Abstract: A system includes a high energy laser (HEL) configured to transmit a HEL beam and a beacon illumination laser (BIL) configured to transmit a BIL beam. The system also includes at least one fast steering mirror (FSM) configured to steer the BIL beam to be offset from the HEL beam. The system further includes at least one Coudé path FSM configured to correct for atmospheric jitter of the HEL beam and the BIL beam while maintaining the offset of the BIL beam from the HEL beam.

Abstract: Techniques for extending distributed acoustic sensing (DAS) range in undersea optical cables are provided. For example, DAS range can be extended by transmitting and amplifying a DAS signal along multiple spans of a first optical fiber, routing or bypassing the DAS signal from the first optical fiber to a second optical fiber different from the first fiber via a high-loss loopback architecture, and returning and amplifying the DAS signal along the same multiple spans back to a DAS device. The DAS device may then receive and process the DAS signal to detect any changes in the DAS environment. The loopback configuration may be based on different types of loopback architecture.

Abstract: Provided is an optical modulator manufacturing method capable of determining the quality of an optical modulator having MMI waveguides and realizing improvement in yield during manufacturing. Here, in waveguide fabrication processes, hard mask material deposition, soft mask material application, exposure, and hard mask fabrication are executed, and then in hard mask width length measurement, the hard mask width for fabricating the MMI waveguide is measured at one or more locations. In hard mask width quality determination based on machine learning results, the quality of optical characteristics of the chip is predicted and determined in advance, based on sample data created in advance by analyzing a relationship between the hard mask width and optical characteristics of the optical modulator, depending on whether the hard mask width is present in a permissible range of the sample data. Depending on the result of the above-mentioned determination.

Abstract: A DAS system may include an OTDR, and acoustic-sensing optical fibers coupled to the OTDR. The acoustic-sensing optical fibers may have known relative positions within an acoustic wave transmitting medium. The DAS system may also include a processor cooperating with the OTDR to determine a propagation direction of an acoustic wave from an acoustic event in the acoustic wave transmitting medium based upon the known relative positions of the acoustic-sensing optical fibers.

Abstract: A light guide includes a first and second transparent monolithic optical parts (TMOP). The first TMOP has a first surface having two sets with one flat surface followed by one prism array. Each flat surface has a partially-reflective coating, and the first TMOP has a flat opposite second surface. Each prism array has two prisms having a first and a second surfaces which are oblique to each other and to the first TMOP's opposite second surface. The prism arrays first surfaces have a partially-reflective coating. The second TMOP has a first surface with a geometrically complementary shape relative to the shape of the first TMOP's first surface, and has a flat opposite second surface. The first and second TMOPs are assembled together using an optically transparent adhesive material, such that the second surfaces of the first and second TMOP of the light guide assembly are parallel to each other.

Abstract: A near-field probe (and associated method) compatible with near-infrared electromagnetic radiation and high temperature applications above 300° C. (or 500° C. in some applications) includes an optical waveguide and a photonic thermal emitting structure comprising a near-field thermally emissive material coupled to or part of the optical waveguide. The photonic thermal emitting structure is structured and configured to emit near-field energy responsive to at least one environmental parameter of interest, and the near-field probe is structured and configured to enable extraction of the near-field energy to a far-field by coupling the near-field energy into one or more guided modes of the optical waveguide.

Abstract: A system includes an optical waveguide, provided as a component of a first part, and at least one sensor system, provided as a component of a second part. The second part is movable relative to the first part, and the optical waveguide radiates light laterally on the side. The sensor system detects the light intensity of the laterally emitted light emitted by the optical waveguide. A grating is provided between the sensor system and the optical waveguide.

Abstract: Aspects of the disclosure are drawn to methods for producing a fused connector termination. An exemplary method may include setting a specification requirement to be met by the fused connector termination and applying an amount of heat to a proximal region of an unfused connector termination. The proximal region of the unfused connector termination may include an inner optical fiber coaxially positioned within an outer ferrule, and applying the amount of heat may at least partially fuse the optical fiber to the outer ferrule to form an at least partially fused connector termination. The method may also include imaging the proximal region of the at least partially fused connector termination and determining, based on the imaging, whether the proximal region of the at least partially fused connector termination meets the specification.

Abstract: An optical transmission device includes: an IQ optical modulator to modulate incident light with a modulation signal, and adjust a phase of the modulated light with a phase bias, or adjust a phase of the incident light with the phase bias, and modulate the phase adjusted light with the modulation signal, a light intensity detector to detect light intensity of modulated light, a synchronous detection circuit to synchronously detect a light intensity signal and a dither signal, and a bias signal generating unit to monitor a change in amplitude of the modulation signal, generate the bias signal according to the synchronous detection signal when a range of the change is equal to or less than a first threshold, and generate a bias signal maintaining a phase bias before the range of the change becomes larger than the first threshold as the bias signal.

Abstract: An eyepiece waveguide for an augmented reality display system may include an optically transmissive substrate, an input coupling grating (ICG) region, a multi-directional pupil expander (MPE) region, and an exit pupil expander (EPE) region. The ICG region may receive an input beam of light and couple the input beam into the substrate as a guided beam. The MPE region may include a plurality of diffractive features which exhibit periodicity along at least a first axis of periodicity and a second axis of periodicity. The MPE region may be positioned to receive the guided beam from the ICG region and to diffract it in a plurality of directions to create a plurality of diffracted beams. The EPE region may overlap the MPE region and may out couple one or more of the diffracted beams from the optically transmissive substrate as output beams.

