Abstract: A short wavelength light source is provided with a fundamental wave light source for generating a fundamental wave, and a plurality of wavelength conversion elements made of nonlinear optical crystals having periodic polarization-inversion structures and adapted to convert a part of the fundamental wave into a second harmonic, and the nonlinear optical crystals of the plurality of wavelength conversion elements are different in material or composition. By converting the fundamental wave from the fundamental wave light source by the plurality of wavelength conversion elements, the generation of a thermal lens effect caused by light absorption can be suppressed to improve a high output resistance.

Abstract: A beryllium borate fluoride salt nonlinear optical crystal is represented by molecule formula Mbe2BO3F2, wherein M is Rb or Cs. The crystal is grown by melt salt method, comprising the following step, mixing beryllium borate fluoride salt with flux at appropriate ratio, rising to 750-800° C., and keeping at constant temperature, then cooling to 2-10° C. higher than saturated temperature to obtain a elevated solution; putting seed crystal on seed crystal pole into the elevated solution, rotating the seed crystal pole, cooling to saturated temperature, and then cooling slowly; raising the obtained crystal above liquid level and cooling to room temperature, then obtaining the present nonlinear optical crystal. The crystal has nonlinear optical effect, broad transmittance wave, adsorption edge of ultraviolet lower to 150 nm, doesn't deliquesce, isn't soluble to diluted hydrochloric acid and nitric acid, and has good chemical resistance.

Abstract: Optical parametric oscillator including a semiconductor microcavity being configured to spatially localize polaritons of at least three quantized polariton energy levels to effect an optical parametric oscillation.

Abstract: Methods and devices for generating stable, tunable and intense output light pulses are provided. A primary beam of light pulses is used to form a filament in an interaction zone. A secondary bean of light pulses is superposed with the filament and interacts therewith to generate the output light pulses. The parameters of the primary and secondary beams in the interaction zone can be controlled to obtain targeted optical characteristics of the output pulses. Multiple secondary beams may also be used.

Abstract: Phase-sensitive amplification (PSA), which is produced by degenerate four-wave mixing (FWM) in a randomly-birefringent fiber, has the potential to improve the performance of optical communication systems. Scalar FWM, which is driven by parallel pumps, is impaired by the generation of pump-pump and pump-signal harmonics, which limit the level, and modify the phase sensitivity, of the signal gain. In contrast, vector FWM, which is driven by perpendicular pumps, is not impaired by the generation of harmonics. Vector FWM produces PSA with the classical properties of a one-mode squeezing transformation.

Abstract: A tunable pulsed laser source comprising a seed source adapted to generate a seed signal and an optical circulator. The optical circulator includes a first port coupled to the seed source, a second port, and a third port. The laser source also includes an amplitude modulator characterized by a first side and a second side. The first side is coupled to the second port of the optical circulator. The laser source further includes a first optical amplifier characterized by an input end and a reflective end including a spectral-domain reflectance filter. The input end is coupled to the second side of the amplitude modulator. Moreover, the laser source includes a second optical amplifier coupled to the third port of the optical circulator.

Abstract: The resolution obtained by an imaging system utilizing separable photons can be achieved by an imaging system making use of entangled photons. Since resolution is not being increased from the separable-photon system, the imaging system utilizing entangled photons can take advantage of a smaller aperture. This results in a smaller and lighter system, which can be especially valuable in satellite imaging where weight and size play a vital role.

Abstract: A method and an apparatus for generating a terahertz wave, wherein one end face 12a of a non-linear optical crystal 12 is positioned approximately orthogonally to a direction of generation of a terahertz wave 4, pump light 2 and idler light 3 are totally reflected at an approximately same point 13 on the end face, and the generated terahertz wave 4 is emitted roughly vertically to the end face.

