Abstract: An interleaver/de-interleaver circuit comprising: a first coupler having an input port and at least two output ports; a second coupler having two input ports and two output ports, the at least two output ports of the first coupler being optically coupled with the two output ports of the second coupler; an optical cavity having a partially reflective surface having a reflectivity E at one end and a reflective surface at another end with a higher reflectivity E′, the optical cavity being optically coupled to one of the at least two output ports of the first coupler and at one of the two output ports of the second coupler.

Abstract: An optical apparatus is disclosed that includes a first Z×T optical switch having Z input ports and T output ports, where T is at least 2, optically coupled to an integrated optical generalized Mach-Zehnder interferometer. The result is an optical switch, which is operated using a smaller number of control elements and control levels than the generalized Mach-Zehnder interferometer alone.

Abstract: Apparatus and method for catheterized delivery or infusion of medication and anaesthesia are disclosed. The perforating catheter is first used to perforate the periodontal ligament and/or the cortical plate of bone tissue, and is then left in place and used as a catheter for insertion of a hypodermic needle of smaller gauge to deliver medication or anaesthesia to a target area. The perforator is a bevelled needle for drilling into the ligament or bone tissue. For drilling, the device comprises an adaptor which transmits the rotational movement from a dental hand piece or the like to the bevelled needle. A cap is also included for protecting the bevelled needle during storage of the device. The adaptor may have a rod which extends axially into the bevelled needle when the device is assembled for drilling. The rod is used to prevent the debris resulting from drilling from blocking the passage in the bevelled needle.

Abstract: This invention discloses and optical filtering arrangement wherein a filter element having a coated substrate is disposed such that its ports on one side face the substrate instead of facing the coating upon the substrate. Hence, when the filter is positioned a distance from the ports, its coating side faces away from the ports while its substrate faces the ports. In this arrangement stress applied by adhesives or solder upon the coating can be eliminated.

Abstract: A broadband optical amplifier that can provide a constant amplifier gain profile, correct for ASE noise, and minimize gain tilt by dynamically controlling different stages of the amplifier through a combination of gain, loss, and power control of each stage depending on input and the desired output level. The multiple stage amplifier has a central control circuit independently controlling each stage, the amplifier comprising a plurality of sequentially coupled stages, each stage being an attenuator stage, a gain setting sub-amplifier stage, or a power level setting stage. The central control circuit determines which stages are actively gain or power controlled.

Abstract: The present invention relates to multi-wavelength filtering devices and more particularly to a multi-channel multiplexer/demultiplexor using at least one multi-port optical circulator and a plurality of Bragg optical fiber gratings or other wavelength selective means. Advantageously a drop or add/drop optical circuit including the combination of a Bragg grating providing a strong reflective response for substantially completely separating a single channel of a band of wavelengths from a plurality of other channels in a multi-channel signal, with a Bragg grating of lower reflective response which is capable of providing group delay compensation to lessen the effects of group delay introduced by the strong Bragg grating with isolation between the Bragg gratings provides a device for accurately and efficiently separating channels from a multiple channel signal with low loss.

Abstract: An optical amplifier having a substantially flat response over a multi-channel bandwidth for signals which have different input levels. It utilizes input and output photodetectors for detecting amplitude variations. The gain can be determined by a microprocessor receiving signals derived from the photodetectors, which causes change in the gain of the amplifier. The microprocessor calculates output ASE noise content at different amplifier input levels and subtracts that noise from the total power received by the output detector thereby determining an accurate amplifier gain value. The gain setting offered by the amplifier will then be the same as what is desired by a network management system.

Abstract: Broad wavelength tuning range are achieved in an effectively reset-free, optical, automatic polarization controller by providing a device and method for varying the polarization of an input beam of light. A block of electro-optic material has two pairs of electrodes for applying a voltage across the block. Light is launched into an input end of the block for receiving the input beam of light. A controller controls a quadrature voltage applied to the first and a second pair of electrodes; the quadrature voltage has the form of a magnitude and an angle. The quadrature voltage can be varied in such a manner as to orient a given electric field within the electro-optic material through a plurality of angles, for example between 0 and 2&pgr; radians; the magnitude of the quadrature voltage can be set to create an arbitrary retardance from 0 to 2&pgr;. Any output polarization state can be realized by appropriately varying the magnitude and angle of the voltage applied to the Vx and Vy electrodes.

Abstract: 1. A lensed sleeve has a holder having at least two substantially parallel rows of optical fibers which are offset from one another by about 2 &mgr;m or more. Generally these defective offset sleeves have to be discarded as their offset inhibits proper coupling of light, however in accordance with this invention a lens is disposed to receive light from at least optical fibers within one of the at least two rows of optical fibers. By using symmetry about the lens, light can be efficiently coupled between particular fibre ends on the offset rows. Advantageously, this invention provides a use for otherwise useless sleeves which did not meet intended tolerances.

