Abstract: Provided herein are systems, devices, and methods for improved optical waveguide transmission and alignment in an analytical system. Waveguides in optical analytical systems can exhibit variable and increasing back reflection of single-wavelength illumination over time, thus limiting their effectiveness and reliability. The systems are also subject to optical interference under conditions that have been used to overcome the back reflection. Novel systems and approaches using broadband illumination light with multiple longitudinal modes have been developed to improve optical transmission and analysis in these systems. Novel systems and approaches for the alignment of a target waveguide device and an optical source are also disclosed.

Abstract: A fiber scanning system includes an actuator configured to have an actuator natural frequency, and a fiber optic scanning element coupled to the actuator. The fiber optic scanning element is configured to have a fiber natural frequency that is within a threshold of the actuator natural frequency, such that a displacement gain of the fiber optic scanning element as a function of operating frequency exhibits a first peak value at a first resonance frequency less than the fiber natural frequency, and a second peak value at a second resonance frequency greater than the fiber natural frequency.

Abstract: A nonlinear fiber interferometer is disclosed suitable for fiber sensor and other applications. A first nonlinear fiber section amplifies probe and conjugate sidebands of a pump through four-wave mixing. A second section introduces a phase shift to be measured, for example from a sensor. A third nonlinear fiber section amplifies with phase-sensitive gain to increase signal-to-noise ratio. Based on phase-sensitive output power of probe and/or conjugate components, the phase shift can be measured. Superior performance can be obtained by balancing gain between the (first and third) nonlinear sections. Non-fiber, for example photonic integrated circuit, embodiments are disclosed. Differential sensing, alternative detection schemes, sensing applications, associated methods, and other variations are disclosed.

Abstract: An optical connector member is provided, which includes an optical waveguide retaining portion provided on one of opposite sides of an optical coupling portion and having a cavity for retaining an end portion of an optical waveguide, and an optical fiber retaining portion provided on the other side and having a through-hole for retaining an end portion of an optical fiber. A distal end face of the end portion of the optical waveguide retained in the cavity of the optical waveguide retaining portion and a distal end face of the end portion of the optical fiber retained in the through-hole of the optical fiber retaining portion are positioned in opposed relation to each other in the optical coupling portion with an optical axis of the optical waveguide in alignment with an optical axis of the optical fiber.

Abstract: A planar optical resonator capable of parametrically generating frequency combs includes two optical waveguide cores forming inner and outer loops, the resonator having two sections, in which laterally adjacent segments of the cores are resonantly optically coupled to each other at two separate wavelength regions causing separate peaks in the second order dispersion. The resonator sections may be configured to suppress integrated dispersion of the resonator in a broad spectral range favorably for generating a spectrally uniform frequency comb.

Abstract: A pulsed third-harmonic laser system includes a pulsed laser, an extra-cavity nonlinear crystal, and an intracavity nonlinear crystal. The pulsed laser generates fundamental laser pulses and couples out a portion of each fundamental laser pulse out of the laser resonator to undergo second-harmonic-generation in the extra-cavity nonlinear crystal. Resulting second-harmonic laser pulses are directed back into the laser resonator and mixes with the fundamental laser pulses in the intracavity nonlinear crystal to generate third-harmonic laser pulses. The pulsed third-harmonic laser system thus maintains a non-zero output coupling efficiency regardless of the efficiency of the second-harmonic-generation stage, while the third-harmonic-generation stage benefits from the intracavity power of the fundamental laser pulses.

Abstract: High quality factor electromagnetic metasurfaces are provided. The metasurface is configured to have in plane guided-mode resonances (e.g., corresponding to waveguide modes or the like). Coupling features are included in the metasurface that are configured to couple free-space radiation to the guided mode resonances. The resulting structures have a high-Q response to free-space radiation and can be used for various applications, such as beam splitting, beam steering, and beam focusing or defocusing.

