Abstract: In one aspect, nanoplasmonic devices are described herein. In some embodiments, a nanoplasmonic device comprises a radiation transmissive substrate, a metal layer positioned on the substrate and at least one aperture extending through the metal layer to the radiation transmissive substrate, wherein width of the aperture decreases with increasing depth of the aperture.

Abstract: A light source for high power coherent light can include multiparticle relativistic bunches of electrons generating high intensity propagating fields. Coherent emission between electrons may also be utilized. The source may be independent of any medium or media to remove all constraints on the wavelength of the light emitted. And at least a portion of a single alternating magnetic field for accelerating the electron bunches can be included. The color or wavelength of the produced light can be determined solely by the parameters of the electron bunches and the alternating field. The source can be used for imaging, such as medical imaging or for security, including concealed weapons, and for quality control.

Abstract: A surface treatment agent including a compound represented by the following general formula (P-1) and an acid. In the formula, R1 represents a linear or branched alkyl group having 8 or more carbon atoms, a linear or branched fluorinated alkyl group having 8 or more carbon atoms, or an aromatic hydrocarbon group; R2 and R3 each independently represents a hydrogen atom, a linear or branched alkyl group having 8 or more carbon atoms, a linear or branched fluorinated alkyl group having 8 or more carbon atoms, or an aromatic hydrocarbon group R1—P(?O)(OR2)(OR3)??(P-1).

Abstract: The present invention relates to the use of a substrate for enhancing the fluorescence of a fluorescent molecule, wherein the substrate comprises a solid polymer carrier having a plurality of recesses separated from each other and wherein the solid carrier is coated at least in part by a metal.

Abstract: An imaging device and method are provided. Light from an object is provided as a plurality of sets of light beams to a phase difference array having a plurality of elements. The phase difference array is configured to provide different optical paths for light included within at least some of a plurality of sets of light beams. The light from the phase difference array is received at an imaging element array. The imaging element array includes a plurality of imaging elements. Information obtained from hyperspectral imaging data based on output signals of the imaging element array can be displayed.

Abstract: Disclosed are passive reflector radio communications systems, such as for UHF frequencies or greater than UHF frequencies, and related deployment systems and devices that provide underground communications. Embodiments of the system include reflector elements to provide passive radio communications, structural frameworks to support and orient the reflector elements, methods for calculating reflector size, shape, and position corresponding to a desired wavelength, and deployment methods and devices to install the communication system at a desired location. The passive reflectors can be placed in a folded or otherwise compact mode, for transport into underground tunnels. Once at the desired installation location, the system can be installed, with the reflectors positioned appropriately for the radio frequencies used at the location.

Abstract: A wavelength tunable laser device includes a gain element that provides optical gain. A laser cavity includes at least two cavities, wherein each of the at least two cavities has a different optical cavity length. At least two optical modulators are positioned in the laser cavity, wherein the at least two optical modulators are driven with waveforms so as to tune a wavelength of the wavelength tunable laser device.

Abstract: Provided is a device for modulating or switching an optical signal, comprising a first ring waveguide made of a first material with at least one p-n or p-i-n junction, and a second ring waveguide arranged axially opposite the first ring waveguide. The second ring waveguide is made of a second material that has a thermo-optic coefficient lower than the thermo-optic coefficient of the first material. The first ring waveguide is a sub-wavelength network.

Abstract: Systems and methods provide a nonreciprocal nanophotonic modulator. In some examples, the modulator utilizes acoustic pumping, instead of optical pumping with lasers, and is capable of achieving GHz bandwidth.

Abstract: Disclosed a photonic motor that comprises a first optical waveguides arrangement, including at least one first optical resonator lying in a first plane and forming a static part of the motor; at least a second optical waveguides arrangement, including at least one second optical resonator lying in a second plane parallel to the first plane and forming a moving part of the motor, wherein an evanescent-wave coupling of optical modes is established between at least one first optical resonator of the first optical waveguides arrangement and at least one second optical resonator of the second optical waveguides arrangement, the first and second optical resonator being adapted to guide at least one resonant symmetric mode at a predetermined first wavelength or at least one resonant anti-symmetric mode at a predetermined second wavelength or at least a combination or superposition of at least one resonant symmetric mode at a predetermined first wavelength.

Abstract: A laser system including a seed laser and an optical amplification subsystem, receiving an output of the seed laser and providing an amplified laser output, the optical amplification subsystem including a first plurality of amplifier assemblies, each of the first plurality of amplifier assemblies including a second plurality of optical amplifiers, and phase control circuitry including phase modulating functionality associated with each of the first plurality of amplifier assemblies.