Abstract: A two-pump optical parametric device (OPD) having a nonlinear birefringent fiber, in which various four-wave mixing (FWM) processes can occur. The OPD applies, to the nonlinear birefringent fiber, two pump waves, each polarized at about 45 degrees with respect to a birefringence axis of the fiber, and a polarized input signal. A relevant FWM process couples the pump waves and the signal to cause the fiber to generate a desired output signal. In one configuration, the relevant FWM process is inverse modulational interaction, which causes the desired output signal to be generated through amplification or attenuation of the input signal. In another configuration, the relevant FWM process is phase conjugation, which causes the desired output signal to be generated through amplification of the input signal. In yet another configuration, the relevant FWM process is Bragg scattering, which causes the desired output signal to be generated as a corresponding idler signal.

Abstract: An optical parametric device, for example an optical parametric generator or amplifier or oscillator, comprising a non-linear material (13) that is operable to generate a signal and an idler wave in response to being stimulated with a pump wave. The non-linear medium is such that the pump and idler waves are substantially collinear and the signal wave is non-collinear.

Abstract: A parametric process is provided for producing visible light at a second wavelength including pumping an optical fiber (4) with input light (1) at a first wavelength of less than one micron, which is longer than the second wavelength, and wherein the optical fiber (4) has zero group velocity dispersion at a third wavelength in the visible or near infrared region and longer than the first wavelength. An optical amplifier that uses the parametric process for producing light at second wavelength is also provided. The optical fiber (4) may be a photonic crystal fiber. The parametric process is tuneable by adjusting the frequency of the zero group velocity dispersion, the frequency of the first wavelength or the birefringence of the optical fiber (4).

Abstract: A system and method for the controlled generation, manipulation, and conversion of individual photons in and for a quantum computing environment or a quantum communication environment are provided. Systems and methods for doubling a single photon in a first propagation mode into two new photons in one or two new propagation modes, combining two photons in one or two propagation modes into a single photon of a single propagation mode, and implementing a pi phase shift on a two-photon state but not on the one-photon state in a fully controlled, consistent, and repeatable fashion are also provided, as well as a source of individual photons having clearly defined and fully controllable properties. Embodiments of the above allow for generation and conversion operations that are up to 100% efficient. The generation, conversion, combination, and phase shifting operations are preferably carried out inside a non-linear ?3 material of a predetermined length.

Abstract: A synchronously-pumped optical parametric oscillator (OPO 10) driven by the second harmonic output of a Kerr-lens-mode-locked Ti:sapphire laser (12) generates femtosecond pulses with wide tunability in the visible and ultraviolet spectrum. The OPO uses bismuth triborate, BiB3O6 (or BIBO) or a substituted form thereof, in collinear critical phase-matching as the nonlinear gain crystal (24). Using simple crystal rotation at room temperature, a continuous tuning range from 480 nm to 710 nm is achieved with a single BIBO crystal (24) and a single set of mirrors (26, 28, 30) for the OPO cavity. The OPO (10) generates up to 27 OmW of average power across the available tuning range and can deliver femtosecond pulses at a repetition rate of 76 MHz.

Abstract: A light source apparatus with modulation function has a wavelength conversion module (75) composed of a nonlinear optical material with a structure having a nonlinear constant modulated periodically. It outputs a difference frequency or sum frequency produced by multiplexing pumping light from semiconductor laser light sources (71) and (72) with different wavelengths through a WDM coupler (74) and by launching the multiplexed light into the optical waveguide. The semiconductor laser light source (72) includes a diffraction grating. The semiconductor laser light source (71) includes a section for modulating output light emitted from its semiconductor laser, and is connected to an external FBG (73) which has a reflection band narrower than a resonance wavelength spacing determined by the device length of the semiconductor laser. The FBG (73) is supplied with the modulated output.

