87 results about "Parametric oscillator" patented technology

There is provided a non-linear optical device for enhancing the bandwidth accessible in the nonlinear generation of an optical signal. The device comprises a planar optical waveguide, the planar optical waveguide being operative to generate an optical output from an optical input having an input bandwidth by means of a non-linear optical process, the optical output having a wavelength within an accessible bandwidth, wherein the planar optical waveguide is operative to enhance the accessible bandwidth such that the ratio of the accessible bandwidth to the input bandwidth is at least 4. The device is particularly applicable to broad optical continuum generation, but may also be used in a parametric oscillator or amplifier arrangement with broad tuning range.

There is provided a non-linear optical device for enhancing the bandwidth accessible in the nonlinear generation of an optical signal. The device comprises a planar optical waveguide, the planar optical waveguide being operative to generate an optical output from an optical input having an input bandwidth by means of a non-linear optical process, the optical output having a wavelength within an accessible bandwidth, wherein the planar optical waveguide is operative to enhance the accessible bandwidth such that the ratio of the accessible bandwidth to the input bandwidth is at least 4. The device is particularly applicable to broad optical continuum generation, but may also be used in a parametric oscillator or amplifier arrangement with broad tuning range.

There is provided a non-linear optical device for enhancing the bandwidth accessible in the nonlinear generation of an optical signal. The device comprises a planar optical waveguide, the planar optical waveguide being operative to generate an optical output from an optical input having an input bandwidth by means of a non-linear optical process, the optical output having a wavelength within an accessible bandwidth, wherein the planar optical waveguide is operative to enhance the accessible bandwidth such that the ratio of the accessible bandwidth to the input bandwidth is at least 4. The device is particularly applicable to broad optical continuum generation, but may also be used in a parametric oscillator or amplifier arrangement with broad tuning range. The planar waveguide geometry permits easy integration in more complex photonic integrated circuits such as a Michelson interferometer for low coherence interferometry based optical coherence tomography.

The invention relates to the non linear optical frequency conversion. To realize output of high power THz wave which can be continuously tuned, and stable running at room temperature, the technical scheme used by the invention is that: a tunable terahertz radiation source based on difference frequency cherenkov effect is composed of a laser device, a frequency doubling crystal, a double wavelength parametric oscillator, a harmonic mirror, a polarization filter, a combined beam mirror, a column lens and a difference frequency crystal; the harmonic mirror is placed between the frequency doubling crystal and the double wavelength parametric oscillator; the double wavelength parametric oscillator is II type phase matching KTP (Potassium Titanyl Phosphate) crystal OPO (Optical Parametric Oscillator); the polarization filter, the combined beam mirror and the column lens are arranged between the parametric oscillator and the difference frequency crystal; the difference frequency crystal is amagnesium oxide doped lithium niobate crystal with molecular formula of MgO:LiNbO3 or MgO:LN, and the generated THz wave is coupled and output by an Si prism on the side surface of the difference frequency crystal. The tunable terahertz radiation source based on difference frequency cherenkov effect is mainly applied to the optical frequency conversion.

The invention discloses a multi-wavelength terahertz wave parametric oscillator, which comprises a laser pump cavity and a terahertz wave parametric oscillation cavity, wherein the laser pump cavity consists of a totally reflecting mirror, a one-fourth wave plate, an electro-optical Q-switch device, a polarizer, a pulse laser pump source module, a micropore diaphragm and a laser output mirror; the terahertz wave parametric oscillation cavity comprises two right-angle prism resonance cavities respectively consisting of a right-angle prism, a reflector, a MgO:LiNbO3 crystal arranged between themicropore diaphragm and the laser output mirror, and a plurality of semi-circular output mirrors; and two silicon prism arrays are arranged on the surface of the MgO:LiNbO3 crystal. Pump light oscillating back and forth in the laser pump cavity is vertically transmitted to the MgO:LiNbO3 crystal, and two beams of oscillating Stokes light and two groups of four-beam terahertz waves are generated through excitation in the two right-angle prism resonance cavities, and are transmitted out of the silicon prism arrays. The continuous tunable output of the two groups of four-beam terahertz waves canbe realized, and the output energy is basically equal.