Abstract: An optical amplifying element includes: a pair of reflectors that constitutes a cavity; an active layer disposed between the pair of reflectors; and an excitation unit configured to excite the active layer, wherein the active layer excited by the excitation unit amplifies intensity of a laser beam that enters the optical amplifying element when the laser beam reflects back and forth within the cavity, and wherein the pair of reflectors is configured to change a length of the cavity according to a wavelength of the laser beam.

Abstract: Apparatus (10) for an optical communications network has optical paths for optical traffic, and optical ports (20,40), one of which is an unused input port (20). A security monitoring system (30) has a blocking part (50) comprising an interface (51) coupled removably to the unused input port (20) to occupy it to prevent unauthorized access. A light source is optically coupled to the interface (51) such that, when the interface is coupled to the unused input port, light can be transmitted through the interface (51) into the unused input port (20). An optical detector (60) can detect light reflected back from the interface (51), and there is alarm circuitry (70) configured to output an alarm signal based on the detecting of the reflected light. This monitoring can help make the node more secure from interference such as the introduction of a noise signal. The system can be passive or active, and does not require a change in the installed node configuration and so can be added easily to existing infrastructure.

Abstract: An example laser apparatus of the disclosure may include an oscillator capable of outputting a laser beam, a slab optical amplifier capable of amplifying the laser beam outputted by the oscillator by passing the laser beam through an optical amplification region shaped like a slab and outputting the amplified laser beam, and a mirror disposed on an optical path of the laser beam to enter the slab optical amplifier or the amplified laser beam outputted from the slab optical amplifier, the mirror being movable in a direction parallel to a plane where the laser beam travels in the slab optical amplifier.

Abstract: A handshake synchronization restoration method and system based on visible light communication are provided. The method includes: after a transmitting end in which a state machine varies with unit time is powered on again, transmitting in the form of a visible light signal, to a receive and control system, a status reset signal which varies with unit time, wherein the receive and control system comprises one or multiple receiving ends; and receiving, by the receive and control system, the visible light signal, and when it is determined that the received visible light signal is a status reset signal, adjusting status of a state machine of a receiving end to a state indicated by the status reset signal. Status synchronization with the transmitting end is restored, avoiding a case in which the transmitting end is asynchronous with the receiving end after encountering power outage and being powered on again.

Abstract: A gas laser oscillation apparatus of orthogonal excitation type includes an electric discharge region having a pair of electric discharge electrodes, an axial flow blower having a plurality of rotor vanes and working by a permanent magnet motor, a first heat exchanger having a plurality of cooling fins, the cooling fins arranged on a plane perpendicular to an optical axis, a second heat exchanger having a plurality of cooling fins, the cooling fins arranged on a plane perpendicular to the optical axis, a gas duct having a gas passageway and arranged between the electric discharge region and the first heat exchanger, the axial flow blower being arranged on the gas passageway. The axial flow blower is arranged on a windward side of the first heat exchanger. The second heat exchanger is arranged on a windward side of the axial flow blower.

Abstract: Devices, methods, and systems for cavity-enhanced spectroscopy are described herein. One system includes an optical frequency comb (OFC) coupled to a laser source, and a cavity coupled to the OFC comprising a number of mirrors, wherein at least one of the number of mirrors is coupled to a piezo-transducer configured to alter a position of the at least one of the number of mirrors.

Abstract: An amplifier may include a plurality of discharge tubes arranged in a designed path of a seed laser beam and an optical system arranged to steer the seed laser beam to travel along the designed path.

Abstract: A supercontinuum optical pulse source provides a combined supercontinuum. The supercontinuum optical pulse source comprises one or more seed pulse sources, and first and second optical amplifiers arranged along first and second respective optical paths. The first and second optical amplifiers are configured to amplify one or more optical signals generated by said one or more seed pulse sources. The supercontinuum optical pulse source further comprises a first microstructured light-guiding member arranged along the first optical path and configured to generate supercontinuum light responsive to an optical signal propagating along said first optical path, and a second microstructured light-guiding member arranged along the second optical path and configured to generate supercontinuum light responsive to an optical signal propagating along said second optical path.