Abstract: A wavelength converter which performs simultaneously wavelength conversion for a plurality of input light wavelengths that are unequally intervals, is provided. The nonlinear material of the wavelength converter has a modulation structure which has modulation of a nonlinear optical constant at a period ?0 in a propagating direction of light, a phase being continuously changed each period ?0 and a continuous phase modulation for a different period ?ph being added to the modulation structure. The nonlinear material has a modulation structure obtained by changing a modulation curve for the phase modulation, wherein a phase mismatch ?? is represented by ??=2?(n3/?3?n2/?2?n1/?1), and at least three peaks at unequally intervals within a plurality of peaks for conversion efficiency represented by 2?/?0+2?i/?f (i=m, m+1, . . . , n: where m and n are positive or negative integers) have highest conversion efficiency.

Abstract: Two-pump optical parametric devices (OPDs), and methods of operating the same, generate desired output signals and idlers having reduced stimulated Raman scattering (SRS) noise levels. When the two-pump OPD is used as a two-pump optical parametric amplifier (OPA), the pumps are polarized perpendicular to each other, and the lower-frequency sideband (signal or idler) is polarized parallel to the lower-frequency pump (perpendicular to the higher-frequency pump). The desired output may be an amplified signal or a generated idler. When the two-pump OPD is used as a two-pump optical frequency converter (OFC), the pumps can be polarized parallel to one another, in which case the signal and idler are both perpendicular to the pumps, or perpendicular to one another, in which case the lower-frequency sideband (signal or idler) is polarized parallel to the lower-frequency pump (perpendicular to the higher-frequency pump).

Abstract: Whispering-gallery-mode (WGM) optical resonators made of crystal materials to achieve high quality factors at or above 1010.

Abstract: A coating between a nonlinear crystal and a silicon prism coupler, prevents transmission of radiation scattered within the crystal by filtering out frequencies outside the silicon bandgap to avoid free carrier absorption, but transmits THz frequencies that correspond to the bandgap.

Abstract: A method of ultrasonic testing comprising conditioning a radiation wave from a laser source by efficiently converting the radiation wave's wavelength to a mid-IR wavelength for enhanced ultrasonic testing of a composite. The method includes passing the radiation wave through a first optical frequency converter where the radiation wave is converted into a signal wave and an idler wave, where the idler wave is at a mid-IR wavelength. The method further includes directing the signal and idler waves to a second optical frequency converter where the signal wave wavelength is converted to a mid-IR wavelength which combines with the idler wave to form a generation wave. The generation wave is directed at a composite surface to be tested.

Abstract: The present invention provides an apparatus and method for producing entangled photon pairs via four-wave mixing in optical fiber. The source of entangled photons is designed to be stable with no manual alignment. This is accomplished with proper system design using polarization maintaining fibers or polarization controllers with feedback control. The source may contain a method of switching the output from an unpolarized entangled state to a polarized state, where the polarized state can be used to more easily align subsequent photon measurement systems to the proper configuration for measuring the unpolarized entangled state. The invention further provides a means to engineer the apparatus, including the use of a periodic filter common to both entangled pairs, such that the wavelength spacing between the pairs can be optimized such that multiple pairs can be generated with reduced adverse influence from Raman scattering.

Abstract: A wavelength conversion device that obtains, from an input light, a wavelength-converted light with a wavelength shift by a wavelength shift amount of ?? is disclosed. The device comprises first and second wavelength converters. The first wavelength convertor shifts a central wavelength of a first wavelength-converted light by a first wavelength shift amount of ??1 relative to a central wavelength of an input light. The second wavelength convertor shifts a central wavelength of a second wavelength-converted light by a second wavelength shift amount of ??2 relative to a central wavelength of the first wavelength-converted light. The first wavelength shift amount of ??1 and the second wavelength shift amount of ??2 satisfy ??1+??2=??.

Abstract: A method and an apparatus for generating a terahertz wave, wherein one end face 12a of a non-linear optical crystal 12 is positioned approximately orthogonally to a direction of generation of a terahertz wave 4, pump light 2 and idler light 3 are totally reflected at an approximately same point 13 on the end face, and the generated terahertz wave 4 is emitted roughly vertically to the end face.