Abstract: Provided is an optical module assembly including: an optical module body in which an optical transceiver is built; a first connector coupled to one side of the optical module body to be connected to an optical transceiver in the optical module body; a second connector, in which an insertion hole for inserting an optical cable is formed and the optical cable is inserted into the insertion hole, connected to the first connector to connect the optical cable to the optical transceiver connected to the first connector; and a disconnection unit installed on the first connector and the second connector to release the connection between the first connector and the second connector by rotation.

Abstract: A multi-core fiber includes: plural cores made of silica-based glass; and a cladding enclosing the plural cores and made of silica-based glass, the cladding having a refractive index lower than a maximum refractive index of the plural cores. Further, the multi-core fiber has a mode field diameter of 5.0 ?m or larger at a wavelength of 1100 nm, the multi-core fiber provides single-mode propagation at the wavelength of 1100 nm, the multi-core fiber has a bending loss of 1 dB/turn or less at the wavelength of 1100 nm when the multi-core fiber is bent at a radius of 2 mm, and the multi-core fiber has a crosstalk between cores of ?30 dB/km or less.

Abstract: An optical fiber includes a core with radius r1, a first clad layer with outermost radius r2 adjacent to the core at radial position r1 and covering the outer periphery of the core, a second clad layer with outermost radius r3 adjacent to the first clad layer at radial position r2 and covering the outer periphery of the first clad layer, and a third clad layer adjacent to the second clad layer at radial position r3 and covering the outer periphery of the second clad layer. The refractive index of the first clad layer decreases continuously from the inside to the outside, reaching a maximum value at radial position r1 and a minimum value at radial position r2. The refractive index of the second clad layer increases continuously from the inside to the outside, reaching a minimum value at radial position r2 and a maximum value at radial position r3.

Abstract: A system for nonlinear frequency conversion includes an acousto-optic modulator for diffracting a portion of an input laser beam as a first-order beam and transmitting a non-diffracted portion of the input laser beam as a zeroth-order beam. The system also includes a nonlinear crystal arranged to receive and frequency convert each of the zeroth-order and first-order beams to generate two respective frequency-converted laser beams, whereby, when the acousto-optic modulator changes the average-power ratio between the zeroth-order and first-order beams, variations of the heat load in the nonlinear crystal are minimized. Either one of the two frequency-converted laser beams may be used as an output laser beam of the system, while the other one of the two frequency-converted laser beams serves to stabilize the heat load in the nonlinear crystal when the acousto-optic modulator is operated to change the average power in the output laser beam.

Abstract: Embodiments include a fiber to photonic chip coupling system including a collimating lens which collimate a light transmitted from a light source and an optical grating including a plurality of grating sections. The system also includes an optical dispersion element which separates the collimated light from the collimating lens into a plurality of light beams and direct each of the plurality of light beams to a respective section of the plurality of grating sections. Each light beam in the plurality of light beams is diffracted from the optical dispersion element at a different wavelength a light beam of the plurality of light beams is directed to a respective section of the plurality of grating sections at a respective incidence angle based on the wavelength of the light beam of the plurality of light beams to provide optimum grating coupling.

Abstract: A hybrid electro-optic (EO) wireline cable includes optical fibers strategically placed within to allow acoustic sensing methods as well as provide power and electrical telemetry. The hybrid EO wireline cable contains optical fibers in the interstices among symmetrically arranged electrical wire bundles to allow a hybrid EO cable to be concurrently used for electrical telemetry and optical fiber sensing without interference in a wellbore environment. This hybrid EO cable maintains electric and magnetic field symmetry which allows an optimal electrical signaling rate through orthogonal propagation modes. By placing optical fibers symmetrically inside the interstitial spaces between electrical wire bundles, the cable maintains its optimal signaling rate and avoids the mechanical and electrical limitations that would be introduced when combining electrical wires and optical fibers in a wireline cable.