Abstract: A method of spatially relaying a first radiation component (1) having a first wavelength and a second radiation component (2) having a second wavelength different from the first radiation component (1), using an optical relaying device (10) which comprises a transparent plate (11) having anti-reflection coatings (12, 13) on both side surfaces thereof, comprises transmitting the first radiation component (1) across the optical relaying device (10) with predetermined incident (a) and emergent angles (?), resp., wherein said anti-reflection coatings (12, 13) being effective for the first radiation component (1) at the incident and emergent angles (?, ?), resp., and reflecting the second radiation component (2) at the optical relaying device (10) with a predetermined reflection angle (a) being equal to at least one of said incident and emergent angles (?, ?), wherein the first and second radiation components (1, 2) are split from each other toward different directions or combined into a common beam path.

Abstract: Described herein are devices and techniques for suppressing parasitic modes in planar waveguide amplifier structures. One or more of the side and end facets of a planar waveguide amplifier are angled with respect to a fast axis defined in a transverse plane perpendicular to a core region. A relationship between glancing in-plane angles of incidence and threshold bevel angles ?T can be used to select side bevel angles ?S to suppress parasitics by redirecting amplified spontaneous emission (ASE) from the core. It is possible to select the one or more bevel angles ?S to be great enough to substantially redirect all but ballistic photons of any guided modes, effectively narrowing a numerical aperture of the planar waveguide amplifier along a slow axis, defined in a transverse plane perpendicular to the fast axis. Beneficially, such improvements can be realized for three part waveguide structures (e.g., cladding-core-cladding), with substantially smooth edge facets.

Abstract: In one aspect a power amplifier comprises a first plurality of laser disks disposed in a first vertical plane and a second plurality of laser disks disposed in a second vertical plane, opposite the first vertical plane, wherein the plurality of laser disks are disposed in a central horizontal plane, and a first plurality of reflecting mirrors disposed in the first vertical plane and a second plurality of reflecting mirrors disposed in the second vertical plane, wherein a first set of reflecting are disposed in a lower horizontal plane and a second set of reflecting mirrors are disposed in an upper horizontal plane, wherein respective laser disks and reflecting mirrors adjacent along an optical axis are positioned to provide a 1:1 imaging system therebetween. Other aspects may be described.

Abstract: The invention relates to a pulsed light source capable of effectively utilizing optical power and selecting the pulse width of output pulsed light. A pulsed light source has a MOPA structure, and comprises a seed light source and an optical fiber amplifier. The seed light source includes a semiconductor laser outputting pulsed light. In the optical fiber amplifier, an optical filter branches pulsed light amplified by a YbDF into a first wavelength component including the peak wavelength and the remaining second wavelength component. An optical switch outputs one of the pulsed light of the first wavelength component and the pulsed light of the second wavelength component which are inputted. Another YbDF amplifies the pulsed light outputted from the optical switch.

Abstract: An apparatus for generating a pulse train with an adjustable time interval is provided. The apparatus, being an annular optical cavity structure, includes a seed source receiving end, a pump source receiving end, an optical coupler, an optical combiner, a gain fiber, an optical path time regulator and a beam splitter. Thus, the apparatus is capable of generating a pulse train with an adjustable time interval to increase material processing quality and speed.

Abstract: A method and apparatus for suppression of stimulated Brillouin scattering (SBS) includes a master oscillator (MO) that generates a beam; a birefringent element that receives and transmits the beam, wherein the beam is transmitted with a transmission delay between two orthogonal axes; a polarization controller that receives the beam and transmits the beam with a desired polarization; a fiber amplifier that receives the beam, amplifies the beam, and transmits a beam; a compensating birefringent element that receives the beam, approximately removes the transmission delay between the two axes of the beam, and transmits an output beam; and a polarization detector that detects the output beam's polarization and provides feedback to the polarization controller to ensure that the polarization of the output beam is approximately equal to a desired output polarization, so as to reduce SBS.

Abstract: A solid-state MOPA includes a mode-locked laser delivering a train of pulses. The pulses are input to a fast E-O shutter, including polarization-rotating elements, polarizing beam-splitters, and a Pockels cell that can be driven alternatively by high voltage (HV) pulses of fixed long and short durations. A multi-pass amplifier follows the E-O shutter. The E-O shutter selects every Nth pulse from the input train and delivers the selected pulses to the multi-pass amplifier. The multi-pass amplifier returns amplified seed-pulses to the E-O shutter. The shutter rejects or transmits the amplified pulses depending on whether the HV-pulse duration is respectively short or long. Transmitted amplified pulses are delivered to a transient amplifier configured for separately suppressing first-pulse over-amplification and residual pulse leakage.

