Abstract: A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below Th, wherein Th is at least about 50° C., preferably 50° C.<Th<250° C.

Abstract: An augmented reality optical system comprises a waveguide structure that includes a waveguide layer supported by a substrate. An input grating and an output grating reside within the waveguide layer and are laterally spaced apart. Input light from a display is made incident upon the input grating. The input light is coupled into the waveguide layer and travels therein as multiple guided modes to the output grating. The input and output gratings provide phase matching so that the guided modes are coupled out of the waveguide layer by the output grating continuously along the output grating to form output light. Meantime, light from a scene is transmitted perpendicularly through the output grating so that the output light and the light from the scene are combined by the eye of a user to form an augmented reality image.

Abstract: A light emitting device having a light-emitting element, a covering resin covering the light-emitting element, a wavelength converting material contained in the covering resin, and a light diffusing agent contained in the covering resin is provided. The light diffusing agent contains glass particles. A first refractive index n1 of the covering resin at a peak wavelength of a light emitted by the light-emitting element and at 25° C. is in a range of 1.48 to 1.60, a second refractive index n2 of the covering resin at the peak wavelength and at 100° C. is at least 0.0075 lower than the first refractive index n1, and a third refractive index n3 of the light diffusing agent at the peak wavelength and at 25° C. is higher than the first refractive index n1.

Abstract: A method of fabricating polymer modulators includes forming an insulating layer on a platform and depositing and patterning a ground electrode on the insulating layer. A bottom polymer cladding layer, a first blocking layer, a polymer core layer, a second blocking layer, and a top polymer cladding layer are deposited in order. A third blocking layer is deposited on the top cladding layer and patterned to define vias which are used to etch ground openings through the top polymer cladding layer, the second blocking layer, the core layer, the first blocking layer, and the bottom cladding layer to the ground electrode. The openings are filled with electrically conductive material from electrical communication with the ground electrode to a surface of the top polymer cladding layer. The third blocking layer is removed and electrical contacts are formed on the top polymer cladding layer in electrical communication with the electrically conductive material.

Abstract: A broadband light source device (100) for creating broadband light pulses (1) comprises a hollow-core fiber (10) of non-bandgap type including a filling gas and being arranged for creating the broadband light pulses (1) by an optical nonlinear broadening of pump laser pulses (2), wherein the hollow-core fiber (10) has an axial hollow light guiding fiber core (11), which supports core modes of a guided light field, and an inner fiber structure (12), which surrounds the fiber core (11) and which supports transverse wall modes of the guided light field, and a pump laser source device (20) being arranged for creating and providing the pump laser pulses (2) at an input side (13) of the hollow-core fiber (10), wherein the transverse wall modes include a fundamental transverse wall mode and second and higher order transverse wall modes, the broadband light pulses (1) have a core mode spectrum being determined by a fiber length, a fiber core diameter, at least one pump pulse and/or beam parameter of the pump laser pu

Abstract: A three-dimensional photonic integrated structure includes a first semiconductor substrate and a second semiconductor substrate. The first substrate incorporates a first waveguide and the second semiconductor substrate incorporates a second waveguide. An intermediate region located between the two substrates is formed by a one dielectric layer. The second substrate further includes an optical coupler configured for receiving a light signal. The first substrate and dielectric layer form a reflective element located below and opposite the grating coupler in order to reflect at least one part of the light signal.

Abstract: A Mach-Zehnder modulator includes an optical waveguide, first and second arm waveguides, an embedded area, an conductive semiconductor layer, first and second signal upper layers extending over the embedded area and connected to the first and second arm waveguides, a first ground upper layer extending over the embedded area along at least one of the first and the second signal upper layers, a ground lower layer connected to the first ground upper layer and extending through the embedded area along the and second first signal upper layers, and a first conductive upper layer connected to the ground lower layer and extending over the embedded area along at least one of the first and second signal upper layers. The ground lower layer extends between the optical waveguide, the first signal upper layer, and the second signal upper layer.

Abstract: An integrated optofluidic device to illuminate, along an irradiation direction, a fluidic sample containing an object to be analysed, the device comprising: a substrate comprising an entry surface and being made of a material transparent to a light beam incident through the entry surface along the irradiation direction; a microfluidic channel formed in the substrate and having a channel portion intercepting the irradiation direction and extending along a longitudinal axis transverse to the irradiation direction, the microfluidic channel comprising a first flow inlet port for loading a fluidic sample therein, and an elongated lens cavity for an optofluidic cylindrical lens, the cavity being formed in the substrate and being arranged along the beam irradiation direction between the entry surface and the microfluidic channel, wherein the lens cavity is in fluid communication with a lens inlet port for loading a lens fluid.