The invention relates to a laser and provides a dual-wavelength tunable inner cavity tera-hertz parametric oscillator and a using method thereof to realize the output of continuous tunable dual-wavelength high-power THz wave and the stable operation at room temperature. The invention adopts a technical proposal that: a pumplight resonant cavity consists of a planar holophote, a laser and an output mirror; the laser is a quasi-continuous semiconductor laser array side-pumped neodymium yttrium aluminum garnet Nd:YAG5 laser; a back pressure type electro-optical switch Q consisting of monopotassium phosphate KD P crystal and a polaroid is arranged between the planar holophote,and the laser; a TPO resonant cavity consisting of a magnesium-doped lithium niobate MgO:LiNbO3 crystal and two cavascopes is arranged between the laser and the output mirror; and the optical axis of the TPO resonant cavity and the optical axis of the pumplight resonant cavity are non-colinear; and the side of the magnesium-doped lithium niobate MgO:LiNbO3 crystal and an array silicon prism are coupled to output the tera-hertz wave. The dual-wavelength tunable inner cavity tera-hertz parametric oscillator and the using method are mainly used for manufacturing the laser.

The invention belongs to the technical field of parametric oscillators and relates to an end-pumped mid-infrared KTA parametric oscillator. The end-pumped mid-infrared KTA parametric oscillator comprises a pumping source, a coupling lens set, an Nd:YVO4 laser and an intracavity optical parametric oscillator arranged in the Nd:YVO4 laser, wherein the pumping source adopts a semiconductor laser withoutput wavelength of 808 nm and outputs a laser crystal passing through a laser crystal Nd:YVO4 pumped at the rear end of the coupling lens set; the Nd:YVO4 laser is a flat-concave cavity for generating linearly polarized 1064 nm laser light, and a laser crystal Nd:YVO4, an acousto-optic Q-switch and the intracavity optical parametric oscillator are arranged in the Nd:YVO4 laser in sequence; an anti-reflection film with 808 nm and an anti-reflection film with 1064 nm are coated at both ends of the Nd:YVO4 laser crystal; a 1064 nm high anti-reflective film and a 1.5-1.6 mum highly reflective film are coated on an input mirror for the intracavity optical parametric oscillator, a KTA crystal is arranged in the cavity mirror, and dielectric films for performing anti reflection to base frequency light 1064 nm, signal light 1.5-1.6 mum and idle light 3.5 mum are coated at the both ends of the cavity mirror. The mid-infrared laser output with low threshold value, high efficiency and high-repetition frequency can be obtained in the invention.

The invention discloses a broad-tuning waveguide terahertz radiation source. The broad-tuning waveguide terahertz radiation source comprises a laser pump source, a dual-wavelength parametric oscillator, a cylindrical lens and a panel waveguide, wherein the laser pump source outputs 532nm Q-switched pulses to the dual-wavelength parametric oscillator, the dual-wavelength parametric oscillator generates dual-wavelength pulses which are within the range, wherein the center of the range is a degeneracy point, and the radius of the range is 1064nm, the dual-wavelength pulses are focused through the cylindrical lens, and are coupled to a core layer of the panel waveguide, narrow-linewidth THz waves are generated through the second-order non-linear difference frequency effect, a THz radiation mode is generated through the Cherenkov phase matching mode, and sidewise coupling output is achieved. Due to the fact that the structure is adopted, the tuning range is expanded, broadband tuning within the range from 0.1THz to 7THz can be achieved, high-efficiency coupling of the THz waves is achieved, coherent THz radiation output with broad tuning and the narrow linewidth is finally achieved, and the broad-tuning waveguide terahertz radiation source can be widely applied to the fields such as the biomedicine imaging field, the high-resolution spectral analysis field, the material detection field and the medical diagnosis field.