Abstract: Provided is a laser projection apparatus which forms each one frame by performing two-dimensional scanning with laser light and projects images on a screen (201) with blanking periods inserted between frames, the laser light having been outputted from a laser light source (110). The laser projection apparatus is provided with a chive controlling device (132) which, in each of the blanking periods, changes the polarization state of the laser light having been outputted from the laser light source. This configuration enables speckle reduction by having the polarization state changed from one frame to another, and also enables favorable image projection since there is no change in luminance within each one of the frames. Thus, it is made possible to obtain image quality more favorable than that obtained conventionally.

Abstract: The present invention provides an optical amplifying device which can be easily downsized, increased in output, and stabilized. An optical amplifying device 1A includes an optical amplifier 10A and an energy supplier 30. The optical amplifier 10A includes an optical amplifying medium 11 and a transparent medium 12. The energy supplier 30 supplies excitation energy (for example, excitation light) to the optical amplifying medium 11. The optical amplifying medium 11 is supplied with the excitation light to amplify light and output it. To-be-amplified light passes through the transparent medium 12 in the optical amplifying medium 11 a plurality of times. The transparent medium 12 can propagate the to-be-amplified light, for example, zigzag inside.

Abstract: The invention can include an apparatus for producing optical pulses, comprising an oscillator for producing optical pulses at a first optical pulse repetition frequency, the optical pulses having a first frequency of light; a pulse picker for receiving optical pulses having the first optical pulse repetition frequency and operable to reduce the optical pulse repetition frequency to produce optical pulses having the first frequency and a reduced optical pulse repetition frequency that is less than the first optical pulse repetition frequency; an optical fiber receiving optical pulses having the reduced optical pulse repetition frequency and first frequency, to nonlinearly produce light that includes a frequency that is twice the first frequency; and an Ytterbium doped fiber amplifier in optical communication with the pulse picker and the optical fiber and located between the pulse picker and the oscillator.

Abstract: The various laser architectures described herein provide increased gain of optical energy as well as compensation of optical phase distortions in a thin disk gain medium. An optical amplifier presented herein provides for scalable high energy extraction and gains based on a number of passes of the signal beam through a gain medium. Multiple, spatially separate, optical paths may also be passed through the same gain region to provide gain clearing by splitting off a small percentage of an output pulse and sending it back through the amplifier along a slightly different path. By clearing out the residual gain, uniform signal amplitudes can be obtained.

Abstract: A hybrid optical source that provides an optical signal having a wavelength is described. This hybrid optical source includes an edge-coupled optical amplifier (such as a III-V semiconductor optical amplifier) aligned to a semiconductor reflector (such as an etched silicon mirror). The semiconductor reflector efficiently couples (i.e., with low optical loss) light out of the optical amplifier in a direction approximately perpendicular to a plane of the optical amplifier. A corresponding optical coupler (such as a diffraction grating or a mirror) fabricated on a silicon-on-insulator chip efficiently couples the light into a sub-micron silicon-on-insulator optical waveguide. The silicon-on-insulator optical waveguide couples the light to additional photonic elements (including a reflector) to complete the hybrid optical source.

Abstract: Raman signal amplification apparatus comprises an ellipsoidal reflector providing a first real focus f1, and second real or virtual focus f2, both foci being situated within a sample volume. When an input laser excitation beam having an initial numerical aperture (NA) is focused onto one of the foci, the beam is reflected by the reflector and refocused onto alternating foci, such that the NA of the reflected optical path progressively increases for higher efficiency collection of Raman emissions from the multiple foci. The ellipsoidal reflector may be a half section providing a single real focus f1, with a flat reflector producing a mirror image of the ellipsoidal reflector, such that f2 is a virtual focus occupying the same point as f1. Alternatively, the ellipsoidal reflector may have a first half section with a first real focus f1 and a second half section with a second real focus f2.

Abstract: A micro-optical element includes a resonator substrate, at least one microresonator includes a rotationally symmetrical body mounted on the resonator substrate, and a light-reflecting element including a ring-shaped mirror that surrounds the rotationally symmetrical body.