Abstract: A self-aligned tunable metamaterial is formed as a wire mesh. Self-aligned channel grids are formed in layers in a silicon substrate using deep trench formation and a high-temperature anneal. Vertical wells at the channels may also be etched. This may result in a three-dimensional mesh grid of metal and other material. In another embodiment, metallic beads are deposited at each intersection of the mesh grid, the grid is encased in a rigid medium, and the mesh grid is removed to form an artificial nanocrystal.

Abstract: The present invention provides optical computing by means of fast Fourier transform Integration on Silicon On Insulator chip technology with implementation in the analog and temporal domain. This is done by cascading (N?2) stages of delayed interferometers (couplers and phase shifters) where a parallel set of N time samples are taken and using the delay lines and phase of the optical components (constructive/deconstructive interference) the DFT is computed. The Optical Fast Fourier Transform (OFFT) design was built on passive components (2×2 couplers: cascaded Mach Zehnder Interferometer) used for addition and subtraction through optical interference, waveguides with short path differences are used for phase shifting and waveguides with long path differences are used for signal delay based on the needed number of outputs. Since the OFFT is a system of imbalanced interferometers, there are additional bends designed to compensate for the difference in power ratios of the arms.

Abstract: A microstructured optical fiber includes a core region and a cladding region which surrounds the core region. The cladding region includes a plurality of cladding features within a cladding background material, wherein the cladding region includes an inner cladding region with at least one inner ring of cladding features and an outer cladding region with at least three outer cladding rings of outer cladding features. The inner cladding features have a first characteristic diameter and the outer cladding region includes a plurality of outer cladding features having a characteristic diameter smaller than the first characteristic diameter. The first characteristic diameter is at least about 10% larger than an average diameter of the outer cladding features and the core region has a diameter of at least about 2 ?m.

Abstract: There is provided an optical waveguide apparatus. The optical waveguide apparatus includes: a first clad layer; a core layer formed on the first clad layer; and a second clad layer formed on the first clad layer to cover the core layer. At least one of the first clad layer and the second clad layer includes a fully cured portion and a semi-cured portion.

Abstract: A three-dimensional photonic integrated structure includes a first semiconductor substrate and a second semiconductor substrate. The first substrate incorporates a first waveguide and the second semiconductor substrate incorporates a second waveguide. An intermediate region located between the two substrates is formed by a one dielectric layer. The second substrate further includes an optical coupler configured for receiving a light signal. The first substrate and dielectric layer form a reflective element located below and opposite the grating coupler in order to reflect at least one part of the light signal.

Abstract: Systems and methods for plasmonics enhanced photomixing for generating continuous-wave (CW) frequency-tunable terahertz radiation in accordance with embodiments of the invention are disclosed. A photomixing system configured to generate continuous-wave terahertz frequency signals can include an optical pump configured to generate at least two beams, where the at least two beams are utilized to create a frequency-offset and operate below a 50% duty cycle, where the duty cycle includes an operation cycle and a sleep cycle. The photomixing system can also include a photomixer that includes a radiating element configured to receive the frequency-offset and to generate a terahertz radiation utilizing the received frequency-offset and the radiating element, where the radiating element includes at least one plasmonic contact electrode.

Abstract: The invention relates to a planar-optical element having at least one photonic component, which is arranged in at least one substrate containing or consisting of at least one polymer, wherein the substrate includes at least one first film layer having a first side and an opposite second side and a second film layer having a first side and an opposite second side, wherein the first side of the second film layer is arranged on the second side of the first film layer and at least the second film layer contains nanowires, at least in a subarea. The invention also relates to a corresponding sensor element and a method for the production thereof.

Abstract: The present invention generally relates to the field of fiber optics, and more particularly, to apparatuses, systems, and methods directed towards improving effective modal bandwidth within a fiber optic communication environment. In an embodiment, a multimode optical fiber in accordance with the present invention comprises a core and cladding material system where the refractive indices of the core and cladding are selected to modify the shape of the profile dispersion parameter, y, as a function of wavelength in such a way that the alpha parameter (?-parameter), which defines the refractive index profile, produces negative relative group delays over a broad range of wavelengths. The new shape of the profile dispersion parameter departs from traditional fibers where the profile dispersion parameter monotonically decreases around the selected wavelength that maximizes the effective modal bandwidth (EMB).

