Some embodiments are directed to a multiplexed fiber sensor for a fiber optic hydrophone array, including a signal receiver configured to receive a signal from the fiber optic hydrophone sensor array and an interferometer. The interferometer is configured to produce a first signal component and a second signal component from the signal received from the hydrophone array, and also provided with a first polarisation controller configured to control the polarisation of the first signal component and a second polarisation controller configured to control the polarisation of the second signal component. A modulated carrier signal generator configured to generate a modulated carrier signal component based on the first signal component is also provided. A detector configured to output a demodulated output signal from the modulated signal component and the second signal component is included, wherein the modulated signal component and the second signal component output separately from the interferometer.

An optical element is configured to transmit a light flux emitted from a light source having a single light source wavelength, and is formed from a material in which resin and glass fillers are mixed. A difference between respective refractive index change rates (dn/dT) of the resin and the glass fillers relative to a temperature change at least in a vicinity of the light source wavelength becomes 10.5×10.sup.5 or less.

An optical receptacle includes: an optical receptacle body; two supporters which are connected to a respective end of the optical receptacle body, wherein each supporter is connected to one end of the optical receptacle body at a central portion of the respective supporter, and the two supporters face each other with a space therebetween; and four adhesive reservoirs which are disposed at respective four corners of the optical receptacle in plan view, wherein each of the adhesive reservoirs is a through hole or a recess, and the through hole or the recess is surrounded circumferentially by the supporter. The optical receptacle body and the two supporters together have a plane symmetrical shape with respect to a plane parallel to an optical axis of the light emitted from each of the second optical surfaces. The four adhesive reservoirs are disposed plane symmetrically with respect to the plane.

A plug of a connector that performs optical transmission is provided with an optical connection unit. The optical connection unit includes a lens that is provided on a side surface of the optical connection unit and performs optical connection with a lens provided on an optical connection unit of a receptacle in a direction orthogonal to an inserting/removing direction of the plug, and a locating surface that is provided on the side surface of the optical connection unit and abuts on a locating surface of the receptacle to determine a position of the optical connection unit in a mating condition of the plug into the receptacle.

A system includes a master oscillator configured to generate a low-power optical beam. The system also includes a planar waveguide (PWG) amplifier configured to receive the low-power optical beam and generate a high-power optical beam having a power of at least about ten kilowatts. The PWG amplifier includes a single laser gain medium configured to generate the high-power optical beam. The single laser gain medium can reside within a single amplifier beamline of the system. The master oscillator and the PWG amplifier can be coupled to an optical bench assembly, and the optical bench assembly can include optics configured to route the low-power optical beam to the PWG amplifier and to route the high-power optical beam from the PWG amplifier. The PWG amplifier could include a cartridge that contains the single laser gain medium and a pumphead housing that retains the cartridge.

An optical transmission module includes a light emitting device for transmitting a first optical signal, a light receiving device for receiving a second optical signal, an optical fiber for guiding a third optical signal in which the first optical signal and the second optical signal are coupled, and an optical waveguide substrate having an optical waveguide made of first resin, wherein a groove formed on the optical waveguide substrate is provided with a prism having the optical fiber and a reflective face through which the first optical signal transmit, a first side face of the prism contacts a first wall face of the groove, and a second side face thereof contacts a second wall face of the groove.

An optical transmission module is configured such that: a first optical device is provided on an upper surface of an optical waveguide substrate; a second optical device is provided on a lower surface of the optical waveguide substrate; a V-groove is formed on an end face of the optical waveguide substrate, the V-groove including a first reflective face and a second reflective face as wall faces; the first optical device is optically coupled with an optical waveguide via the first reflective face; and the second optical device is optically coupled with the optical waveguide via the second reflective face.

Embodiments include a silicon photonic chip having a substrate, an optical waveguide on a surface of the substrate and a cavity. The cavity includes an electro-optical component, configured for emitting light perpendicular to said surface and a lens element arranged on top of the electro-optical component. The lens is configured for collimating light emitted by the electro-optical component. The chip also includes a deflector arranged on top of the lens element and configured for deflecting light collimated through the latter toward the optical waveguide. The lens element includes electrical conductors connected to the electro-optical component. The electrical conductors of the lens element may for instance include one or more through vias, one or more bottom electrical lines on a bottom side of the lens element (facing the electro-optical component), and at least one top electrical line.

An optical module includes a lens sheet having one or more lenses, a substrate having a photoelectric conversion device mounted on a first face thereof and having a first penetrating hole formed therethrough between the photoelectric conversion device and the one or more lenses, and an adhesive layer configured to bond a face of the lens sheet to a second face of the substrate, wherein the adhesive layer has a second penetrating hole formed therethrough between the one or more lenses and the photoelectric conversion device, and a pathway is provided to connect a space constituted by the first penetrating hole and the second penetrating hole to an outside of the space.

The invention provides an optical module which is less likely to be damaged, and can be assembled at low cost. The optical module comprises a housing having an electrical signal port for inputting and/or outputting an electrical signal and an optical signal port for inputting and/or outputting an optical signal, a first substrate arranged in the housing so as to connect to the electrical signal port, an optical fiber arranged in the housing so as to connect to the optical signal port, and a second substrate provided with an optical device which connects to the optical fiber to input the optical signal from the optical fiber and output the optical signal to the optical fiber, and arranged in the housing so as to electrically connect to the first substrate, and to be inclined with respect to a base plane of the housing.