Abstract: Embodiments of the present invention are generally related to a fiber assembly, for example, in a chirped pulse amplification system, for all-fiber delivery of high energy femtosecond pulses. More specifically, embodiments of the present invention relate to a system and method for improving dispersion management when using hollow core photonic bandgap fibers for pulse compression. In one embodiment of the present invention, a fiber assembly comprises: an optical laser oscillator; a first fiber section for stretching the pulses from the laser oscillator, the first fiber section comprising a high order mode fiber; and a second fiber section for compressing the stretched pulses, connected to the first fiber section via a splice, the second fiber section comprising a hollow core photonic bandgap fiber; wherein the fiber assembly outputs a pulse compression at less than 200 fs.

Abstract: A pulsed laser system includes a variable attenuator located in a secondary optical path bounded by a target surface and one or more reflective surfaces outside of the primary laser oscillator of the laser system. The variable attenuator isolates an output optical amplifier of the laser system from light reflected from the target during time periods between laser pulses. In some embodiments, the variable attenuator is synchronously controlled with the primary laser oscillator. In some other embodiments, the variable attenuator is controlled separately from the primary laser oscillator to shape the generated laser pulses.

Abstract: The invention can include an apparatus for producing optical pulses, comprising an oscillator for producing optical pulses at a first optical pulse repetition frequency, the optical pulses having a first wavelength and a first time duration; a pulse picker for receiving optical pulses having the first optical pulse repetition frequency, first wavelength and first time duration and operable to reduce the optical pulse repetition frequency to produce optical pulses having the first wavelength, first time duration and a reduced optical pulse repetition frequency that is less than the first optical pulse repetition frequency; an optical fiber receiving optical pulses at the reduced optical pulse repetition frequency and having the first wavelength and first time duration to produce, at the reduced optical pulse frequency, optical pulses that include one or more nonlinearly produced wavelengths different than the first wavelength.

Abstract: A wavelength-tunable laser system includes an optical fiber collimator array having at least two ports, an optical amplifier connected to one port of an optical fiber, an optical coupler for coupling light incident from the optical amplifier and transmitting the coupled light to another port, a diffraction grating plate for guiding each wavelength component of light incident from the optical fiber collimator array in a different direction, and an Opto-Very Large Scale Integration (Opto-VLSI) processor.

Abstract: A laser and amplifier combination delivers a sequence of optical pulses at a predetermined pulse-repetition frequency PRF. An interferometer generates a signal representative of the carrier-envelope phase (CEP) of the pulses at intervals corresponding to the PRF. The signal includes frequency components from DC to the PRF. The signal is divided into high and low frequency ranges. The high and low frequency ranges are sent to independent high frequency and low frequency control electronics, which drive respectively a high-frequency CEP controller and a low frequency controller for stabilizing the CEP of pulses in the sequence.

Abstract: An amplification apparatus includes: a circulator to receive, at a first terminal, first signal light transmitted from OLT to ONU and first light having a predetermined wavelength different from the first signal light and, at a third terminal, second signal light transmitted from ONU to OLT and second light having the predetermined wavelength; a first reflector to output reflected light back to a second terminal; a first optical amplifier to have an amplification band characteristic of amplifying at least the first signal light; a second reflector to output reflected light back to a fourth terminal; a second optical amplifier to have an amplification band characteristic of amplifying the second signal light without amplifying the second light having the predetermined wavelength; and a first partial reflector to have a wavelength transmission characteristic of outputting the light having a wavelength different from the predetermined wavelength to the second optical amplifier.

Abstract: The various laser architectures described herein provide increased gain of optical energy as well as compensation of optical phase distortions in a thin disk gain medium. An optical amplifier presented herein provides for scalable high energy extraction and gains based on a number of passes of the signal beam through a gain medium. Multiple, spatially separate, optical paths may also be passed through the same gain region to provide gain clearing by splitting off a small percentage of an output pulse and sending it back through the amplifier along a slightly different path. By clearing out the residual gain, uniform signal amplitudes can be obtained.

Abstract: The present invention is related to an imaging metamaterial, comprising at least one resonant unit with a controllable split structure that comprises at least one gap and at least one segment, wherein the segment is connected by a node or separated by the gap. The present invention also provides a method for preparing an imaging metamaterial. The present invention further provides an imaging apparatus.

