Abstract: An optical cable having a metal tube receiving an optical fiber and bent to form a waved shape is disclosed. The optical cable may prevent cutoff of the optical fiber or deterioration of optical characteristics though tensile force is applied to the optical cable in its longitudinal direction since the metal is formed in a waved shape. To bend the metal tube, the metal tube is passed through roller pair(s) which are shaken in a direction perpendicular to the advancing direction of the metal tube. Thus, it is possible to obtain excess fiber length (EFL) easily and accurately as desired.

Abstract: Fiber optic drop wires extending from a cable closure supported along a fiber optic cable are supported by small horseshoe-shaped bend radius protectors which not only prevent overbending of the drop wires, but also enable one to store excess drop wire length on the bend radius protectors. The free end of the drop wire is clamped to a utility pole.

Abstract: High speed optical modulators can be made of a lateral PN diode formed in a silicon optical waveguide, disposed on a SOI or other silicon based substrate. A PN junction is formed at the boundary of the P and N doped regions. The depletion region at the PN junction overlaps with the center of a guided optical mode propagating through the waveguide. Electrically modulating a lateral PN diode causes a phase shift in an optical wave propagating through the waveguide. Each of the doped regions can have a stepped or gradient doping profile within it or several doped sections with different doping concentrations. Forming the doped regions of a PN diode modulator with stepped or gradient doping profiles can optimize the trade off between the series resistance of the PN diode and the optical loss in the center of the waveguide due to the presence of dopants.

Abstract: An optical fiber has a zero dispersion wavelength in a wavelength range of 1350 to 1410 nanometers; a dispersion of 2 to 8 ps/nm/km at a wavelength of 1550 nanometers; a dispersion slope of a positive value and not more than 0.05 ps/nm2/km at a wavelength of 1550 nanometers; a transmission loss of not more than 0.4 dB/km at a wavelength of 1380 nanometers; an increase of transmission loss of not more than 0.04 dB/km at a wavelength of 1380 nanometers after a hydrogen aging test; a transmission loss of not more than 0.25 dB/km at a wavelength of 1550 nanometers; and a bending loss of not more than 30 dB/m when the optical fiber is wound at a diameter of 20 millimeters at a wavelength of 1550 nanometers.

Abstract: An optical multi/demultiplexing circuit includes at least one phase generating optical coupler and an optical delay line coupled to the phase generating optical coupler. The phase generating optical coupler consists of at least one input and at least two outputs. At least one of the phase generating optical coupler has a wavelength dependent or frequency dependent output phase difference in the passband of the circuit so that it can change the transmittance characteristics of the optical multi/demultiplexing circuit.

Abstract: An apparatus (8, 14) for wavelength shifting light from a first frequency ?1 to a second frequency ?2 is provided in the form of a semiconductor intersubband laser (8) lasing at its intersubband frequency ?3. The output light is wavelength shifted to a frequency ?2=?1+n?3, where n is a non-zero integer ( . . . , ?2, ?1, 1, 2, . . . ). The wavelength shifted light ?2 may be amplitude modulated and/or frequency modulated to impart information upon it. The wavelength shifting is a coherent process allowing for the possibility of coherent communication techniques to be used.

Abstract: A wavelength conversion device including a nonlinear medium having quantum dots uses a tunable laser as an excitation light source of optical four wave mixing, and performs wavelength conversion for a wide bandwidth signal light with optical four wave mixing by employing a control apparatus for controlling an optical system including an optical path of a signal light and an optical system including an optical path of an excitation light in correspondence with a wavelength of a signal light that is to be wavelength converted.

Abstract: Materials suitable for use in non-linear optical devices comprise morpholinium or thiomorpholinium salts of hydroxy-substituted aliphatic or aromatic carboxylic acids selected from tartaric acid and hydroxy-substituted benzoic and cinnamic acids, which salts have a non-centrosymmetric crystalline form. Preferred salts include morpholinium 3-hydroxybenzoate, morpholinium 4-hydroxybenzoate, morpholinium 3,5-dihydroxybenzoate, morpholinium 3-fluoro-4-hydroxybenzoate, dimorpholinium 2,3,5,6-tetrafluoro-4-hydroxybenzoate, morpholinium 4-(4-hydroxyphenyl)benzoate, morpholinium tartrate, morpholinium 4-hydroxycinnamate, thiomorpholinium 4-hydroxy-benzoate and thiomorpholinium 3,5-hydroxybenzoate.

Abstract: An optical switch and method for assembling are described. Optical arrays are mounted on a flex plate with an interface between them. The direction of certain forces on the flex plate allows coupling/decoupling of the optical arrays. The flex plate includes an area which exhibits a different flex profile than the remainder of the flex plate and that is located beneath the optical arrays interface. Flexing of the flex plate optically couples the optical arrays. A tool with grooves is used to align the optical arrays relative to each other. The tool uses grooves and spheres to mate with the optical arrays in such a way as to provide an appropriate interface between the optical arrays.

Abstract: An integrated optical mode transformer provides a low loss interconnection between an optical fiber and an integrated optic waveguide having a spot size different from that of the fiber. The mode transformer is comprised of two waveguide layers, an upper layer and a lower layer, with the upper layer being contiguous to the lower layer. The lower layer is the integrated optic waveguide layer forming the optical circuit. The input dimensions of the composite two-waveguide structure supports a fundamental mode that accepts all of the light present on the optical fiber. The upper waveguide layer is tapered down from an input width to an output width and then terminates in such a way that at the termination substantially all of the input optical power resides in the lower waveguide layer. The two waveguide layer structure is fabricated by deposition and planarization techniques.

