Abstract: An exemplary multi quantum well structure may include a silicon platform having a pit formed in the silicon platform, a chip positioned inside the pit, a first waveguide formed in the chip, and a second waveguide formed in the silicon platform. The pit may be defined at least in part by a sidewall and a base. The chip may include a first side and a first recess in the first side. The first side may be defined in part by a first cleaved or diced facet. The first recess may be defined in part by a first etched facet. The first waveguide may be configured to guide an optical beam to pass through the first etched facet. The second waveguide may be configured to guide the optical beam to pass through the sidewall. The second waveguide may be optically aligned with the first waveguide.

Abstract: A gas leak proof corrugated sheath design for reducing friction in an optical fiber cable (100) includes a plurality of ribbons (102) in a plurality of ribbon bundles (104), one or more water swellable yarns (110), a first layer (106), one or more ripcords (108), one or more strength members (112) and a second layer (114). The first layer, surrounding the plurality of ribbon bundles by the second layer having a plurality of ribs (116) and a plurality of grooves (118) to reduce number of contact points between the optical fiber cable and a duct to reduce coefficient of friction between the second layer and an inner surface of the duct.

Abstract: Disclosed embodiments include laser systems. An illustrative laser system includes a tunable laser. A beam splitter is operatively couplable to an output of the laser and is configured to split light output from the laser into a first path and a second path. A first modulator is disposed in the first path and is configured to generate first set of sidebands. A bandpass filter circuit includes a fiber Bragg grating filter and is operatively couplable to receive output from the first modulator and to pass a selected sideband of the first set of sidebands. A lock circuit is disposed in the second path, is configured to determine and stabilize wavelength of the laser, and is further configured to cooperate with the fiber Bragg grating filter to maintain a static lock point for the laser while allowing output of the first path to be tunable with respect to the lock point.

Abstract: An optical waveguide structure comprising a nonlinear optical waveguide, a central region, a first side region, and a second side region. The central region is located within the nonlinear optical waveguide, wherein the central region comprises a nonlinear optical material. The first side region is on a first side of the central region and the second side region is on a second side of the central region. The nonlinear optical material comprising the central region has a first nonlinear coefficient that is larger than a second nonlinear coefficient of a second material comprising the first side region and the second side region.

Abstract: A method of optimizing the coupling to an optical fiber, including: generating a femtosecond laser pulse; directing a focus of the laser pulse to a longitudinal depth in the region beneath the endface of the optical fiber to generate microvoids; adjusting the intensity of the laser pulse at different depths, such that a refractive index profile is created in the region beneath the endface of the optical fiber.

Abstract: A photon source for generating entangled photons includes a pump laser, and 4-N, N-dimethylamino-4?-N?-methyl-stilbazolium-tosylate (DAST) crystals, the pump laser pumping the DAST crystals with pump photons to generate a stream of pairs of entangled photons, each pair comprising a signal photon and an idler photon.

Abstract: In one aspect, a device is disclosed that includes one or more input ports structured to receive a pumping light at a pumping wavelength and a signal light at a signal wavelength, and one or more output ports structured to output light including an amplified signal light at the signal wavelength and a second harmonic idler light. The device includes a nonlinear optical material to mix the pumping light and the signal light and to cause nonlinear conversion of the pumping light into the amplified signal light and generate an idler light at an idler wavelength. The nonlinear optical material is further structured to convert the idler light into the second harmonic idler light which eliminates the idler light at the one or more output ports and prevents back-conversion of the amplified signal light and idler light to the pumping wavelength.

Abstract: An optical assembly may include a waveguide and a Bragg grating configured to couple light into or out of the waveguide. The Bragg grating may include a plurality of layer pairs, wherein at least one layer pair comprises a first material having a first refractive index and a second layer having a second refractive index, and wherein properties of the Bragg grating are selected so that the Bragg grating exhibits a substantially similar diffractive efficiency and diffraction angle for light of at least two colors.

Abstract: An optical fiber combiner comprises a double-clad fiber (DCF) and one or more multimode fibers (MMFs). DCF comprises a transition portion, a first taper portion, and an output section coupling to the first taper portion, whereas each of MMFs comprises a second taper configured to be fused around DCF in the transition portion. MMFs are configured to carry a combined optical energy (COE) and to couple to DCF. COE passes through the second taper with larger divergence of higher-order modes generated and coupled into DCF, whereas the first taper portion can partially offset the larger divergence. COE coupled, when traced through the output section, emerges in air with a smaller output beam divergence of the higher-order modes, thereby preserving some of the higher-order modes in the output section and increasing a coupling efficiency of COE coupled from MMFs to DCF with improved thermal performance.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to non-planar waveguide structures and methods of manufacture. The structure includes: a first waveguide structure; and a non-planar waveguide structure spatially shifted from the first waveguide structure and separated from the first waveguide structure by an insulator material.

Abstract: Object: To provide a remote substance identification device that can identify an unidentified substance, such as a harmful substance, from a remote location. Solution: Provided are a remote substance identification device and method, the device comprising a laser device 10 that emits a laser beam to an irradiated space; a wavelength conversion device 20 that converts a wavelength of the laser beam emitted from the laser device into a plurality of different wavelengths and that emits laser beams of the different wavelengths to the irradiated space; a light collecting-detecting device 30, 40, 50 that collects and detects resonance Raman-scattered light generated from an irradiated object due to resonance Raman scattering; and a processor 60 that identifies the irradiated object on the basis of a result detected by the collecting-detecting device 30, 40, 50.