Abstract: Optical fiber data communications are described. A comb laser can provide light at a first wavelength and a second wavelength. Using that light, polarization multiplexing circuitry can generate an optical signal having different polarization components and transceivers can transmit the optical signal having the first wavelength and a probe having the second wavelength via an optical fiber. A polarimeter can determine characteristics of the polarization of the probe. Based on the characteristics, a polarization controller can adjust a polarization of the optical signal. The optical signal can then be split into different polarization components.

Abstract: A quantum dot includes a core-shell structure including a core including a first semiconductor nanocrystal and a shell disposed on the core, and including a material at least two different halogens, and the quantum dot does not include cadmium.

Abstract: The present invention discloses a photonic crystal (PhC) all-optical AND-transformation logic gate, which comprises a PhC-structure unit, an optical-switch unit, a wave-absorbing load, a NOT-logic gate and a D-type flip-flop; two intermediate-signal output ports of the optical-switch unit are respectively connected with the intermediate-signal input port and the wave-absorbing load of the PhC-structure unit; a clock-signal CP input port is connected with three-branch waveguide, and three output ports are respectively connected with first clock-signal CP input port of the optical-switch unit, second clock-signal CP input port of the PhC-structure unit and the NOT-logic-gate input port; the NOT-logic-gate output port is connected with third clock-signal CP input port of the D-type flip-flop; the signal-output port of the PhC-structure unit is connected with the D-signal input port of the D-type flip-flop.

Abstract: A super continuum light source includes an input light source having semiconductor diodes generating an input beam having a wavelength shorter than 2.5 microns. Optical amplifiers receive the input beam and form an amplified optical beam having a spectral width. The optical amplifiers may include a cladding-pumped fiber amplifier doped with rare-earth materials. A nonlinear element may include mid-infrared fibers to receive the amplified optical beam and to broaden the spectral width of the received amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam, wherein the output beam is pulsed. At least a portion of the output beam is in a mid-infrared wavelength range between 2 microns and 5 microns and at least a portion of the one or more mid-infrared fibers comprises a ZBLAN fluoride fiber coupled to a chalcogenide fiber.

Abstract: A magneto photonic encoder, in plane, includes a set of periodic structures of magneto photonic crystals for rotating a polarization of a beam of light responsive to a controllable magnetic field as it is transmitted through the periodic structures. The rotated polarization, in cooperation with a non-reciprocal-mode conversion device produces an encoded signal without use of crossed polarizers. Path optics guide the light beam into the periodic structures for polarization rotation and then to direct the modified beam of light into the non-reciprocal-mode conversion device. Depending upon the implementation, the encoded output may serve as display image primitive precursor to produce an image constituent signal.

Abstract: A spectroscopic analysis device for analysis of a sample comprises an input for receiving light from the sample and a photonic integrated circuit. This photonic optical filter comprises one or more tunable bandpass filters arranged to filter the received light. Furthermore, the device comprises a controller that is arranged—to control the one or more tunable bandpass filters, to receive filter results obtained from the one or more tunable bandpass filters, and to provide spectroscopic analysis results based on the received filter results.

Abstract: Disclosed herein is an optical waveguide element that includes a substrate and a waveguide layer formed on the substrate and comprising lithium niobate. The waveguide layer has a slab part having a predetermined thickness and a ridge part protruding from the slab part. The maximum thickness of the slab part is 0.05 times or more and less than 0.4 times a wavelength of a light propagating in the ridge part.

Abstract: Transducers and methods of making the same include a substrate having a cavity with a diameter that supports whispering gallery modes at a frequency of an input signal. A focusing structure in the cavity focuses the electric field of the input signal. A resonator directly under the focusing structure has a crystalline structure that generates an electro-optic effect when exposed to electrical fields. An electric field of the input signal modulates an output signal in the resonator via the electro-optic effect.

Abstract: Presently described is a method for coupling an optical film to a substrate, laminated optical constructions comprising an optical film and an optical coupling layer disposed on a surface layer of the optical film, and coating compositions useful for optical an optical coupling layer. The coating compositions comprise at least 40 wt.-% inorganic nanoparticles having a refractive index of at least 1.85 and a polymeric silane surface treatment.