Abstract: A hybrid optoelectronic device and method of producing the hybrid device in which the hybrid device includes a substrate with an input region configured to accept input light, a sol-gel glass multimode interference region coupled to and contiguous with the input region and configured to accept and replicate the input light as multiple self-images, and a sol-gel glass output region contiguous with the multimode region and configured to accept and to output the multiple self-images. Alternatively, the hybrid optoelectronic device includes a substrate with a photoelectronic device, a surface resonator including a light-emitting part of the photelectronic device and configured to resonate light from the photoelectronic device to produce a laser light, and a grating outcoupler contiguous with the surface resonator and configured to diffract the laser light outward from the grating outcoupler and to electrically vary an index of refraction of the outcoupler and change a direction of the diffracted laser light.

Abstract: An optical switch includes support devices to create bends in the flexible optical fibers. In accordance with the invention, the support devices may be fabricated to include one or more microelectromechanical system (MEMS) devices. The support devices may also be fabricated as a support plate connected to one or more MEMS devices. A MEMS device includes a pair of actuators, such as electrostatic actuators, to create a bend in a flexible optical fiber. Selectively actuating or rotating the support devices creates bends in the optical fibers, which direct a beam of light from an input optical fiber to a corresponding output optical fiber. The bends in the fibers provide maximum coupling of the light into an output fiber.

Abstract: A device for converting frequency of electromagnetic radiation includes a nonlinear medium that forms a moving grating in the nonlinear medium by introducing at opposite ends of the nonlinear medium a first set of electromagnetic radiation having varying frequencies. Electromagnetic radiation is inputted into the nonlinear medium at a first frequency and extracted at a second frequency from the nonlinear medium. The moving grating in the nonlinear medium allows for electromagnetic radiation to be converted into the second frequency.

Abstract: A wavelength conversion device includes a photodetector for generating a photocurrent in response to the detection of radiation at a first wavelength. An avalanche multiplier amplifies the signal photocurrent and feeds this to a light emitting element that produces radiation at a second wavelength shorter than the first wavelength and corresponding to the detected radiation at the first wavelength. The components are assembled together in an integrated stacked arrangement either by epitaxial growth or wafer fusion of the individual components. The device is useful as an image intensifier or thermal imaging device.

Abstract: An apparatus and method is provided which allows transfer of DC electrical power across a transparent or semitransparent medium such as glass. Electrical power transfer is achieved using a suitable optical source (matched visible light or infrared LED or LD arrays are best suited) that illuminates a matched solar cell array on the other side of the medium.

Abstract: An optical fiber having a length of one kilometer or more with average transmission loss at a wavelength of 1383 nm being less than average transmission loss at a wavelength of 1310 nm, wherein a maximum value of a transmission loss at the wavelength of 1383 nm of any one kilometer section along the entire length of the optical fiber does not exceed the average transmission loss at the wavelength of 1383 nm along the entire length of the optical fiber by 0.03 dB/km or more.

Abstract: A high power Doherty amplifier circuit having at least one input terminal and at least one output terminal comprising at least one carrier transistor (30) forming a main amplifier stage; at least one peak transistor (32) forming a peak amplifier stage; a first input line (27) connecting the input terminal (28) to an input (29) of the carrier transistor (30); a second input line (31) connecting the input terminal (28) to an input (63) of the peak transistor (32); a first output line (33) connecting the output terminal (56) to an output (49) of the carrier transistor (30); and a second output line (35) connecting the output terminal (56) to an output (75) of the peak transistor (32).

Abstract: An optical fiber for optical amplification, characterized in that a full width at half maximum of gain spectrum is 45 nm or more; and a maximum value of power conversion efficiency is 80% or more. A method for producing a rare earth element-doped glass for use in manufacturing the optical fiber, which comprises a deposition step of depositing fine silica glass particles and a co-dopant (a) to prepare an aggregate of fine silica glass particles doped with the co-dopant (a); and a immersion step of immersing the aggregate of fine silica glass particles prepared in the deposition step in a solution containing the rare earth element and the co-dopant (b) to thereby dope the aggregate of fine silica glass particles with the rare earth element component and the co-dopant (b).

Abstract: A light guide, a line-illuminating device, and an image-scanning device are provided which are excellent in uniformity of the light amount. A light-reflecting portion comprised of tubular concave surfaces becomes a reflecting surface having tubular convex surfaces when seen from the inside of the light guide. With such structure, even when the incident angle of light from a light source unit slightly displaces, the reflection angle in the tubular convex surfaces significantly changes. In an irregular surface having a triangular shape, as in a conventional example, the incident angle becomes almost uniform in the area far from the light source unit, and thereby the reflection angle also becomes uniform. Consequently, it is difficult to achieve uniform reflection in the main-scanning direction. However, with the tubular concave surfaces, light is reflected uniformly toward the upper surface as a light-emitting surface.

Abstract: An optoelectronic transmitting and/or receiving module and an optical plug include a circuit carrier disposed at least partially in an alignment parallel to the optical axis of the module in a module housing. The circuit carrier forms a tongue-shaped region that protrudes into the continuation. A transmitting device and/or a receiving device is disposed in the continuation, where they are connected to the circuit carrier. The associated axial offsetting of the transmitting device and/or receiving device in the direction of an optical plug to be coupled on permits the provision of plug-in connections with improved protection of the devices and the fiber ends.