Abstract: An implanted microphone is provided that allows for isolating an acoustic response of the microphone from vibration induced acceleration responses of the microphone. The present invention measures the relative motion between a microphone diaphragm, which is responsive to pressure variations in overlying media caused by acoustic forces and acceleration forces, and a cancellation element that is compliantly mounted within a housing of the microphone, which moves primarily in response to acceleration forces. When the microphone and cancellation element move substantially in unison to acceleration forces, relative movement between these elements corresponds to the acoustic response of the microphone diaphragm. This relative movement may be directly measured using various optical measuring systems.

Abstract: A fiber optic mode scrambler includes a multi-mode optical fiber formed with a core and a cladding around the core and a non-adiabatic cross-sectional shape change zone in the optical fiber. The fiber further has a bending region extending over a length of the optical fiber. The optical fiber has a non-zero curvature at the bending region and a device for maintaining the curvature of the optical fiber at the bending region. Mode scramblers can be provided that are accurately adjusted to match with different desired optical characteristics. A well-controlled manufacturing method for the mode scrambler is also described.

Abstract: An optical microphone includes: a light source; a first polarizer for allowing linearly-polarized light, of light output from the light source, to pass therethrough; a second polarizer for allowing linearly-polarized light having a different polarization plane from the first polarizer to pass therethrough; a sound-receiving section including an acoustic medium having a smaller sound velocity than the air, wherein an acoustic signal propagates through the acoustic medium, the sound-receiving section being arranged so that the linearly-polarized light from the first polarizer passes through the acoustic medium and enters the second polarizer; and a photodetector for converting an intensity of light having passed through the second polarizer to an electric signal, wherein between the first polarizer and the second polarizer, the linearly-polarized light having passed through the first polarizer is given different phase shifts in two orthogonal directions which are each different from a polarization direction.

Abstract: An optoelectrical connector is composed of a plug to which a wire and an optical fiber are assembled and a receptacle to which the plug is inserted and connected. A receptacle includes insulation sleeves and conductive contacts in openings of receptacle housings, and plugs include a ferrule assembled bodies which are composed of an insulation ferrule which holds an optical fiber and a conductive cylindrical member which holds the ferrule and to which a wire is assembled, in an opening of the plug housing. When the plugs are inserted into the receptacle, the contacts and the cylindrical member contact with each other and the ferrules are inserted into the sleeves. Parts which serve electrical connection are not exposed.

Abstract: An optical transmission module has an optical transmission path in which optical transmission is performed between a first circuit board and a second circuit board disposed opposite the first circuit board. The optical transmission path has a folded structure having a bending radius. A circumferential portion drawn by the bending radius is provided substantially perpendicular to board surfaces of the first circuit board and the second circuit board.

Abstract: An arrangement of gravity modulator and gravity-modulation receiver where photons or electromagnetic radiation is modulated electronically or mechanically to reach either a solid, liquid or mixed target possibly through or followed by a surrounding medium to produce gravity modulation in the target to effect gravity signaling which is received by a gravity-modulation receiver in or not in physical contact with the target. In the receiver, one or more piezo-electric transducer/s or quartz crystal/s receive the gravity modulation amplified for further signal processing. When not in physical contact with the target, the piezo-electric transducer/s is/are loaded with a resonator mass of natural resonant frequency either equal to, half, one third or one fifth of the frequency of the gravity modulator, the quartz crystal/s is/are gravity biased with a high-density metal piece along one direction of the oscillation mode of the crystal/s with natural resonant frequency similar to the resonator mass.

Abstract: Method for performing signal processing for an optical microphone. First and second signals corresponding to at least two beams may be generated or received. The first and second signals may be complementary, and may be based on signals provided by one or more photo detectors that receive the at least two beams after the beams return from a sensing structure. The first signal and the second signal may be subtracted to produce a third signal. A position of the sensing structure may be adjusted to cause the third signal to reach a first value, where the adjusting may be performed based on the third signal, and an audio output signal may be provided based on the third signal.

Abstract: A first exemplary aspect of the present invention is a wavelength-tunable optical transmitter including: a semiconductor substrate (101); a wavelength-tunable light source that is formed on the semiconductor substrate (101) and includes at least a first reflector (102) of a wavelength-tunable type and a gain region (104); a semiconductor optical modulator formed on the semiconductor substrate (101); a first semiconductor optical waveguide (105c) that is formed on the semiconductor substrate (101) and smoothly connected to the wavelength-tunable light source; a second semiconductor optical waveguide (105d) that is formed on the semiconductor substrate and smoothly connected to the semiconductor optical modulator; a waveguide coupling region (108) in which the first and second semiconductor optical waveguides are collinearly coupled with a length LC that is not equal to m/2 (m: integer) times a complete coupling length LC0; and a second reflector (113) formed at an end of the waveguide coupling region (108).