A parametric oscillator oscillates a plurality of pseudo spin pulses SPi having mutually an identical oscillation frequency by using parametric oscillation, an interaction implementing unit performs feedback implementation of a magnitude and a sign of interaction related to each pseudo spin pulse SPi (the proportionality coefficient λi+ΣJijσj+ΣKijkσjσk with respect to σi) by using a tentative measurement result of oscillation phases φi(tentative) of the plurality of pseudo spin pulses SPi, and a pseudo spin measuring unit measures the pseudo spins σi of the plurality of pseudo spin pulses SPi, based on a final measurement result of oscillation phases φi(steady) of the plurality of pseudo spin pulses SPi.

The invention relates to a multipoint vertical surface emitting terahertz parametric oscillator, which comprises a laser pumping system and a Stokes laser oscillator, the Stokes laser oscillator comprises a back cavity mirror, an output mirror and a nonlinear crystal, a laser beam generated by the laser pumping system passes through the nonlinear crystal in a resonant cavity, and because of the Raman and infrared active vibrational mode of the nonlinear crystal, stimulated exciton scattering is caused and a nonlinear parametric process is generated: obtaining a terahertz wave of 0.6THz to 3.0THz. By using a new crystal design, the multipoint vertical surface emitting terahertz parametric oscillator disclosed by the invention can simultaneously obtain N equal to 2, 3, 4, ellipsis, n plus 1 (n is a natural number) beams of terahertz wave outputs under the same pumping condition; for example, when N is equal to 5, compared with the total energy of only one beam of terahertz wave output, the total energy of terahertz output is increased by 3.6 times.

A fiber optical parametric oscillator is formed using photonic crystal fibers, also known as microstructure fibers or holey fibers. The optical parametric oscillator includes only a few meters of microstructure fiber. In one embodiment, the microstructure fiber is disposed between a highly reflective mirror and a diffraction grating in a simple Fabry-Perot configuration wherein the diffraction grating is tuned to reflect a particular wavelength of the signal wave back to the microstructure fiber. In another embodiment, the microstructure fiber is disposed in a ring cavity and the parametric oscillator is synchronously pumped. The parametric oscillator may be implemented with free space optics or use all fiber optic components.

The invention relates to an optical parametric oscillator, which comprises a nonlinear optical material (1) with the double-zero dispersion wavelength, a high reflector (2), an output mirror (3), a parametric oscillation optical beam collimator (4), a parametric optical line width compressor (5), a pumped optical coupler (6), a lambda / 2 phase retarder (7), a laser power controller (8) and an optical isolator (9). The nonlinear optical material (1) has a double-zero dispersion wavelength and is arranged in a resonant cavity formed by the high reflector and the output mirror. The pumped optical wavelength is in the anomalous dispersion regime of the photonic crystal fiber, thereby ensuring the phase matching conditions and generating the highly efficient four-wave mixing effect. For the parametric oscillation formed by simplifying the four-wave mixing, the wavelengths of the two parametric lights are respectively arranged at the double-zero dispersion wavelength of the photonic crystal optical fiber, thereby realizing the group velocity dispersion compensation of the parametric light, solving the problem of the ultra-short pulse dispersion compensation, and greatly reducing the pumping threshold.

The invention provides a dual-waveband multi-wavelength infrared light parametric oscillator. According to the technical scheme, the parametric oscillator comprises a pumping source resonant cavity, a coupling and isolating system and an OPO resonant cavity. A laser beam sent from the pumping source resonant cavity penetrates through the coupling and isolating system and the OPO resonant cavity in sequence and then is sent out. A dual-wavelength pumping source, even a three-wavelength pumping source is used for pumping an OPO system, two pairs, even three pairs of parametric light can meet a phase matching condition at the same time, dual-waveband multi-wavelength laser output can be achieved, and the problem that a single OPO system can not output multiple wavelengths at the same time is solved.