Abstract: A wide-band ultrashort-pulse optical oscillator includes: an optical amplification medium 1 that optically amplifies an incident light having a wide band or a plurality of bands so as to be converted into an oscillation light emitted from an optical resonator; an energy injection element 2 that either injects energy into the optical amplification medium so that light energy is generated, or injects light energy into the optical amplification medium; a negative dispersion element 4 that imparts a negative dispersion to a pulse light of the oscillation light; a mode locker 9 that produces a mode-locking with respect to the pulse light; a positive dispersion element 11 that imparts a positive dispersion to the pulse light; and an optical system formed so that the pulse light passes through a loop-like optical path from the optical amplification medium via the negative dispersion element, the mode locker, and the positive dispersion element, back to the optical amplification medium in at least one of the stated d

Abstract: [Task] To provide the THz wave generator restricting increase in manufacturing cost or large size of the entirety of the apparatus and generating efficiently the several-W THz wave. [Means for Resolution] In a THz wave generator for generating a THz wave from a THz wave generating element by inputting a plurality of laser beams having different wavelengths to the THz wave generating element, at least one laser beam among the plurality of laser beams is formed into a pulse beam by the pulse generator and the pulse beam is amplified by an optical amplifier E and then the pulse beam is inputted to the THz wave generating element F. Preferably, the plurality of laser beams having different wavelengths are generated by inputting single wavelength beam to a multi wavelength generator from single mode laser light source and by inputting light waves having a plurality of wavelengths generated from the multi wavelength generator to wavelength selecting means.

Abstract: The present invention provides methods, systems, and apparatus of improved fiber-based optical parametric oscillators (FOPOs). These oscillators can be used in the creation of short pulsed laser radiation, which are useful in numerous applications, such as characterization of materials and molecules. A relationship between fiber length and performance is realized, where shorter lengths counterintuitively provide greater power and width of output bands. This relationship is used to develop improved FOPOs. For example, fibers of 10 cm or less may be used to obtain superior performance in terms of wavelength tunability (e.g. bandwidth of 200 nm and greater) and output power (e.g. pulse power of 1 nJ). Other realized relationships between length and wavelength position of output bands are also used to select the wavelength range output from the FOPO. The diameter of the fiber may be selected to provide positioning (e.g. a centering) of the range of attainable output wavelengths.

Abstract: A technique for generating variable pulse delays uses one or more nonlinear-optical processes such as cross-phase modulation, cross-gain modulation, self-phase modulation, four-wave mixing or parametric mixing, combined with group-velocity dispersion. The delay is controllable by changing the wavelength and/or power of a control laser. The delay is generated by introducing a controllable wavelength shift to a pulse of light, propagating the pulse through a material or an optical component that generates a wavelength dependent time delay, and wavelength shifting again to return the pulse to its original wavelength.

Abstract: An optical antenna collects, modifies and emits energy at light wavelengths. Linear conductors sized to correspond to the light wavelengths are used. Nonlinear junctions of small dimension are used to rectify an alternating waveform induced upon the conductors by the lightwave electromagnetic energy. The optical antenna and junctions are effective to produce harmonic energy at light wavelengths. The linear conductors may be comprised of carbon nanotubes that are attached to a substrate material, which may then be connected to an electrical port.

Abstract: A laser system for a spectroscopic catheter system uses multiple semiconductor gain media having gain peaks at different wavelengths. The output from the gain media is preferably coupled into single-mode fiber using conventional opto-electronic packaging techniques. As a result, the laser oscillator source has a spectral output that is wider than the gain bandwidth of a single medium to enable it to access the entire spectrum of interest, which is presently in the near infrared. Moreover, the semiconductor gain media can be packaged in a stable and controlled environment for long-term performance.

Abstract: An integrated broad spectral band waveguide optical parametric oscillator (OPO) is disclosed. In accordance with a preferred embodiment of the present invention, a single pump laser is used to drive multiple oscillator (OPO) channels. The waveguide OPO is preferably made of orientation patterned gallium arsenide. The pump laser can be, for example, a fiber laser, a diode laser or a solid-state laser.