Abstract: An optical switch includes a substrate with a waveguide-coupling area and a fluid channel with an anti-wetting layer on a first surface. First and second fluids are on the anti-wetting layer in the fluid channel and at least one fluid is selectively movable relative to the waveguide-fluid coupling area. A fluidic driving mechanism has at least one electrode positioned to apply an electric field to at least one of the fluids in the fluid channel and is capable of moving at least one of the fluids in the fluid channel. The anti-wetting layer has an alkyl silane coating, which includes alkyl silane molecules covalently bonded to the first surface of the fluid channel.

Abstract: Disclosed are ideas to produce an add-on device which turns widely used high repetition rate lasers used for 2-photon microscopy into a light source which can be used for 3-photon microscopy. The add-on encompasses a device to reduce the pulse repetition rate of the high repetition rate (>50 MHz) laser source (laser or OPO) to less than 10 MHz which allows for higher pulse energies while maintaining reasonable average powers. If the high repetition sources operate below 1250 nm the add-on shifts or broadens the seed light to cover 1.3 ?m to 1.8 ?m before amplification. If the high repetition rate source operates at or around 1.3 ?m the add-on only needs to amplify the pulse after downshifting the repetition rate. In another implementation the add-on shifts or broadens the 1.3 ?m light to cover the spectral range out to 1.8 ?m before amplification.

Abstract: A star tracker includes imaging optics comprising a folding mirror, a lens, and a detector. The folding mirror bends light received from an optical axis through the lens that focuses the bent light onto the detector. The star tracker includes a steering mechanism that steers light from an adjustable field of view (FOV) to the optical axis of the imaging optics. The steering mechanism includes: (i) a first photonic crystal element comprising beam pointing spatially variant photonic crystals (SVPCs); (ii) a second photonic crystal element comprising beam pointing SVPCs that is positioned adjacent and axially aligned with the first photonic crystal element; and (iii) a housing that receives the first and second photonic crystal elements for independent rotation.

Abstract: A unitary multi-fiber ferrule has micro-holes for optical fibers, an optical stop plane for the optical fibers, and a plurality of lenses disposed adjacent the front end, each of the plurality of lenses optically aligned with one of the micro-holes and exposed to air. Multiple rows of optical fibers and lenses may also be used in the unitary multi-fiber ferrule. The unitary multi-fiber ferrule requires less processing and equipment than other current optical ferrules.

Abstract: A nonlinear crystal comprising a first end face and an opposing second end face is described. The first and second end faces are separated along an optical axis of the nonlinear crystal by a length in the range of 0.25 mm and 2 mm. Although the length of the nonlinear crystal results in a reduction in the nonlinear effects induced on an optical field propagating through the crystal it also provides for reduced deviation experienced by the generated optical field when the nonlinear crystal is rotated. Therefore, when the nonlinear crystals are incorporated within an enhancement cavity their reduced length allows for the deviation of the output field to be minimised by servo control electronics arranged to adjust a single cavity mirror. This significantly reduces the complexity, and thus expensive of the servo control electronics when compared to those employed with the prior art enhancement cavities.

Abstract: One illustrative device disclosed herein includes a layer of semiconductor material and a first Bragg reflector structure positioned in the layer of semiconductor material, wherein the first Bragg reflector structure comprises a plurality of dielectric elements and a first internal area defined by an innermost of the first plurality of dielectric elements. In this example, the device also includes an optical component positioned above the layer of semiconductor material, wherein at least a portion of the optical component is positioned within a vertical projection of the first internal area.

Abstract: Disclosed is a polarization maintaining connector. The PM connector includes an outer frame, a ferrule structure and an adjustment member. The outer frame forms a main structure of the PM connector. The ferrule structure is provided with a channel for a fiber core to pass through. The ferrule structure is at least partially disposed inside the outer frame and forms a slidable and rotatable connection with the outer frame. The adjustment member forms an axially slidable connection with the ferrule structure and is circumferentially non-rotatable relative to the ferrule structure. The adjustment member is relatively rotatable to the outer frame and has a rotating state and a holding state. The adjustment member keeps relatively rotatable to the outer frame when in the rotating state and keeps relatively secured to the outer frame when in the holding state.