Abstract: The invention can include an apparatus for producing optical pulses, comprising an oscillator for producing optical pulses at a first optical pulse repetition frequency, the optical pulses having a first wavelength; a first optical fiber amplifier; a second optical fiber amplifier; a pulse picker located between the first and second optical fiber amplifiers, the pulse picker operable to reduce the optical pulse repetition frequency of optical pulses, wherein the first amplifier amplifies optical pulses at the first optical pulse repetition frequency and the second amplifier amplifies optical pulses at a reduced optical pulse repetition frequency that is less than the first optical pulse repetition frequency; a nonlinear optical fiber receiving amplified optical pulses having the reduced optical pulse repetition frequency and the first wavelength to produce, at the reduced optical pulse frequency, optical pulses that include one or more nonlinearly produced wavelengths different than the first wavelength; and

Abstract: The invention relates to optical system including light sources that amplify light using a gain medium. Systems and method of the invention are provided for amplifying light while inhibiting reflections at a peak gain of the gain medium, thereby suppressing parasitic lasing. This allows a system to use a broad range of wavelengths without parasitic lasing, thereby increasing the useable range of a tunable optical filter. In this manner, light at wavelengths not at a peak gain can be used effectively, and the gain medium of an optical amplifier does not limit use of a system to a narrow range of wavelengths associated with a peak gain of the gain medium. A single optical system according to the invention can thus be used for applications that require a broad range of wavelengths.

Abstract: A main amplifier system includes a first reflector operable to receive input light through a first aperture and direct the input light along an optical path. The input light is characterized by a first polarization. The main amplifier system also includes a first polarizer operable to reflect light characterized by the first polarization state. The main amplifier system further includes a first and second set of amplifier modules. Each of the first and second set of amplifier modules includes an entrance window, a quarter wave plate, a plurality of amplifier slablets arrayed substantially parallel to each other, and an exit window. The main amplifier system additionally includes a set of mirrors operable to reflect light exiting the first set of amplifier modules to enter the second set of amplifier modules and a second polarizer operable to reflect light characterized by a second polarization state.

Abstract: Provided is a laser oscillation apparatus capable of stabilizing resonance even when finesse of an optical resonator is increased and generating stronger laser light than that of a traditional apparatus by accumulating laser light in the optical resonator.

Abstract: The various laser architectures described herein provide increased gain of optical energy as well as compensation of optical phase distortions in a thin disk gain medium. An optical amplifier presented herein provides for scalable high energy extraction and gains based on a number of passes of the signal beam through a gain medium. Multiple, spatially separate, optical paths may also be passed through the same gain region to provide gain clearing by splitting off a small percentage of an output pulse and sending it back through the amplifier along a slightly different path. By clearing out the residual gain, uniform signal amplitudes can be obtained.

Abstract: An enhancement cavity includes a plurality of focusing mirrors, at least one of which defines a central aperture having a diameter greater than 1 mm. The mirrors are configured to form an optical pathway for closed reflection and transmission of the optical pulse within the enhancement cavity. Ring-shaped optical pulses having a peak intensity at a radius greater than 0.5 mm from a central axis are directed into the enhancement cavity. Accordingly, the peak intensity of the optical pulse is distributed so as to circumscribe the central apertures in the apertured mirrors, and the mirrors are structured to focus the pulse about the aperture toward a central spot area where the pulse is focused to a high intensity.

Abstract: A method of spatially relaying a first radiation component (1) having a first wavelength and a second radiation component (2) having a second wavelength different from the first radiation component (1), using an optical relaying device (10) which comprises a transparent plate (11) having anti-reflection coatings (12, 13) on both side surfaces thereof, comprises transmitting the first radiation component (1) across the optical relaying device (10) with predetermined incident (a) and emergent angles (?), resp., wherein said anti-reflection coatings (12, 13) being effective for the first radiation component (1) at the incident and emergent angles (?, ?), resp., and reflecting the second radiation component (2) at the optical relaying device (10) with a predetermined reflection angle (a) being equal to at least one of said incident and emergent angles (?, ?), wherein the first and second radiation components (1, 2) are split from each other toward different directions or combined into a common beam path.

Abstract: A laser source includes a laser beam generating section for generating a laser beam in a cavity between first reflector and a second reflector; and a tap section provided in the cavity to take out a part of the laser beam. The laser source is a waveguide-based laser source.

Abstract: Configurations for in-situ gas detection are provided, and include miniaturized photonic devices, low-optical-loss, guided-wave structures and state-selective adsorption coatings. High quality factor semiconductor resonators have been demonstrated in different configurations, such as micro-disks, micro-rings, micro-toroids, and photonic crystals with the properties of very narrow NIR transmission bands and sensitivity up to 10?9 (change in complex refractive index). The devices are therefore highly sensitive to changes in optical properties to the device parameters and can be tunable to the absorption of the chemical species of interest. Appropriate coatings applied to the device enhance state-specific molecular detection.