Abstract: An optical parametric device, for example an optical parametric generator or amplifier or oscillator, comprising a non-linear material (13) that is operable to generate a signal and an idler wave in response to being stimulated with a pump wave. The non-linear medium is such that the pump and idler waves are substantially collinear and the signal wave is non-collinear.

Abstract: An RGB light source that uses an optical fiber laser to generate a near-infrared (NIR) output light beam, and a wavelength conversion system that receives the output NIR light beam and forms therefrom red, green and blue light beams. The fiber laser includes multiple stages, wherein the first stage includes a solid-state laser to generate an initial NIR light beam. One or more subsequent stages operate to amplify the NIR light beam to form a relatively high-average-power output NIR light beam. Only light from the fiber laser is used to generate the red, green and blue-wavelength output light beams. The wavelength conversion system includes three or fewer non-linear optical (NLO) units. A color display that utilizes the RGB light source is also disclosed.

Abstract: An optical parametric oscillator includes a source of coherent energetic pump optical signals and an optical resonator cavity which includes a set of optical parametric amplifying (OPA) crystals and a set of optical elements such as mirrors disposed along an optical path. The optical elements are configured (1) to direct an oscillation optical signal generated by the OPA crystals along the optical path, (2) to provide input coupling of the energetic pump optical signals such that each energetic pump optical signal travels through only one of the OPA crystals to result in a corresponding depleted pump optical signal, and (3) to provide output coupling of the depleted pump optical signals to prevent each depleted pump optical signal from traveling through more than one of the OPA crystals. Resonator cavities have multiple-leg configurations, including “L” and “U” shapes, and either linear (or standing-wave) or ring architectures.

Abstract: A parametric device having a non-linear material (4) for generating an idler wave and a signal wave (16) in response to a pump wave (14), the pump, idler and signal waves being non-collinear, the device having a cavity (10, 11) resonant at the pump wavelength and means for varying the angle between the propagation directions of the pump and idler waves.

Abstract: There is provided an optical parametric oscillator capable of converting a wavelength in a broader range and generating an output beam with high efficiency. The optical parametric oscillator includes: a non-linear optical material optical parametrically converting a beam pumped from a laser; and input and output optical devices opposing each other, the input and output optical devices guiding the optical parametrically-converted beam to the non-linear optical material to oscillate, wherein the input optical device includes an input optical mirror guiding the pumping beam into the oscillator, and the output optical device includes a plurality of output optical mirrors each guiding the optical parametrically-converted beam outside the oscillator, the output optical mirrors having reflectivities different from one another with respect to a wavelength of the optical parametrically-converted beam.

Abstract: Optical apparatus including an optical frequency conversion device, pumped by a non-polarized light beam. The apparatus may include a pump incident side, such as an optical fiber emitting non-polarized light beam, a polarization beam splitter to split the incident beam into two polarized beams, beam forming optics to shape the beams and rotate their polarization as required and couple them into the conversion device, and an optical frequency conversion device to convert the wavelength of both beams into a new wavelength.

Abstract: A four-wave mixing squeezed light source includes: a mixing medium having chi(3) non-linear characteristics including two atomic ground states coupled to each other by transitions through optically-excited states; a pump beam having a polarization and a frequency, said frequency being near the ground-to-excited atomic transition but far enough from the atomic transition such that the pump beam is substantially unabsorbed; and a probe beam having a polarization that is orthogonal with respect to the pump beam polarization, the probe beam having a frequency of the pump beam frequency plus or minus a frequency splitting of the two atomic ground states. The mixing medium, the pump beam and the probe beam interact to produce a phase conjugate beam having a polarization that is orthogonal to the pump beam polarization, such that the beams are non-degenerate with the pump beam, and the probe beam is amplified.

Abstract: An optical signal and pump light are input to a nonlinear optical medium. In the nonlinear optical medium, the optical signal is amplified with a nonlinear effect caused by the pump light. A monitor circuit monitors parametric gain in the nonlinear optical medium. A first power controller increases input power of the optical signal so that the gain reaches saturation. A second power controller controls input power of the pump light so as to obtain a desired gain.