Abstract: An optical ultrasonic microphone includes an acoustic waveguide that transmits a sound wave received from an opening, an optical acoustic propagation medium that forms at least one portion of a wall face of the acoustic waveguide and an LDV head, and a sound wave proceeding through the acoustic waveguide is received by the optical acoustic propagation medium so that a change in the refractive index caused by the proceeding sound wave inside the optical acoustic propagation medium is generated with high efficiency, and by detecting this as an optical modulation by the LDV head, the optical ultrasonic microphone is allowed to have a very wide band.

Abstract: A thermoacoustic device includes a sound wave generator and an infra-red reflecting element having an infrared reflection coefficient higher than 30 percent. The infra-red reflecting element can be disposed at one side of the sound wave generator to reflect the emitted heat of the sound wave generator.

Abstract: An acoustic system includes a sound-electro converting device, a electro-wave converting device, and a sound wave generator. The electro-wave converting device is connected to the sound-electro converting device. The sound wave generator is spaced from the electro-wave converting device and includes a carbon nanotube structure. The sound-electro converting device converts a sound pressure to an electrical signal and transmits the electrical signal to the electro-wave converting device. The electro-wave converting device emits an electromagnetic signal corresponding to the electrical signal and transmits the electromagnetic signal to the carbon nanotube structure. The carbon nanotube structure converts the electromagnetic signal into heat, and the heat transfers to a medium causing a thermoacoustic effect.

Abstract: A sound wave generator includes a carbon nanotube film. The carbon nanotube film comprises a plurality of carbon nanotubes entangled with each other. At least part of the carbon nanotube film is supported by a supporting element. The carbon nanotube film produces sound by means of the thermoacoustic effect.

Abstract: An apparatus includes a signal device, a power amplifier, and a sound wave generator. The power amplifier is electrically connected to the signal device. The power amplifier outputs an amplified electrical signal to the sound wave generator. The sound wave generator produces sound waves by a thermoacoustic effect. The amplified electrical signal is positive or negative.

Abstract: An optical and electric signals transmission apparatus includes a receptacle having a light-receiving element and/or a light-receiving element and electrical connecting terminals, a plug having electrical connecting terminals to establish electrical coupling with the receptacle and optical coupling with the light-emitting element and/or the light-receiving element, an electric signal transmission line, and an optical signal transmission line. The receptacle has a fitting recess, and when the plug is fitted in the fitting recess in a direction substantially perpendicular to the optical axis of the light-emitting element or the light-receiving element, the optical coupling, the electrical coupling, and engagement of the receptacle with the plug are established at a location where the fitting recess and the plug are adjacent to each other.

Abstract: An optical ultrasonic microphone includes an acoustic waveguide that transmits a sound wave received from an opening, an optical acoustic propagation medium that forms at least one portion of a wall face of the acoustic waveguide and an LDV head, and a sound wave proceeding through the acoustic waveguide is received by the optical acoustic propagation medium so that a change in the refractive index caused by the proceeding sound wave inside the optical acoustic propagation medium is generated with high efficiency, and by detecting this as an optical modulation by the LDV head, the optical ultrasonic microphone is allowed to have a very wide band.

Abstract: An optical to radio frequency detector comprises an optical guide for receiving two optical signal components having frequencies that differ by an amount corresponding to a radio frequency, and a radio signal guide coupled with an interaction zone of the optical guide for propagating a radio signal from the interaction zone at the radio frequency. The material of the interaction zone presents a second-order non-linear optical polarization characteristic to the propagation of the optical signal components, and the radio signal guide is in travelling-wave coupling with the interaction zone. A radio signal output is coupled with the radio signal guide.

Abstract: An arrangement for a fiber optic microphone having at least one pair of optical fibers, each having an input end portion and an output end portion made of a material having a critical refractive angle ?crit and having a numerical aperture NA. The input end portion of a first fiber is connectable to a source of light and the output end portion of a second fiber is connectable to a photoelectrical transducer. Both end portions have an inner diameter, an axis and a rim. The input and output end portions are mutually affixed along a single plane with their rims touching each other at a point, the axes forming an angle ? therebetween. The rims are cut with respect to the axis, at an angle in a plane perpendicular to the single plane and to a bisector of angle ? at the point, where ?=2×?crit?NA.

Abstract: The present invention is provided to obtain an inexpensive bidirectional optical module wherein a diffraction efficiency can be maximized at different diffraction order for light beam with different wavelength, and light usage efficiency is enhanced. The bidirectional optical module includes a light-emitting element for transmitting an optical signal toward an end of an optical fiber; a light-receiving element for receiving an optical signal from the end of the optical fiber; and a grating in which stair shapes are repeated with a predefined pitch. In the bidirectional optical module, a phase function is defined as phase-difference contour lines which is formed by making two light fluxes from predetermined positions interfere with each other on a surface arranged at a position of the grating. A planar pitch of the grating is formed such that values of the phase function form phase contour lines each representing an integer multiple of 360 degrees.