The invention provides a terahertz-wave parametric oscillator based on a cube-corner prism resonant cavity, which is characterized in that the resonant cavity is formed by a right-angle trihedral cube-corner prism and an output mirror; the right-angle trihedral cube-corner prism can rotate around a cavity axis of the resonant cavity; the resonant cavity is internally provided with a MgO: LiNbO3 crystal; a silicon prism array is put on the surface of the MgO: LiNbO3 crystal; and a polarizer is arranged between the right-angle trihedral cube-corner prism and the MgO: LiNbO3 crystal according to a Brewster angle; pumplight is incident to the resonant cavity to simulate the MgO: LiNbO3 crystal to generate terahertz-wave which is sent out by the silicon prism array. Frequency tuning output of terahertz-wave is realized by rotating the output mirror without needing integrally rotating the resonant cavity. The oscillator is a continuously tunable full-solid state terahertz-wave coherent radiation source with small volume, compact structure, and high working stability and can be widely applied to terahertz-wave photoelectronic technique fields such as medical diagnosis, fine spectral analysis, biomedical Imaging, terahertz-wave communication, etc.

Methodology for segmentally modeling Real and Imaginary Parts of Optical Constants or Dielectric Functions using Kroneig-Kramer (K-K) Consistant Oscillators with substantially definite start and end points.

The invention discloses a tunable ultrashort pulse fiber optic parametric oscillator and relates to the fields of parametric oscillators and lasers. The oscillator comprises a tunable laser, an isolator, an intensity modulator, a first amplifier, a filter, a phase modulator, a second amplifier, a first polarization controller, a circulator, a chirped fiber grating, a wavelength division multiplexer, a high-nonlinearity optical fiber, an optical fiber coupler and a second polarization controller. The oscillator adopts a time lens system to compress optical pulse to realize an ultrashort pulse source with tunable repetition frequency and operating wavelength, the repetition frequency is decided by a radio frequency signal applied to a time lens and is very easy to be synchronous to the parametric oscillator. Through utilization of the tunable characteristics of the repetition frequency and the wavelength of the light source of the time lens and combination of time dispersion tuning and pump wavelength tuning mechanism, the fiber optic parametric oscillator can realize the ultrashort pulse laser output at tunable wide working waveband and high pulse quality.

The invention discloses a terahertz wave pseudo heat light source-based imaging device. The terahertz wave pseudo heat light source-based imaging device comprises a terahertz wave parametric oscillator, a terahertz wave focusing lens, a rotating quarry-faced silicon wafer, a terahertz wave collimating lens, a terahertz wave beam splitter, a terahertz transmission light path system, a terahertz reflection light path system and a coincidence measurement circuit, wherein the terahertz transmission light path system consists of an object to be imaged, a terahertz wave collection lens, a terahertz attenuation wafer, a schottky barrier photodiode; and the terahertz reflection light path system consists of a terahertz wave attenuation wafer and a schottky barrier photodiode. The terahertz wave pseudo heat light source-based imaging device has the advantages of being simple in structure, flexible to operate, strong in anti-interference capability, and the like.

The invention discloses a device and method for improving the measurement stability of a Terahertz parametric oscillation source. The device comprises a laser, a Terahertz parametric oscillator, a Terahertz detector, a Stokes light detector, a light-beam collector, a sample, a data acquisition card, a computer and a refractive-index gradient mirror, wherein the Terahertz parametric oscillator comprises a nonlinear crystal and a Stokes light resonance cavity; the laser generates pump light which is incident to the Terahertz parametric oscillator through the refractive-index gradient mirror, onepart of the pump light is collected by the light-beam collector, and the other part of the pump light generates Stokes light and Terahertz wave on the basis of the action of stimulated polariton scattering. The device and method disclosed by the invention have the beneficial effects that by utilization of the characteristic that the stability of the Stokes light is in direct proportion to the stability of the Terahertz in the Terahertz parametric process, and the Stokes light is used as reference light of the Terahertz wave, so that the measurement error caused by instability of the Terahertzparametric source can be eliminated.

