41 results about "Nonlinear dispersion" patented technology

The invention discloses a rapid K-space linear frequency sweep laser source. The laser source comprises a semiconductor optical amplifier, two polarization controllers, a dispersion control delay line, a circulator, a tuned filter and an output optical fiber coupler, wherein radiation light emitted from the semiconductor optical amplifier is transmitted to the dispersion control delay line through a polarization controller I; the middle port of the circulator is connected to the tuned filer through a first port of the circulator; returned signals are connected to the optical fiber coupler after passing through a third port of the circulator; one path of the optical fiber coupler outputs frequency sweep laser through a 60% port, and the other path of the optical fiber coupler is connected to the polarization controller II and then returns to a ring laser oscillation cavity; the tuned filter mainly comprises two dispersion elements, namely a grating and a prism, and a rotary polygonal mirror; and the linearity of a wave number space is achieved through combination of linear dispersion of the grating and non-linear dispersion of the prism as well as selection on the angles and directions of the prism. The rapid K-space linear frequency sweep laser source can be used for outputting the rapid K-space linear frequency sweep laser, and can obtain the signals of the linearity of the wave number space directly without calibration when being applied to an OCT (Optical Coherence Tomography) imaging system.

A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10−3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

A non-linear dispersive pulse generator for producing pulsed radio frequency electrical signals includes a non-linear dispersive electrical circuit (1) incorporating at least one non-linear element (2) made of a material sensitive to low power signals and a means (5) of producing a variable power control signal (6) and applying it to the element (2) to modify the extent of the non linearity of the element (2) and thereby vary the output frequency of the radio frequency electrical signal generated by the generator.

The invention discloses a power dividing phase shifter. The power dividing phase shifter has a mixed ring structure formed by a power dividing ring and two coupling rings; the input end of the power dividing ring is used as the input of the power dividing phase shifter, the output of the power dividing ring is connected with the two parallel coupling rings, and the output ends of the coupling rings are used as the outputs of the power dividing phase shifter; the power dividing ring is provided with a plurality of corresponding loading stubs (14) for controlling a plurality of output states; each loading stub (14) is provided with a switch (15); and the corresponding loading stubs (14) are controlled by the switches (15) to output power dividing and equal difference phase signals of each state. Based on the nonlinear chromatic dispersion characteristic after the sections are loaded in a transmission line, the output of the power dividing and equal difference phase signals is realized on a micro-strip structure with power dividing function by controlling the loading stubs through the switches. The magnitude of the equal difference phase depends on the electrical length of the loading stubs. The power dividing phase shifter has compact structure, and has power dividing and phase shifting functions at the same time.

A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10−3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

The invention discloses a linear chromatic dispersion combined prism beam splitting device which is formed by combining two prisms made of a special selected material and provided with coating films on the side faces in the mode of 'bottom surface adhesion and opposite coating film faces'. The linear chromatic dispersion combined prism beam splitting device is especially suitable for spectral analysis, spectrum detection and other relevant fields. Based on a control variable method and a differential equation thought, the non-linear chromatic dispersion of the second prism is utilized to compensate non-linear chromatic dispersion of the first prism so as to obtain the linear chromatic dispersion combined prism beam splitting device by controlling light propagation direction and the shapes of the prisms according to the chromatic dispersion characteristic of a first prism material. The linear chromatic dispersion combined prism beam splitting device overcomes the defect of chromatic dispersion non-linearity of the single prism and has the advantages of being wide in free spectral range, high in light energy utilization rate, good in universality, simple in structure, low in price and the like.

An apparatus (104) mitigates cross-channel nonlinear distortion of an optical signal (138) carried on one of a plurality of wavelength channels (118) in a wavelength division multiplexed (WDM) transmission system (100). The apparatus includes a first optical receiver (126) which is arranged to detect a measure (134) of aggregate optical power of the plurality of wavelength channels. A nonlinear dispersion compensator includes means (144) for applying a phase modulation to the optical signal in proportion to the measure of aggregate optical power.

