in the casing (4) for emitting light toward an object (K) to be read, and an image sensor board (6) provided, on an obverse surface thereof, with a plurality of light receiving elements (52) for generating image signals upon receiving light reflected by the object (K). The image sensor board (6) is disposed so that the obverse surface thereof is directed inwardly of the casing (4). The substrate (6) is provided with a light shielding layer (61) for covering the reverse surface of the substrate at least entirely over a portion of the obverse surface where the plurality of light receiving elements (52) are mounted, so that disturbing external light is prevented from entering inside the casing (4).

Abstract: The image reading system comprises an image reading device and a computer, which can be connected to the image reading device to operate it. In the image reading device, a film, in which an image is recorded, is regularly intermittently moved, so that the image is read by a line sensor. In a pre-scanning operation, the film is moved with a pitch which is coarser than that of a regular scanning operation, so that a pre-view image is read by the line sensor, and is displayed on a screen of a liquid crystal display device. A control bar, indicated on the screen along with the pre-view image, is operated by handling a track ball and a click button, so that an image quality of the pre-view image is adjusted. Namely, even in a stand-alone mode in which the image reading device is operated independently from the computer, the image quality of the pre-view image can be adjusted.

Abstract: An image scanning method used in a scanner. The scanner includes a housing, a transparent platform set on the housing for a document to be placed on, a scanning module installed inside the housing for scanning the document, and a step motor for driving the scanning module step by step so as to scan the document. After completing a first scanning pass, the scanning module moves a predetermined distance, which corresponds to non-integer steps of the step motor so that when the scanning module performs a second scanning pass, sampling positions of the second scanning pass are different from sampling positions of the first scanning pass.

Abstract: An imaging system includes an imaging subsystem for forming an image on a sheet, a tray for holding a supply of sheets, a ramp for directing a sheet from the tray into a paper path, a sensor in the vicinity of the paper path, a drive assembly and a processor connected to the drive assembly and the sensor. The drive assembly includes a movable roller configured to move the sheet into the paper path by moving a top sheet of a supply of sheets in the tray to the ramp. The sensor is configured to detect a sheet traveling in the paper path from the tray and to provide an output signal in response to the detection. The processor is configured to control movement of the roller, to receive and store an initial sheet level value, to receive the output signal from the sensor and to calculate a time, t, from activating the drive assembly to receiving the sensor output signal and to accordingly adjust the initial sheet level value.

Abstract: Provided is an image processing method and a apparatus of converting a color input image or a partial region thereof in accordance with a color gamut of a color image output apparatus is provided. The method and apparatus is characterized in that only the region requiring color gamut compression can be put to color gamut compression depending on the distribution of an input image, that the direction of the color gamut compression can be controlled continuously for each of the regions; the amount of the color gamut compression can be controlled continuously including clipping, that when color gamut compression is conducted by a color converter of a multi-dimensional DLUT interpolating calculation type, an excessively unnecessary color gamut compression can be avoided particularly upon clipping, and that there is enabled correction for visual bending in iso-hue lines caused by distortion of a color space in each of the regions of the color space.

Abstract: An apparatus for a free space optical communication system includes an element having a front surface and a back surface. A holographic optical element (HOE) is disposed to receive a light signal from the free space optical communication system, and to angularly direct the light signal, having a certain wavelength, towards one of the surfaces of the element to allow the light signal to propagate between the front and back surfaces of the element via total internal reflection. The internally reflected light signal eventually converges and is received at an optical detector circuit. At the same time, light having other wavelengths, including visible background light, passes through the HOE, thereby giving the apparatus an appearance of being transparent and unobtrusive.

Abstract: An optical scanner, a laser image projector using the optical scanner, and a method of driving the laser image projector are provided. The optical scanner includes: a base substrate; a plurality of parallel stationary comb electrodes arranged on the base substrate extending upwards at right angle; a stage having a mirror side at its top side, being separated a predetermined distance above the base substrate; a plurality of parallel driving comb electrodes arranged on the bottom of the stage extending at right angle interdigitated with the stationary comb electrodes; torsion bars formed at both side edges of the stage with a predetermined length to support such that the stage pivots; and supports for supporting the torsion bars such that the stage is suspended above the base substrate.

Abstract: An angular sweep of a directed propagation of electromagnetic radiation is generated by a first oscillating or vibrating reflector that cooperates with at least one fixed reflector. Electromagnetic radiation, for example a laser beam, incident upon the first reflector is reflected to the fixed reflector with an angular sweep created by movement of the first reflector and in turn is reflected back to the first reflector at least once, each reflection back to the first reflector increasing again the angular sweep created by the previous reflection from the first reflector. Multiple reflections creating a wide angular sweep relative to the magnitude of the first reflector's movement.

Abstract: In a matrix-addressable optoelectronic apparatus which includes a functional medium in the form of an optoelectronically active material provided in a global layer in sandwich between a first and second electrode with parallel strip-like electrodes wherein the electrodes of the second electrode are oriented at an angle to the electrodes of the first electrode, functional elements are formed in the active material where respective electrodes overlap and correspond to optically active pixels in a display device or pixels in an optical detector, depending upon the active material used. In each of the first and second electrode, the electrodes are provided in a dense parallel configuration and mutually insulated by a thin film with a thickness that is only a fraction of the width of the electrodes.