Abstract: An optical buffer employing Bragg scattering (BS), in which two pump signals are combined with an input (data) signal in a four-wave mixing (FWM) medium to frequency convert the input signal into an idler signal, which is applied to a dispersive medium, in which the idler signal propagates at a speed different from that of the input signal. By selectively turning on and off a pump, e.g., at bit-level switching rates, the BS-based frequency conversion can be selectively performed on particular bits in the input signal, e.g., to generate an output signal having reordered bits. A BS-based optical buffer can (1) be tuned to achieve different amounts of delay; (2) support single-channel or multiple-channel, classical or quantal communications; (3) be implemented with co-phased pump-phase modulation to suppress stimulated Brillouin scattering, while inhibiting spectral broadening of the idler signal; and (4) provide polarization independence using standard polarization-diversity techniques.

Abstract: A multi-frequency light producing method and apparatus multiplies the number of optical channels present in an incident wavelength division multiplexed (WDM) signal light source by four-wave mixing (FWM) the WDM signal with at least one pump lightwave at least one time. By FWM the WDM light and a pump lightwave multiple times, wherein each FWM process is executed with a pump lightwave having a different frequency, either in series or parallel, the number of optical channels produced as a result of FWM effectively increases the number of optical channels present in addition to those from the WDM signal. The light producing method and apparatus can be employed in a telecommunications system as a an inexpensive light source producing a plurality of optical frequencies.

Abstract: Methods and apparatus for local oscillator generation are provided. In a method embodiment, a method of signal processing includes splitting a signal having a first frequency into at least a first portion and a second portion. The method also includes generating a second signal having a second frequency at a predetermined frequency difference from the first frequency by optically modulating the first portion. In addition, the method includes generating a third signal having a frequency component at a frequency that is approximately the same as the predetermined frequency difference from the first frequency by combining the second portion with the second signal.

Abstract: A simple and low-cost apparatus amplifies short optical pulses (e.g., in the femtosecond domain) to high pulse energies using energy stored in an enhancement cavity. The enhancement cavity is first filled with pump light from a pump laser; and a signal laser then directs a signal pulse into the cavity, where the signal pulse and pump laser both pass through a non-linear medium for parametric amplification of the signal pulse, wherein energy from the aggregated pump light is transferred to the signal pulse, which then exits the enhancement cavity.

Abstract: A wavelength conversion element having multi-gratings free from damage propagation and a light generating apparatus using it, and a wavelength conversion element having multi-gratings to make a thermal distribution centrosymmetric, and being free from damage propagation, are provided. The wavelength conversion element is realized by comprising a holder and plural prismatic ferroelectric single crystals disposed in the holder, wherein plural prismatic ferroelectric single crystals have at least five planes; the aspect ratios of planes perpendicular to respective longitudinal directions of the plural prismatic ferroelectric single crystals are virtually unity; and each of the plural prismatic ferroelectric single crystals has a domain inversion structure with a predetermined period in the direction perpendicular to the polarization direction thereof, and is arranged in a way that said direction perpendicular to the polarization direction is the same as those of the other crystals.

Abstract: In nonlinear optical crystal 183D, each step of wavelength conversion can be performed using another fundamental wave that is output from light output unit 1612, without using the fundamental wave whose output level has been attenuated after going through wavelength conversion for several steps (wavelength conversion in nonlinear optical crystals 183A to 183C). Therefore, the wavelength conversion efficiency improves and the peak power of optical amplifiers 1611 and 1612 can be suppressed, which allows the wavelength of lights that are output from optical amplifiers 1611 and 1612 to be further narrowed.