The invention discloses a multi-wavelength all-optical 3R regenerative apparatus based on a magnetic control optical fiber parametric oscillator. The multi-wavelength all-optical 3R regenerative apparatus comprises a first optical wave demultiplexing-multiplexing device and an optical annular cavity. The optical annular cavity comprises a coupler, magneto-optic high-nonlinearity optical fibers, an optical demultiplexer, a second optical wave demultiplexing-multiplexing device, an optical amplifier and an optical splitter, wherein the coupler, the magneto-optic high-nonlinearity optical fibers, the optical demultiplexer, the second optical wave demultiplexing-multiplexing device, the optical amplifier and the optical splitter are sequentially connected. Gains of the optical annular cavity are smaller than losses of the optical annular cavity. Compared with the prior art, the multi-wavelength all-optical 3R regenerative apparatus has the advantages that the problem that the system integration level is low due to the fact that a clock extracting unit and a nonlinear optical decision gate unit of a traditional all-optical 3R regenerative apparatus are independent is solved; meanwhile, the multi-wavelength all-optical 3R regenerative apparatus does not need to be synchronized with a reference clock, the problem that clocks can not be accurately synchronized is accordingly solved, the optical signal regenerative cost is accordingly reduced, and the multi-wavelength regenerative apparatus in a wave demultiplexing-multiplexing system is simplified.

A diode-pumped solid state pulsed laser includes an intracavity nonlinear crystal for wavelength conversion by difference frequency mixing and a secondary resonant cavity containing an additional nonlinear crystal for parametric amplification. Primary and secondary cavities are capable of injection seeding and wavelength stabilization resulting in a very narrow, stable, and well defined spectral output. The combination of pump diode pulsing, the implementation of the intracavity parametric oscillator and parametric amplifier results in very efficient operation. Optical fiber coupled parametric oscillator byproduct light allows simple and non-invasive wavelength diagnostics and monitoring upon connection to an optical spectrum analyzer.

The invention discloses a photonic crystal fiber based medium-infrared optical fiber parametric oscillator for degenerating four-wave mixing and relates to a laser oscillator. The photonic crystal fiber based medium-infrared optical fiber parametric oscillator is provided with a laser pumping source, a focusing lens system, four reflectors and a photonic crystal fiber which are sequentially serially connected to an optical fiber annular cavity, the laser pumping source is coupled to enter the photonic crystal fiber through the focusing lens system, oscillation and lasing of signal light in a visible light wave band are guaranteed by the four reflectors, and coherent medium-infrared idle-frequency light is outputted from the tail end of the photonic crystal fiber. Pumping laser with the wave range of 1030-1070nm is coupled to the photonic crystal fiber to stimulate nonlinear effect of the optical fiber four-wave mixing so as to achieve output of the laser in the medium-infrared wave band. The four reflectors in a resonant cavity structure of the oscillator are used to guarantee that the signal light in the visible light wave band is completely reflected in the cavity, and coherent medium-infrared idle-frequency light is completely outputted from the tail end of the photonic crystal fiber so that conversion efficiency is high.

The invention relates to a solid laser device and a related technology. For solving the problems that the structure of a terahertz parametric oscillator is complicated and the system is difficult to miniaturize, the technical scheme adopted by the invention provides a self-frequency-conversion terahertz parametric oscillator. The self-frequency-conversion terahertz parametric oscillator comprises a pumping source (1), a self-frequency-conversion crystal (2), a resonant cavity (3) and a terahertz wave output mirror (4), wherein pumping light emitted by the pumping source (1) is injected into the self-frequency-conversion crystal (2); activated particles in the self-frequency-conversion crystal (2) absorb the pumping light to generate population inversion; laser oscillation is generated under the feedback of the resonant cavity (3); meanwhile, the self-frequency-conversion crystal (2) has a non-linear effect and is used for carrying out frequency conversion on oscillation laser; the laser is converted into terahertz wavebands through parametric oscillation under the action of the same resonant cavity (3); the transmission direction of generated terahertz waves is the same as that of the laser oscillation; the terahertz waves are collected by the terahertz wave output mirror (4) and are reflected and outputted out of the cavity. The self-frequency-conversion terahertz parametric oscillator is mainly applied to the solid laser devices and non-linear optical frequency conversion fields.