Abstract: Various embodiments of duplex fiber optic connectors and optical transceiver modules are provided. One embodiment comprises an optical transceiver module comprising: an integrally-formed housing having a duplex front port with a pair of alignment holes for receiving a pair of ferrules from a duplex fiber optic connector, the duplex front port having an upper flexible retaining element and a lower flexible retaining element for retaining the pair of ferrules from the duplex fiber optic connector; an opto-electronic assembly contained within the housing; and an electrical interface extending from the integrally-formed housing.

Abstract: An optical transceiver includes a housing formed to be inserted into or extracted from a cage in a host device, a movable lock member for preventing the housing from being extracted from the cage, where the cage includes a lock hole for preventing the housing from being extracted from the cage when the movable lock member is placed into the lock hole, and an integration parts.

Abstract: A directionally-sensitive device for detecting and processing vibration waves includes an array of polymeric optical waveguide resonators positioned between a light source, such as an LED array, and a light detector, such as a photodiode array. The resonators which are preferably oriented substantially perpendicularly with respect to incoming vibration waves, vibrate when a wave is detected, thus modulating light signals that are transmitted between the light source and the light detector. The light detector converts the modulated light into electrical signals which, in a preferred embodiment, are used to drive either the speaker of a hearing aid or the electrode array of a cochlear implant. The device is manufactured using a combination of traditional semiconductor processes and polymer microfabrication techniques.

Abstract: An optical communication system is provided which includes an optical signal transmitter which communicates high bandwidth, high power frequencies. The optical signal transmitter includes a high efficiency/high power optical source such as an optical magnetron or a phased array source of electromagnetic radiation, and a modulator element. The modulator element may be within a resonance cavity of the high efficiency/high power optical source (intra cavity) or external to the cavity (extra cavity). The modulator element serves to modulate output radiation of the high efficiency/high power optical source to produce a modulated high frequency optical signal which may be transmitted through the air. The optical signal transmitter is particularly useful in providing the last mile connection between cable service operators and end users.

Abstract: The present invention discloses an interface circuit for a fiber transceiver, comprising: an encoder, for receiving and encoding an input data into an output differential signal; a comparator, for receiving an input differential signal from the fiber transceiver and generating an input signal; a decoder, for receiving the input signal and generating an encoded signal and an input data; and a detector, for receiving the encoded signal and generating a link signal supplied to the decoder to generate the input data.

Abstract: An On-Off control circuit between the IEEE1394a and IEEE1394b compliant physical layer (PHY) output driver circuitry and the glass fiber optical physical medium dependent (PMD) sub-layer within the architecture of the IEEE 1394b standard addresses the stability issue incurred by electronic circuit's inherent noise that interferes with the connection detecting procedure defined by the connection management protocol (CMP) of the IEEE 1394b standard. The circuit includes of a voltage divider to provide a reference voltage of about 50% of the output common mode voltage, a voltage comparator, and a feedback coupled to the positive input of the comparator to eliminate possible oscillation. The negative input of the comparator may be connected to the mid point of TPB termination network and the positive input of the comparator may be connected to the output of the voltage dividing circuit. The output of the comparator may be connected to the transmission enable bar input of the optical transceiver.

Abstract: Apparatus and methods for transferring audio between a headset and electronic equipment over an optical link. The apparatus includes an electro-optical interface for electrically connecting to the electronic equipment, an optical link, and an electro-optical headset. Audio from the electronic equipment modulates a light source in the electro-optical interface. A modulated light signal is transmitted through the optical link to the electro-optical headset where it is demodulated and reproduced as the original audio in the ear of a user wearing the headset. Also, another audio from the user's mouth produces another modulated light signal in the electro-optical headset. The other modulated light signal is transmitted through the optical link to the electro-optical interface where it is demodulated to provide the other audio to the electronic equipment. The non-electrical optical link may improve audible communications between the electronic equipment and the headset in radio-frequency noisy environments.

Abstract: Internal communication signals in a stored program controlled system comprising a plurality of units configured to process signals are provided by a free space optical beam line which is proximal to all of the plurality of units. The free space beam line is configured to contain optically encoded signals which comprises signals transmitted between and/or among the plurality of units. Each unit includes a probe for injecting optically encoded signals in the free space beam line and/or and for receiving optically encoded signals from the free space beam line. Advantageously, there may be a first terminal at a first end of the beam line to configure to transmit and terminate the optically encoded signals and a second terminal unit at the second end of the free space beam line configured to transmit and terminate the optically encoded signals.

Abstract: A method of increasing capacity on a long-haul undersea cable system having at least one optical fiber, said method comprising interleaving counter-propagating forward-propagating and backward-propagating signals in forward and backward channels on a common optical fiber, wherein the wavelength offset between said forward and backward channels is typically half of the channel spacing of co-propagating signals.