Abstract: An optical buffer employing Bragg scattering (BS), in which two pump signals are combined with an input (data) signal in a four-wave mixing (FWM) medium to frequency convert the input signal into an idler signal, which is applied to a dispersive medium, in which the idler signal propagates at a speed different from that of the input signal. By selectively turning on and off a pump, e.g., at bit-level switching rates, the BS-based frequency conversion can be selectively performed on particular bits in the input signal, e.g., to generate an output signal having reordered bits. A BS-based optical buffer can (1) be tuned to achieve different amounts of delay; (2) support single-channel or multiple-channel, classical or quantal communications; (3) be implemented with co-phased pump-phase modulation to suppress stimulated Brillouin scattering, while inhibiting spectral broadening of the idler signal; and (4) provide polarization independence using standard polarization-diversity techniques.

Abstract: An optical parametric amplifier of the invention comprises a nonlinear amplification section to which a signal light and a pump light are injected via a coupler. The nonlinear amplification section is constructed by connecting in multiple stages a plurality of polarization retaining highly nonlinear optical fibers (HNLFs) having mutually different zero-dispersion wavelengths and dispersion slopes. The zero-dispersion wavelengths of the HNLFs are on the short wavelength side of a pump light wavelength, and are shorter towards the output side HNLF. Furthermore, the arrangement is set such that the dispersion slopes of the HNLFs become steeper towards the output side HNLF. As a result, it is possible to realize an optical parametric amplifier that is high gain and broadband.

Abstract: A frequency-conversion arrangement including one or more optically nonlinear crystals is located in an enclosure. Radiation residual from the frequency conversion is directed into an optical fiber having one end in the enclosure for receiving the residual radiation and an opposite end outside of the enclosure for disposing of the residual radiation outside of the enclosure.

Abstract: Two-pump optical parametric devices (OPDs), and methods of operating the same, generate desired output signals and idlers having reduced stimulated Raman scattering (SRS) noise levels. When the two-pump OPD is used as a two-pump optical parametric amplifier (OPA), the pumps are polarized perpendicular to each other, and the lower-frequency sideband (signal or idler) is polarized parallel to the lower-frequency pump (perpendicular to the higher-frequency pump). The desired output may be an amplified signal or a generated idler. When the two-pump OPD is used as a two-pump optical frequency converter (OFC), the pumps can be polarized parallel to one another, in which case the signal and idler are both perpendicular to the pumps, or perpendicular to one another, in which case the lower-frequency sideband (signal or idler) is polarized parallel to the lower-frequency pump (perpendicular to the higher-frequency pump).

Abstract: The present invention relates to a beam-guiding and/or frequency-converting optical system as well as to a method of manufacturing same, wherein a beam-emitting optoelectronic component (1), which comprises at least one beam-emerging surface (2) for the emergence of a beam, is provided and connected to a surface (5) of a base (4) in such a manner that the emerging beam extends approximately in parallel with the surface (5) of said base (4). Once the optoelectronic component (1) has been connected to said base (4), a wave-guiding stratified system (4) is deposited and structured and/or locally modified on the surface (5) of said base (4) for guidance and/or frequency conversion of the beam in such a way that a gap-free contact is created between said beam exit surface (2) and said stratified (6) and a pre-determinable beam guidance is achieved.

Abstract: A system for sensing characteristics of the environment is disclosed. Sensors utilize exponential growth of a signal initiated by interaction of a sensor element with characteristics of the environment. Specific substances in the environment can be detected. The sensor element may be intrinsically sensitive to the specific substance or can be coated with a material that is sensitive to the specific substance. The sensor component is designed such that it can be made to cause exponential growth of a system signal. The exponential growth of the sensor signal is produced by parametric amplification.

Abstract: The oscillator comprises two resonant cavities in which a non-linear crystal (3) is situated. The incident pumping radiation Rpe follows an emitting path across the crystal, the generated signal and complementary radiation carry out numerous emitted and return paths in the cavities, hence across the crystal and are thus converted into an inverse pumping radiation on the return paths thereof. According to the invention, a device (4) is incorporated in the oscillator for reflection of a fraction of the pumping radiation equivalent to the inverse pumping radiation in the absence of the device.