The invention provides a high energy Terahertz wave parametric oscillator which comprises a pump source, a first mirror, a second mirror, a third mirror, a P-1-th mirror, a P-2-th mirror,..., a P-(N-1)-th reflector, an S-1-th mirror, an S-2-th mirror,..., an S-(N-1)th mirror, a first MgO:LiNbO3 crystal, a second MgO:LiNbO3 crystal,..., and an N-th MgO:LiNbO3 crystal. The Stokes power generated by N MgO:LiNbO3 crystals is N times the Stokes power generated by only one MgO:LiNbO3 crystal without considering the pump light loss. N MgO:LiNbO3 crystals can produce N Terahertz waves at the same time. The Terahertz wave power generated by N MgO:LiNbO3 crystals is N2 times the Terahertz wave power generated by only one MgO:LiNbO3 crystal. By changing an angle between pump light and Stokes light, frequency tuned Terahertz waves can be acquired. The tuning method is simple and flexibly operated.

The problem of the low efficiency of large quantum defect optical parametric oscillators is solved by recycling unused photons in a process involving pumping additional parametric processes having a common resonant wavelength. In order to improve the efficiency, a series of optical parametric oscillators are pumped with unused signal photons which exist at the output of a previous optical parametric oscillator that generates both signal and idler outputs, with the idler constituting the desired output. In one embodiment, a Holmium pump laser at 40-W produces a 2.1 μm output which is used to pump a first optical parametric oscillator that is non-linear and has a large phase match range crystal, namely ZGP. The output from the first optical parametric oscillator is a 2.8 μm signal and the desired 8.8 μm idler comes out at 4.8-W. The output from the first optical parametric oscillator pumps the second optical parametric oscillator with the unused 2.8 μm signal photons, with the resultant output from the second optical parametric oscillator being a 4.0 μm signal and the 8.8 μm idler at an additional 2.3-W. The 4.0 μm signal pumps the third optical parametric oscillator so as to produce a 7.3 μm signal and the 8.8 μm idler which comes out at an additional 1.1-W. As a result, the combined output power of the idler totals 8.2-W, for an overall efficiency of 20%.

The invention discloses a terahertz wave parametric oscillator based on the cascading parameter effect. After pump light emitted from a pumping source is subjected to bean shrink through a telescope beam shrink system, the pump light enters a MgO:LiNbO3 crystal after passing a reflector and a light beam scanner and is totally reflected in the MgO:LiNbO3 crystal; the pump light generates first-order Stokes light and terahertz waves in the MgO:LiNbO3 crystal through the optical parameter effect, the wave vector of the terahertz waves is perpendicular to the exit face of the MgO:LiNbO3 crystal, and the terahertz waves directly exit from the MgO:LiNbO3 crystal; the cascading parameter process can occur all the time, all orders of Stokes light have respective resonant cavities, the specific area of the side face of the MgO:LiNbO3 crystal is plated with an all-order Stokes light total reflecting film, and the terahertz waves are continuously amplified in the cascading parameter process. The wave vector of the pump light and the wave vector of all orders of Stokes light are both perpendicular to the exit face of the MgO:LiNbO3 crystal, the losses of the pump light and all orders of Stokes light are effectively reduced, the incident angle of the pump light is changed by changing the direction of the light beam scanner, therefore, the included angle between the pump light and the axis of the first-order stokes light resonant cavity is changed, frequency tuning output of the terahertz waves can be achieved, and operation is flexible.

The present invention relates to a barium tetraborate compound and a barium tetraborate non-linear optical crystal, and a preparation method and use thereof, wherein the chemical formulae of the barium tetraborate compound and the non-linear optical crystal thereof are both BaB4O7, with a molecular weight of 292.58; the barium tetraborate non-linear optical crystal has a non-centrosymmetric structure, which belongs to a hexagonal system, and has a space group P65 and lattice parameters of a=6.7233(6) Å, c=18.776(4) Å, V=735.01(17) Å3, and Z=6, wherein the powder frequency-doubled effect thereof is two times that of KDP (KH2PO4), and the ultraviolet cut-off edge is lower than 170 nm. The barium tetraborate compound is synthesized by a solid-phase reaction method; the barium tetraborate non-linear optical crystal is grown by a high-temperature molten solution method; and the crystal has a moderate mechanical hardness, is easy to cut, polish and store, and is widely applicable in the non-linear optics of a double-frequency doubling generator, an upper frequency converter, a lower frequency converter or an optical parameter oscillator etc.