The invention discloses a simulation method for an electromagnetic problem containing a nonlinear dispersive medium, which comprises the following steps of: establishing a geometric model of a medium according to the geometric size of the medium of a device, subdividing the model by adopting a hexahedron unit, acquiring the geometric information of the device and setting the position information of an excitation source; performing region division on the subdivided geometric model according to the kernel number of the parallel parameters; and establishing a differential equation set by adopting a time domain discontinuous Galerkin finite element method, and solving any dispersion model and a nonlinear dispersive medium model in the geometric model of the medium. According to the method, on the basis of the time domain discontinuous Galerkin finite element, by combining the local time stepping and parallel technology, modeling of a complex medium and electromagnetic characteristic analysis of a nonlinear dispersive medium can be achieved; due to the fact that the time domain discontinuous Galerkin finite element method has the advantages of being high in precision and flexible in modeling, an inverse matrix can be directly obtained, and due to the fact that local time stepping and parallel technologies are added, the calculation time can be greatly shortened.

An optical fiber is tapered, for example, by heating it with a CO2 laser. The tapering process is controlled such that the taper transition regions have taper angles selected to minimize loss. The taper waist has a diameter selected to introduce desired dispersion properties and desired nonlinearity. The optical fiber can be used as a dispersion compensator in a fiber laser or other fiber optic system. The nonlinearity in the tapered optical fiber allows the generation of ultrashort light pulses.

The invention discloses a nonlinear dispersion element-based photoelectric oscillator stress sensing system, which comprises an optical frequency comb, a polarization controller, an electrooptical modulator, a circulator, a nonlinear dispersion element, an erbium-doped optical fiber amplifier, a photoelectric detector, a DC blocking device, a low-noise microwave amplifier, a microwave power splitter and a digital processing unit. The nonlinear dispersion element is adopted as a sensing unit and a dispersion value is tuned by stress, so that the generated microwave signal frequency is encoded,and the sensing sensitivity and resolution and the demodulation speed can be effectively improved.

The invention discloses a linear dispersion combined prism optical splitter. The linear dispersion combined prism optical splitter is formed by combining two prisms which are manufactured from special materials and coated with films on the side surfaces by a mode of enabling the bottom surfaces to be clung to each other and the film-coated surfaces to be opposite to each other. The linear dispersion combined prism optical splitter is particularly suitable for the fields of spectrum analysis, spectrum detection and related fields. The linear dispersion combined prism optical splitter is on the basis of the control variable method and differential equation concept; the spreading direction of the line and the shape of the prisms are controlled according to the dispersion property of the first prism material; the nonlinear dispersion of the first prism is compensated according to the nonlinear dispersion of the second prism so as to obtain the linear dispersion combined prism optical splitter. The linear dispersion combined prism optical splitter can overcome the defect of nonlinear dispersion of single prism and has the advantages of being wide in free spectrum range, high in light energy utilization rate, high in generality, simple in structure, and small in cost.

The invention discloses a snapshot type spectrum confocal sensor and a measuring method thereof, and relates to the technical field of sensors, the snapshot type spectrum confocal sensor comprises a collimating lens group, a first spectroscope, a correction plate, a micro lens array, a first focus lens, a volume grating and an area array detector, the collimating lens group is horizontally arranged, the first spectroscope is located under the collimating lens group, the first spectroscope is obliquely arranged by 45 degrees, the correction plate is horizontally arranged and located under the first spectroscope, the first focus lens is vertically arranged and located on the plane where the first spectroscope is located, the first focus lens is arranged on one side of the first spectroscope, and the first focus lens and the correction plate are in reflection mirror symmetry. The micro lens array is horizontally arranged and is positioned right below the correction plate; and according to the invention, an area array dispersion array and a system integrated nonlinear dispersion compensation method are adopted, morphology information acquisition of a snapshot type area is realized, and the method has a height or displacement resolution of micron or even dozens of nanometers.

A method for nonlinearity compensation for an optical transmission link includes determining a dispersion effect of a transmission link; applying a phase conjugation to the transmission link, the phase conjugation responsive to an input wave over the transmission link and providing a conjugated version of the input wave; and configuring an optimum equivalent link responsive to the phase conjugation after the transmission link to compensate for a non-linear dispersion effect from said transmission link.