Abstract: Novel methods and systems for waveguide fabrication and design are disclosed. Designs are described for fabricating ridge, buried and hybrid waveguides by a femtosecond pulsed laser. A laser system may combine a diode bar, a wavelength combiner and a waveguide. The waveguide may convert the electromagnetic radiation of an infrared laser into that the visible-wavelength range.

Abstract: A white light spectroscopy system includes a super continuum light source having an input light source including semiconductor diodes to generate an input beam having a wavelength shorter than 2.5 microns. The light source includes a cladding-pumped fiber optical amplifier to receive the input beam, and a photonic crystal fiber to receive the amplified optical beam to broaden the spectral width to 100 nm or more forming an output beam in the visible wavelength range. The output beam is pulsed with a repetition rate of 1 Megahertz or higher. The system also includes a lens and/or mirror to receive the output beam, to send the output beam to a scanning stage, and to deliver the received output beam to a sample. A detection system includes dispersive optics and narrow band filters followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.

Abstract: One or more light source apparatuses, one or more information acquisition apparatuses and related method(s) are discussed herein. At least one embodiment of a light source apparatus includes a light source that generates first pulsed light and a nonlinear optical medium that generates second pulsed light having a wavelength different from that of the first pulsed light due to incidence of the first pulsed light. The light source may be configured so that the center wavelength of the first pulsed light is variable across the zero dispersion wavelength of the nonlinear optical medium.

Abstract: A method of forming a device for propagating light includes providing a substrate having a semiconductor material; placing an insulating layer on the substrate; providing a recess reaching through the insulating layer and into the substrate; filling the recess at least partially with a filler material; and arranging a waveguide in or on the filler material.

Abstract: The present invention relates to an integrated photonic device comprising a photonic substrate, and an integrated waveguide provided in or on this substrate. The waveguide is adapted for conducting radiation of a predetermined wavelength. The device further comprises a sub-wavelength grating optically connected to the waveguide, which provides a first periodic variation of the refractive index in at least one first spatial direction. The device also comprises a diffracting grating arranged over the sub-wavelength grating for coupling radiation of the predetermined wavelength in and/or out of the integrated waveguide via the sub-wavelength grating. The diffracting grating provides a second periodic variation of the refractive index in at least one second spatial direction. The first periodic variation has a first pitch that is less than half of the predetermined wavelength, while the second periodic variation has a second pitch that is at least half of the predetermined wavelength.

Abstract: There is provided a device for performing an optical function, the device comprising one or more reflectionless potential wells in an array of waveguides; and one or more control solitons injected into the one or more reflectionless potential wells; wherein the one or more potential wells have potential well design parameters comprising a potential well number, and wherein the one or more control solitons have control soliton design parameters comprising a control soliton number and power; and wherein the optical function of the device is set by the potential well design parameters and the control soliton design parameters. There is also provided a method of manufacturing the device.

Abstract: The disclosure provides for writing or introducing waveguide-like structures in transparent polycrystalline ceramics using femtosecond laser pulses. The disclosure further provides for tuning the demarcation of the waveguide-like structures by varying the number of incident pulses per unit area.

Abstract: An optical system includes a tunable semiconductor light emitter that generates an input beam having a wavelength shorter than about 2.5 microns, an optical isolator coupled to the emitter and configured to block reflected light into the emitter, an optical amplifier receiving the input beam and outputting an intermediate beam, and optical fibers receiving the intermediate beam and forming an output beam. A subsystem includes lenses or mirrors that deliver the output beam to a sample. The subsystem may include an Optical Coherence Tomography (OCT) apparatus having a sample arm and a reference arm, the output beam having a temporal duration greater than approximately 30 picoseconds, a repetition rate between continuous wave and Megahertz or higher, and a time averaged intensity less than approximately 50 MW/cm2. The system may also include a light detection system collecting any of the output beam that reflects or transmits from the sample.

Abstract: A dielectric ceramic composition is represented by a general formula “xBi2O3.yZnO.(z-a)Nb2O5.aV2O5”. The variables, “x”, “y”, “z” and “a” in the general formula respectively satisfy the following conditions: 2.90?x?3.10, 1.90?y?2.10, 1.90?z?2.10, and 0.0005?a?0.020.