Abstract: Configurations for an interferometric device used for multiplexing and de-multiplexing light are disclosed. The interferometric device may include a first input waveguide, a second input waveguide, an interferometric waveguide, and an output waveguide. A fundamental mode of light may be launched into the first and second input waveguides, and the interferometric waveguide may receive the fundamental mode and generate a higher order mode of light, where the two modes of light may be superimposed while propagating through the interferometric waveguide. The two modes of light may be received at an output waveguide that collapses the two modes into a single mode. The light propagating through the interferometric device may be used for increasing optical power even though the wavelengths of light may be different from one another. Additionally, the interferometric device may reduce coherent noise.

Abstract: Systems and methods of dispersion compensation in an optical device are disclosed. A holographic optical element may include a set of different holograms in a grating medium. Each hologram in the set may have a corresponding grating vector with a grating frequency and direction. The directions of the grating vectors may vary as a function of the grating frequency. Different holograms in the set may diffract light in a particular direction so that the light emerges from a boundary of the grating medium in a single given direction regardless of wavelength. A prism may be used to couple light into the grating medium. The prism may be formed using materials having dispersion properties that are similar to the dispersion properties of the grating material. The prism may have an input face that receives perpendicular input light. The prism may include multiple portions having different refractive indices.

Abstract: A fibre endoscope system (100) comprises a catheter (10) with a probe head (10a) for entering into a body cavity (C) adjacent or near a sample region (S). A source fiber (11) has a first fiber ending (11a) and a signal fiber (12) has a second fiber ending (12a) both remote from the probe head (10a) but separate. A sampling fiber (13) has a third fiber ending (13a) disposed at the probe head (10a). A fiber coupler (15) is configured to optically couple at least the source fiber (11) to the sampling fiber (13), and the sampling fiber (13) to the signal fiber (12). A sampling fiber length (L13) of the sampling fiber (13) between a fiber coupler (15) and the third fiber ending (13a) is shorter than a source fiber length (L11) of the source fiber (11) between the fiber coupler (15) and the first fiber ending (11a).

Abstract: A method for manufacturing a circuit board structure with a waveguide is provided. The method includes: providing a first substrate unit, a second substrate unit, a third substrate unit, and two adhesive layers, the first substrate unit including a first dielectric layer and a first conductive layer, the first conductive layer including a first shielding area and two first artificial magnetic conductor areas disposed on two sides of the first shielding area; the second substrate unit including a second dielectric layer and a second conductive layer, the second conductive layer including a second shielding area; the third substrate unit defining a first slot, and the adhesive layer defining a second slot; stacking the first substrate unit, one of the adhesive layers, the third substrate unit, another one of the adhesive layers, and the second substrate unit in that order; pressing the intermediate body.

Abstract: An optical coupling having a coupling part and a mating coupling part which are detachably connected to one another is provided, a connection element being arranged on the coupling part and a fitting mating connection element being arranged on the mating coupling part. These connection elements together form a common optical channel, and the mating connection element is arranged with play in the mating coupling part and without play in the coupling part.

Abstract: Systems and methods of dispersion compensation in an optical device are disclosed. A holographic optical element may include a set of different holograms in a grating medium (704). Each hologram in the set may have a corresponding grating vector (708, 710, 712) with a grating frequency and direction. The directions of the grating vectors may vary as a function of the grating frequency. Different holograms in the set may diffract light in a particular direction so that the light emerges from a boundary of the grating medium in a single given direction regardless of wavelength. A prism (722) is used to couple light into the grating medium. The prism is formed using materials having dispersion properties that are similar to the dispersion properties of the grating material but not indentical. The prism may have an input face that receives perpendicular input light. The prism may include multiple portions having different refractive indices.

Abstract: A system and method for fabricating an optical element. The method includes welding an array of fibers to the optical element, measuring an angle error and a position error of each fiber, calculating a correction for each fiber for the angle error and the position error and correcting the angle and position of each fiber using the calculated corrections.

Abstract: An optical neural network is constructed based on photonic integrated circuits to perform neuromorphic computing. In the optical neural network, matrix multiplication is implemented using one or more optical interference units, which can apply an arbitrary weighting matrix multiplication to an array of input optical signals. Nonlinear activation is realized by an optical nonlinearity unit, which can be based on nonlinear optical effects, such as saturable absorption. These calculations are implemented optically, thereby resulting in high calculation speeds and low power consumption in the optical neural network.

Abstract: An asymmetric adiabatic polarization beam splitter integrated with a waveband filtering splitter unit and a polarization filtering splitter unit is capable of being packaged to form an integrated optical waveguide filtering chip. The waveband filtering splitter unit utilizes an adiabatic optical waveguide structure and stimulated Raman adiabatic passage on an optical waveguide to split the energy of light sources of different bands to different spaces when the light energy is performed with an adiabatic process. The polarization filtering splitter unit utilizes the two orthogonal polarization modes of an optical waveguide with birefringence to achieve a polarization-dependent mode splitting effect based on an adiabatic theory. The asymmetric adiabatic polarization beam splitter realizes the characteristics of integration and high process tolerance, and improves the mass production feasibility.

Abstract: An optical sensor may include a housing, a printed circuit board, an optical emitter, and an optical detector. The housing can define a channel configured to receive a transparent tubing line through which fluid can flow during operation. The housing can have multiple optical pathways, including a primary optical pathway transecting the channel, a light emission optical pathway, and a light detection optical pathway. The optical emitter and optical detector can each be mounted on the printed circuit board. Further, the housing may be positioned on the printed circuit board with the optical emitter aligned to emit light into the light emission optical pathway and the optical detector aligned to receive light from the light detection optical pathway.