Abstract: The present invention pertains to an optical shutter comprising an organic free radical compound, wherein the optical shutter is reversibly imageable to switch between a non-reflective and transparent state and a reflective state. This switching may be induced by the absorption of photons, the application of an electric current, or thermally. Preferably, the organic free radical compound is a salt of an aminium radical cation. Also provided are optical switch devices and optical buffers comprising such optical shutters, methods of switching an optical signal utilizing such optical shutters and switch devices, and methods of storing an optical signal utilizing such optical buffers.

Abstract: An electro-optic device has, on a TFT array substrate, a pixel electrode; a TFT connected thereto; a scanning line and a data line connected to the thin film transistor; a pixel potential side capacitance electrode that is connected to the pixel electrode and constitutes a storage capacitor; and a capacitance line that contains a fixed potential side capacitance electrode that is disposed oppositely via a dielectric film to the pixel potential side capacitance electrode and constitutes the storage capacitor. A width W1 of a portion that projects along the data line in the capacitance line is formed the same as or wider than a width W2 of the data line. Thereby, while realizing a lower resistance capacitance line, or an inhibition of an occurrence of a light leakage current in a TFT, an enhancement of an open area ratio can be satisfied.

Abstract: A liquid phase epitaxy method is used to grow the Faraday rotator with a small saturation field (Hs). The Faraday rotator has the formula: Bi3−x−y−zGdxTbyMzFe5−w−nGawPnO12, where M is selected from Y, Yb, Lu, and P is selected from Al, Si, Ge. X, y, w and n are chosen from the ranges of 0.5≦x≦1.0, 0.5≦y≦1.0, 0.2≦z≦0.5, 1.5≦x+y+z≦2.0, 0.5≦w≦1.0, 0.15≦n≦0.5, 0.8≦w+n≦1.2. Without M and P, a Type-L Faraday rotator with a linear BH curve is provided, which is well suited for variable optical attenuators. With M and P, a Type-R Faraday rotator with a rectangular hysteresis loop is provided, which is well suited for optical switches. Both are also well suited for use in optical isolators and circulators.

Abstract: An electromechanical conformal grating device including: at least two sets of elongated ribbon elements; a pair of end supports for supporting each elongated ribbon element at both ends over a substrate; a plurality of intermediate supports placed under each elongated ribbon element; and at least two inputs for selectively applying a force to the at least two sets of elongated ribbon elements; wherein the force causes selected elongated ribbon elements to deform between first and second operating states, wherein during the second operating state the elongated ribbon elements mechanically conform to the intermediate supports.

Abstract: This invention discloses a configuration of thin-film membrane. This thin-film membrane is freestanding, movable, and made of multiple layers of different materials such as silicon nitride, polycrystalline silicon or the combination of these two. This thin-film membrane can be actuated by external controlling forces such as electrostatic force. This thin-film membrane consists of odd number of layers, e.g., 1 layer, 3 layers, 5 layers, . . . , etc. Moreover, the layer profile of this membrane is symmetric, e.g., the bottommost layer is made to be identical to the topmost layer, the next bottommost layer is made to be identical to the next topmost layer, so on and so forth.

Abstract: A deformable mirror (10) with an at least quasi-continuously deformable optically effective surface (12) has a floatingly supported mirror plate (11) which is positioned along its edge by a portion of the adjusting members (14.1), whereas the other portion of the adjusting members (14.2) locally individually deforms the mirror plate (11) for the purposes of wave front correction. In that respect all adjusting members (14.1, 14.2) are fixed to the rear side (13) of the mirror plate (11), with a coupling portion (11) which is provided with a desired-flexion location (constriction (25)).

Abstract: A system and method of providing a micromirror pixel 400 that is highly resistant to bright failure states. The micromirror 400 uses an asymmetric yoke 402 to ensure the mirror is only attracted to the address electrode in one rotation direction. The landing mechanism on the other side of the torsion binge axis also is altered to allow the pixel to over rotate in the “off” direction. The over rotation ensures that light reflected by the mirror when in the off direction will miss the projection lens pupil, allowing the corresponding pixel to remain dark in both an operational and failed state.

Abstract: An electrophoretic display having a protective electrode that reduces the degradation of the display caused by mechanical or electrochemical action. The electrode can include a protective layer that reduces the mechanical or electrochemical damage to a transparent conductive electrode. The protective electrode can be a vapor permeable electrode that is a reticulated electrically conductive structure, such as a metal screen or wire mesh, or a reticulated structure coated or impregnated with a conductive material. The protective electrode can include a layer that protects the display media from physical abrasion or removal by mechanical action, while allowing the application of an electric field to cause the display to be addressed.