Abstract: A broadband light source is fabricated from an optical transmission medium having an amplification material such as rare earth doped (e.g. erbium) fiber. The natural emission spectrum of this amplification material is corrected. The weak emission wavelength region has been enhanced and the whole spectrum flattened. The source outputs high power with about 25% pump efficiency. The spectrum is stable and the power density is equalized through out the emission region.

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.

Abstract: An optical device that includes a filter element which affects a beam incident thereon by shifting it is provided with a lens, wherein a distance between the lens end face and the filter is different than the distance between the lens end face and the input waveguide. By ensuring an appropriate difference in distance, optimum coupling is achieved even in view of the beam shift from the filter.

Abstract: An add-drop optical circuit is provided comprising: a first multiplex/demultiplexer for demultiplexing a composite optical signal having a plurality of channels, a second multiplex/demultiplexer for multiplexing a plurality of signals into a composite optical signal; waveguides disposed between the first demultiplexer and the second multiplexer/demultiplexer; and a plurality of 11/2.times.2 optical switches coupled to at least some of the waveguides for adding and dropping optical signals, the optical switches substantially preventing optical signals from propagating from an add port to drop port.

Abstract: An optical switch mechanism for reflecting an input light beam from an input port to a reflection output port in a first state and for transmitting an input light beam to a transmission output port in a second state is disclosed. The switch mechanism comprises a block made of a light transmissive substrate. The block contains a cavity, which is divided by a light transmissive diaphragm into a reflective portion and a transmissive portion. At the input port a light beam is coupled into the block such that the light beam encounters a reflective surface at an angle greater than a critical angle determined by the refractive indices of the substrate and a reflective fluid retained in the reflective portion of the cavity. When the reflective fluid is in contact with the reflective surface the light beam is totally reflected to a reflection output port.

Abstract: The present invention relates to an optical coupling between an end of an optical fiber and an end of a lens, which provides a reliable joint with a determined spacing and angular orientation. The optical coupling permits movement of the end of the optical fiber relative to the lens in at least two alignment directions. Advantageously, the present invention permits movement of the end of the optical fiber relative to the end of the lens in a direction perpendicular to the optical axis of the lens, before the optical coupling is secured. The optical fibre within an optical fiber tube/ferrule and the lens are secured within separate sleeves and the sleeves bonded together. The end of the optical fiber and the end of the lens are optically aligned before being secured in place relative to each other.

Abstract: An optical element having a periodically varying spectral response is used to flatten the spectral amplitudes within each of a group of multiplexed channels having different predetermined central wavelengths with uneven spectral amplitudes peaked around the central wavelengths. Spectral equalization is achieved by having the amplitude valleys of the spectral response aligned individually with the different central wavelengths. The optical element comprises an optical cavity, which forms part of a low-finesse Fabry-Perot etalon.

Abstract: On-line measurements of an amount of dissolved solids in a liquid sample are determined by using both conductivity and UV measurements. More particularly, an amount of dissolved solids in a pulp and paper mill process water or effluent is determined by irradiating at least a portion of a liquid sample with ultraviolet light and subsequently measuring an absorption of the light by the liquid sample. Furthermore the conductivity of the liquid sample is measured and subsequently a computation is from a first relationship between the measured absorption of the first wavelength by the liquid sample and the measured conductivity of the liquid sample using a suitably programmed processor.

Abstract: Faces are one of the most commonly recognized features among people. According to the invention a system for recognizing intensity images of faces is provided. Intensity images of a face are captured and normalized. The intensity images are transformed, filtered and then transformed again. The filter is based on a three-dimensional image of a face against which the intensity image is being compared. The result is a form of correlation that is substantially illumination independent.

Abstract: A straw splitter for longitudinally splitting pieces of cereal straw into separated strands for use in making a panel, board or beam is provided. A cutting shear roller and a gripping shear roller are rotatable around their longitudinal axis at different circumferential speeds. The pieces of straw are split due to shear between the cutting shear roller and the gripping shear roller. The shear rollers each comprise parallel grooves with cutting edges oriented at a predetermined angle to the roller axis such that the grooves of the gripping shear roller cross the grooves of the cutting shear roller providing a scissoring action for splitting the straw into long strands.

Abstract: A method and device for optical multiplexing or demultiplexing of optical signals. The device has a grating for dispersing an input beam into a plurality of sub-beams which are focused by a simple lens and a GRIN lens on a glass block having a plurality of waveguides embedded therein with a predetermined spacing therebetween. In order to correct for an offset in alignment, e.g. due to ambient temperature changes, between the sub-beams and the waveguides of the block, the latter is mounted to a thermally activated actuator for an controlled angular displacement which is selected to compensate for the offset.