Abstract: A diagnostic system includes a semiconductor light emitter(s) configured to generate an input beam having a wavelength shorter than about 2.5 microns. An optical amplifier(s) configured to receive a portion of the input beam communicates an intermediate beam to an output end of the optical amplifier. An optical fiber(s) configured to receive a portion of the intermediate beam forms an output beam with an associated wavelength. A subsystem having lenses or mirrors receives a received portion of the output beam and delivers a delivered portion of the output beam to a sample. The delivered portion has a temporal duration greater than approximately 30 picoseconds and a repetition rate between continuous wave and Megahertz or higher. A time averaged intensity of the delivered portion is less than approximately 50 MW/cm2. A light detection system collects and analyzes a fraction of the delivered portion that reflects or transmits from the sample.

Abstract: A silicone product 100, a lighting unit comprising the silicone product and a method of manufacturing a silicone product are provided. The silicone product 100 comprises polymeric material 110, luminescent material 130 and filler particles 120. The polymeric material 110 comprises a material of the group of polysiloxanes. The polymeric material 110 being light transmitting. The luminescent material 130 comprises particles which have at least in one dimension a size in the nanometer range. The luminescent material 130 is configured to absorb light of a first spectral range and to convert a portion of the absorbed light into light of a second spectral range. The filler particles 120 are of a light transmitting inert material. The filler particles 120 are miscible with the luminescent material 130. The filler particles 120 are provided in the polymeric material 110. The particles of luminescent material 130 are distributed along a surface of the filler particles 120.

Abstract: A highly nonlinear optical fiber having an improved stimulated Brillouin scattering threshold is provided. The fiber includes a central core region made substantially from silica doped with aluminum, a trench region surrounding the central core region, and a silica cladding surrounding the trench region. The refractive index profile of the fiber is optimized. A refractive index difference of the central core region relative to the cladding (?n+) is less than 26×10?3, and more preferably at or near 21×10?3. A refractive index difference of the trench region relative to the cladding (?n?) is less than ?5×10?3. The trench region is preferably doped with fluorine. The aluminum doping level of the central core region is preferably less than 14 wt % Al. A fiber doped with aluminum having this refractive index profile exhibits a significantly higher figure of merit (Pth?Leff) than conventional germanium-doped fibers.

Abstract: An electric-pulse-induced-resistance change device (EPIR device) is provided which is a resistance switching device. It has a buffer layer inserted between a first active resistance switching layer and a second active resistance switching layer, with both active switching layers connected to electrode layers directly or through additional buffer layers between the active resistance switching layers and the electrodes. This device in its simplest form has the structure: electrode-active layer-buffer layer-active layer-electrode. The second active resistance switching layer may, in the alternative, be an ion donating layer, such that the structure becomes: electrode-active layer-buffer layer-ion donating layer-electrode. The EPIR device is constructed to mitigate the retention challenge.

Abstract: A polarizing splitter includes a base, an asymmetric Y-shaped waveguide, and a pair of strip-shaped electrodes. The Y-shaped waveguide protrudes from the upper surface and includes an input section for the passage of both transverse electric and transverse magnetic waves, a first branch for transmitting the transverse electric wave only, and a second branch for transmitting the transverse magnetic wave only. The first branch and the second branch branch from the input section. The electrodes are positioned on the surface, arranged at opposite sides of the input section, and are substantially parallel with a central axis of the input section.

Abstract: In a laser (12, 18) with a laser resonator (13), the laser resonator (13) has a non-linear optical loop mirror (1, 1?), NOLM, which is adapted to guide counter-propagating portions of laser pulses, and to bring the counter-propagating portions of laser pulses into interference with each other at an exit point (4) of the NOLM (1, 1?). The non-linear optical loop mirror (1, 1?) contains a non-reciprocal optical element (7, 7?) on a linear section of the NOLM. In addition to the NOLM, the laser resonator (13) has a linear cavity section. The linear section of the NOLM and the linear cavity section (19) are reassembled on a microoptical bench (112) or within a cylindrical carrier (112).

Abstract: A waveguide coupler includes a first waveguide and a second waveguide. The waveguide coupler also includes a connecting waveguide disposed between the first waveguide and the second waveguide. The connecting waveguide includes a first material having a first index of refraction and a second material having a second index of refraction higher than the first index of refraction.

Abstract: A waveguide is configured to couple light from a light source at a fundamental transverse electric (TE) mode. A mode converter outputs the light to an output region of the waveguide at a higher-order TE mode. A plasmonic transducer receives the light at the higher order TE mode and generates surface plasmons that heat a recording medium. The plasmonic transducer includes: an input end proximate the output region of the waveguide and comprising a first convex curved edge; an output end proximate a surface that faces the recording medium, the output end comprising a second convex curved edge and a peg; and linear edges between the first and second convex curved edges.