Abstract: An electrophoretic device is composed of a pair of electrodes that are arranged opposite to each other with a prescribed space therebetween, which contains an electrophoretic dispersion liquid containing electrophoretic particles which are dispersed in a liquid phase dispersion medium. At least one ferroelectric substance layer is arranged at a prescribed position within the space between the electrodes, and at least one of the electrodes is made of a transparent material. Applying a drive voltage between the electrodes, the electrophoretic particles are deposited on one electrode while ions of reverse polarity move towards another electrode, thus establishing the polarized state of the electrophoretic dispersion liquid, which is maintained for a long time due to the residual polarization characteristics of the ferroelectric substance layer.

Abstract: Electrophoresis display devices using charged particles which move in each cell in accordance with the electrophoresis caused by electrodes neighboring the cell. First through third electrodes are used to provide the electrophoresis to the charged particles in a dispersion liquid of each cell. The first and the second electrodes are formed in parallel with each other on a side of a first board and the third electrode is formed on a second board 5 to intersect with the first and the second electrodes. The first electrode may be applied with an initial voltage, a first hold voltage and a rewriting voltage between the initial voltage and the first hold voltage in an order of the first voltage, the rewriting voltage and the first hold voltage. The second electrode may be applied with intermediary voltage between the initial voltage and the rewriting voltage to the first electrode.

Abstract: The invention relates to a light wave converter assembly, comprising a light guide and a light wave converter, comprising a converter substance, which converts a part of the incident light into light of a longer wavelength, whereby the converted light is guided together with the unconverted light through the light guide to an exit port.

Abstract: A RF amplification system which includes a RF modulation unit fed by an optical carrier and an RF input signal, the modulation unit modulating the RF input signal onto the optical carrier to produce a modulated RF optical signal; an array of optical amplifiers coupled to the modulation unit for receiving and amplifying the modulated RF optical signals; and a detecting unit having at least one photodetector coupled to the array of optical amplifiers for receiving and detecting the modulated RF optical signals, the at least one photodetector producing an amplified RF output in response thereto.

Abstract: A Raman fiber amplifier includes: a transmission fiber; at least one optical pump providing optical pump power to the transmission fiber; and at least one pump power detector; at least one signal detector detecting signal power propagating through the transmission fiber. The Raman fiber amplifier also includes a controller that adjusts the pump power provided by the pump to adjust, gain, or signal power provided by this Raman fiber amplifier.

Abstract: Disclosed are an optical transmission system and a Raman amplifying control unit that can stabilize the effective loss of a transmission line even if the optical transmission system has a relay station between a transmitting station and a receiving station. The optical transmission system and the Raman amplifying control unit have an introducing means for outputting inspection light and introducing it to the transmission line, a receiving means for receiving the back-scatter from the inspection light, and a control means for inspecting the transmission line and controlling an exciting light supplying means according to the received backscattering light. The introducing means, the receiving means, and the control means are provided together with the exciting light supplying means in a station at the transmitting side or receiving side of a relay section in the optical transmission system.

Abstract: It is aimed at providing an inter-wavelength light power deviation monitoring method capable of directly measuring the signal light power to thereby detect the light power deviations among channels without requiring a higher wavelength resolution, and providing an optical equalizer and an optical amplifier adopting such a monitoring method. To this end, the monitoring method of the present invention comprises the steps of: obtaining channel information concerning WDM signal light; setting, based on the channel information, at least two measuring wavelength regions; measuring channel light power of the WDM signal light, for only the measuring wavelength regions; and obtaining light power ratio for the respective measuring wavelength regions making use of the measured values, to thereby judge the inter-wavelength light power deviations of the WDM signal light.

Abstract: Disclosed are an optical amplifier and an optical transmission system using the same in which not only can the dispersion of optical waveguide paths for optical amplification be easily and sufficiently compensated, but also the waveform degradation of signal light can be restrained. An optical amplifier according to one embodiment of the present invention comprises at least two erbium-doped fibers 10 and 20, having erbium doped to optically amplify signal light with the pump light, and having dispersion different from each other in sign, and being connected together in series, and two pump light sources 11 and 12 for supplying pump light to them.

Abstract: A method of forming a linear polarization-maintaining optical fiber for use in an amplifier, the method comprising the steps of: providing a rare-earth-doped non-polarization-maintaining optical fiber having one or more cladding layers and having a random birefringence; providing a mandrel having a selected diameter; coiling said non-polarization-maintaining optical fiber under a selected tension around said mandrel to induce a linear birefringence greater than said random birefringence in said non-polarization-maintaining optical fiber thereby forming a polarization-maintaining optical fiber; wherein said mandrel diameter is chosen to avoid significant bend loss; wherein said rare-earth dopant is selected from the group consisting Nd3+, Yb3+, Pr3+, Ho3+, Er3+, Sm3+ and Tm3+; wherein said mandrel diameter is selected to be from about 0.1 cm to about 10 cm; and wherein said tension is chosen to avoid undesirable weakening of said non-polarization-maintaining fiber.

Abstract: A projection screen comprising; a substrate having a generally flat forward surface; a diffusion layer formed of a plurality of generally equally spaced apart concave features forming micro lenses; a layer of reflective material deposited on a rearward facing surface of the diffusion layer; the diffusion layer laminated to the forward facing surface of the substrate so that the layer of reflective material is sandwiched therebetween.