Abstract: Improved architectures and related methods for enhancing entangled photon generation in optical systems are described. Photons from a light source are coupled from the fundamental mode into an optical resonator in a higher-order mode. The optical resonator comprises a photon generation portion configured to generate entangled photons from the coupled photons. The entangled photons are selectively extracted from the optical resonator in the fundamental mode while the remaining photons propagate through the optical resonator mode and combine with the source photons entering the optical resonator. While the source photons propagating or entering the optical resonator resonate within the optical resonator, the entangled photons are not resonant with the optical resonator, and are selectively extracted before traversing a complete cycle in the optical resonator. Extracted entangled photons can then be output for use in, for example, a communication system.

Abstract: An integrated optical system includes a wavelength tunable optical source and a photonic integrated circuit (PIC). The PIC includes a set of spatial waveguide switches having an input optically coupled to the wavelength tunable optical source and a plurality of outputs. The PIC also includes an optical emitter having a plurality of inputs, each being coupled to a respective one of the plurality of outputs of the set of spatial waveguide switches, the optical emitter configured to produce at an output an optical beam having a wavelength dependent emission direction that changes as light is switched by the set of spatial waveguide switches such that the optical beam may be steered in two dimensions.

Abstract: A device for generating laser pulses is provided, the device having an optical parametric oscillator converts the laser pulses of a pump laser to laser pulses at a signal wavelength and at an idler wavelength. The optical parametric oscillator has an optical resonator with a non-linear wavelength converter. It is an object of the invention to provide a device that makes efficient generation of synchronous laser pulse trains with two different central wavelengths possible. To this end, the invention proposes that the pump laser is tunable with respect to the pump wavelength and the repetition frequency, wherein the resonator has an optical fibre with a dispersion in the range of 10-100 ps/nm and a length of 10-1000 m. The invention furthermore relates to a method for generating laser pulses using such a device.

Abstract: A method and a system for generating intense, ultrashort pulses of XUV and soft X-ray radiation via high-order harmonic generation (HHG), the method comprising selecting a nonlinear solid target and a laser source; separating a beam from the laser source into a first laser beam and a second laser beam; focusing the first laser beam onto the nonlinear solid target, thereby generating a laser ablated plume; and compressing and frequency-doubling the second laser beam and directing a resulting second compressed and frequency-doubled laser beam to the laser ablated plume, thereby yielding high-order harmonic generation of radiation of photon energies in a range between 12 eV and 36 eV.

Abstract: Provided is a connector assembly for optically connecting one or more optical fibers and an array of vertical coupling elements of a photonic integrated circuit (PIC). In various embodiments, the connector assembly is constructed to independently optically scale some feature sizes, such as, for example, the transverse mode size, the array size, the array geometry, and/or various incidence angles, the optical scaling being performed, e.g., from a fiber end face plane to a connector-mating plane and further to a PIC coupling plane. In some embodiments, the connector assembly may support a polarization (de)multiplexing functionality.

Abstract: A pre-terminated end of a fiber optic cable has a protective cap that protects the optical fiber and the ferrule assembly at the terminal end. The protective cap has an attachment feature enabling a pull cord to attach to the protective cap. The protective cap has a body including an exterior surface and a receptacle formed in the body and configured to receive a portion of the fiber optic cable, and the attachment feature. The attachment feature includes a cavity formed in a tip of the body and at least two openings formed in the exterior surface of the body and connected to the cavity.

Abstract: An optical waveguide structure comprises a first coupler and a second coupler that, in combination, direct a first-wavelength light to travel through a nonlinear-optical waveguide, the two couplers and an extension waveguide but not a secondary waveguide, a first resonator loop is defined for which the first-wavelength light is resonant. The two couplers, in combination, also direct a second-wavelength light to travel through the nonlinear-optical waveguide, the two couplers and the secondary waveguide but not the extension waveguide, wherein a different second resonator loop is defined for which the second-wavelength light is resonant.

Abstract: A method for the continuous production of a thin-walled, perforated metal hollow profile with one or more fibre waveguides mounted therein. The method includes supplying of a flat metal strip at a first supply rate to a deforming device, which continuously deforms the metal strip into a metal hollow profile with a slot running in a longitudinal direction. Two opposite edges of the metal strip deformed into the metal hollow profile that lie flush against one another in a contact region extending in the longitudinal direction of the metal hollow profile are continuously welded to one another, drawn off from the welding region and perforated.

Abstract: The present disclosure provides systems and methods for preventing or minimizing optical crosstalk in an optical circuit switch (“OCS”). The OCS may include a collimator lens assembly. The collimator lens assembly may include a lens array defined by a plurality of ports. Each port may include a lenslet and a spacer paired with each lenslet. Crosstalk may occur when light from other ports enter the target port's optical fiber. The collimator lens assembly may include an insert positioned relative to the lenslet. The insert may define an aperture that allows light from the target port to pass through. The insert may prevent a portion of light from adjacent ports from passing through the aperture. The insert may be located between the lenslet and spacer, on the curved surface of the lenslet, or on a plate located at a distance from the front of the lenslet.