The invention discloses an infrared solid laser based on external cavity optical parametric oscillation and simulated Raman scattering effect. The infrared solid laser comprises a pumping source, a half wave plate, a coupling lens, a laser resonant cavity, an OPO crystal and a Raman crystal; the laser resonant cavity is a four-mirror annular cavity composed of a pair of flat mirrors and a pair ofconcave mirrors; two light paths between two flat mirrors and two concave mirrors are intersected to form a 8-shaped light path; the OPO crystal is located on a light path between two concave mirrors,and the Raman crystal is located on the light path between two flat mirrors; the pumping laser output by the pumping source is incident upon the laser resonant cavity from one concave mirror of the laser resonant cavity after orderly passing through the half wave plate and the coupling lens. The laser system disclosed by the invention is composed of a external cavity optical parametric oscillator(OPO) and the Raman laser; the light parametric oscillator adopts the quasi-phase matching technology to realize the wide tuning of the signal light and the idle frequency light, the signal light isused as base frequency light, thereby realizing the tunable output of the Raman light. The all solid-state design can be realized, the structure is simple and compact, and the working stability is good.

The invention discloses a dual-wavelength narrow-linewidth terahertz wave parametric oscillator. The resonant cavity comprises a right angle prism, a 45-degree total reflective mirror, a dual-blazing-angle grating, a first planar total reflective mirror and a second planar total reflective mirror; an MgO:LiNbO<3> crystals are put in the resonant cavity, and a silicon prism array apparatus is placed on the surface of the resonant cavity; pump light incidents to the resonant cavity, and an included angle of 1.5 degrees is formed between the pump light and the resonant cavity; the dual-blazing-angle grating refers to the dual-blazing-angle grating with crossed periods; the -1 level diffraction efficiency corresponding to one blazing angle is the maximum while the -2 level diffraction efficiency corresponding to the other blazing angle is the maximum; and the two diffraction efficiencies are approximately equal. By separately rotating the 45-degree total reflective mirror, the dual-blazing-angle grating, the first planar total reflective mirror and the second planar total reflective mirror, any dual-wavelength terahertz wave tuning output can be realized, and the dual wavelengths are not affected by each other. The dual-wavelength narrow-linewidth terahertz wave parametric oscillator can be widely applied to the field of the terahertz photo-electronic technique, such as terahertz wave radars, fine spectral analysis, medical imaging, terahertz communication and the like.

The invention relates to an all optical fiber low repetition frequency parametric oscillator used for stimulated Raman scattering. Pump light output by a pump source passes through an isolator and a first optical coupler to enter a parametric oscillation cavity; combined waves of the first and second optical couplers enter a gain optical fiber and a parametric conversion medium; the gain optical fiber amplifies the pump light power of the parametric oscillation cavity entering from the first optical coupler; the output light of the gain optical fiber enters the parametric conversion medium which is in direct fusion with the gain optical fiber; a four-wave mixing effect occurs in the parametric conversion medium; and one part of the output light of the gain optical fiber is directly output,and the other part of the output light of the gain optical fiber returns to the first optical coupler as feedback light, so that the parametric oscillation cavity can be formed. The optical couplersare placed at front of the gain optical fiber so that the gain optical fiber and the parametric conversion medium can be in direct fusion, and therefore, that optical coupler tail fiber generates harmful non-linear effects under low repetition frequency and high peak power pump light can be avoided, parametric conversion efficiency can be enhanced, frequency spectrum noise can be reduced, and theall optical fiber low repetition frequency parametric oscillator can be realized.

The invention relates to an oscillator, in particular to a laser parameter oscillator that is tunable in broad band, which belongs to the laser technical field. The tunable laser parameter oscillator of the invention comprises a laser light source, an input spherical mirror, lath nonlinear optical material, dispersion optical elements (like a dispersion prism, a fiber grating, and the like) and an output mirror. The laser parameter oscillator of the invention has the advantages of wide output linewidth, tunable center wavelength and simple structure.