Abstract: In a dual speed passive optical network, an optical line termination (OLT) transmits a communication signal having a 10-Gb/s partition and a 2.5-Gb/s partition. The 10-Gb/s partition includes a 10 G data signal and a 2.5 G clock signal so that the PLL of a 2.5 G (legacy) optical network termination (ONT) can remain locked while a 10 G ONT is receiving data. The 2.5 G clock signal includes 1-bit spike signals of greater amplitude than the 10 G data signal.

Abstract: A method of generating a supercontinuum in chalcogenide fiber with a pump light comprising a short pulse fiber laser or diode laser operating with a wavelength of 1.0 ?m or greater that is wavelength shifted through a nonlinear fiber one or more times and amplified one or more times and launched into a chalcogenide fiber whereby the spectrum is broadened in the chalcogenide fiber through various nonlinear processes to generate a supercontinuum within the mid-IR from 1.5 to greater than 5 ?m.

Abstract: This invention describes a photonic sensing method and device based on the periodic dielectric structures of photonic forbidden band, in which the sensing process is carried out through the measurement of variation in signal amplitude as it exits the device. The variation in amplitude is due to a variation in the refraction index of the structure, as a consequence of the presence of the substances that are the object of the sensing. Among the advantages provided by the invention, it is worth mentioning its simplicity in the sensing process; its high level of integration, allowing for a design of reduced proportions; and its adaptability to dielectric structures of one, two or three dimensions.

Abstract: A method of spectrally broadening light pulses includes the steps of providing the light pulses with a laser source, said light pulses having a pulse duration below 1 ps, in-coupling the light pulses into a hollow optical waveguide device, and spectrally broadening the light pulses propagating along the pulse guiding medium by subjecting them to a Raman nonlinearity via excitation of a Raman polarization having a first Raman period, wherein the optical waveguide device subjects the light pulses to anomalous group velocity dispersion which combines with the spectral broadening of the light pulses to result in a Raman-enhanced self-compression of the light pulses, and the light pulses further propagate along the optical waveguide device such that the Raman-enhanced self compression results in a further excitation of a Raman polarization having a second Raman period which is faster than the first Raman period.

Abstract: A logic gate is disclosed having a photonic or polaritonic band gap medium and a plurality of nano particles, atoms or artificial atoms are disposed in the band gap medium. Two coupled electromagnetic pulses are propagated within the medium and produce two output pulses. The output pulses are detected or sensed and a third external electronic field controls the relative velocities of the two output pulses. A method for producing a time delay of an electromagnetic pulse is also disclosed.

Abstract: The invention is a THz waveguide source (3) having a core (9) of great nonlinear coefficient and of a great absorption. The source (3) is adapted to behave as a waveguide in pumping and also in THz range. The THz waveguide source (3) has a cladding of smaller absorption coefficient in the THz range than that of the core. The solution according to the invention diminishes the influence of absorption, while enhances efficiency of generating THz radiation. The waveguide structure and the tilted pulse front excitation together results a greater interaction length and thus a greater THz generating efficiency. According to the solution of the invention highly efficient compact THz waveguide sources can be realized.

Abstract: An illumination system is disclosed for providing dual-excitation wavelength illumination for non-linear optical microscopy and micro-spectroscopy. The illumination system includes a laser system, an optical splitting means, a frequency shifting system, and a picosecond amplifier system. The laser system includes a laser for providing a first train of pulses at a center optical frequency ?1. The optical splitting means divides the first train of pulses at the center optical frequency ?1 into two trains of pulses. The frequency shifting system shifts the optical frequency of one of the two trains of pulses to provide a frequency shifted train of pulses. The picosecond amplifier system amplifies the frequency shifted train of pulses to provide an amplified frequency-shifted train of pulses having a pulse duration of at least 0.5 picoseconds.

Abstract: An optical frequency-division multiplexer includes: a first optical coupler configured to receive a first wavelength-division multiplexed light obtained by wavelength-division multiplexing a first carrier light and a first monitor light and split the first carrier light and the first monitor light from each other; an optical modulator configured to optically modulate the split first carrier light using a signal including a first data signal so as to multiplex the first data signal with the first carrier light; a receiver configured to receive a branched part of the split first monitor light and demodulate a second data signal from the first monitor light; and a second optical coupler configured to couple a remaining part of the split first monitor light and the first carrier light with which the first data signal has been multiplexed.