50 results about "Nonlinear photonic crystal" patented technology

The invention belongs to the field of optical test equipment and a use method thereof and particularly discloses an optical fiber dispersion measurement system which comprises a light source system and an interference measurement system, wherein the light source system comprises a pulse laser, an optical isolator, a narrow band filter slice, a reflector set and a photonic crystal optical fiber for a light source; the pulse laser, the optical isolator, the narrow band filter slice, the reflector set and the photonic crystal optical fiber for the light source are sequentially arranged along an optical path; the interference measurement system comprises a beam splitter, a measurement arm for receiving beams reflected and transmitted by the beam splitter, and a reference arm, and optical fiber assemblies to be measured are arranged in the measurement arm; both ends of the photonic crystal optical fiber for the light source are connected with a three-dimensional optical fiber coupling platform; and the beam splitter is additionally provided with an output end, the optical path arranged behind the output end is sequentially provided with a polarizer, a narrow band filter, an endless single mode photonic crystal optical fiber assembly and a data collection and treatment system. By selecting a highly nonlinear photonic crystal optical fiber with a special ventage structure as the photonic crystal optical fiber for the light source, the system can generate super-continuum spectrum white lights so as to measure a dispersion coefficient with high accuracy, high efficiency and low cost.

A photonic crystal all-optical switch is an all-optical switch (photonic crystal structure), in particular a migrating nonlinear photonic crystal all-optical switch of a defect mode. The photonic crystal all-optical switch comprises triangular lattice photonic crystals (1), a waveguide area (2), a traction area (3) and a nonlinear resonant cavity (4), wherein the triangular lattice photonic crystals (1) are large air hole type photonic crystals in triangular periodic distribution along X and Z axes, symmetric linear defects are introduced at two ends of the triangular lattice photonic crystals to form the waveguide area (2), a central air hole of the triangular lattice photonic crystals (1) is provided with the nonlinear resonant cavity (4), the traction area (3) is arranged between the waveguide area (2) and the nonlinear resonant cavity (4), and signal light is input from the left end of the waveguide area (2) and output from the right end of the waveguide area (2); and control light vertical to the X and Z axes is incident to the central nonlinear resonant cavity (4) along a medium column.

The invention relates to an ultrashort laser pulse time domain compression device and method. The device comprises a femtosecond laser oscillator, a Faraday isolator, a first objective lens, a high nonlinear photonic crystal fiber, a second objective lens and a 4f pulse shaping unit. Femtosecond pulses emitted by the femtosecond laser oscillator pass through the Faraday isolator and then are coupled into the high nonlinear photonic crystal fiber through the first objective lens to generate continuous spectral pulses. The continuous spectral pulses are collimated by the second objective lens and then enter the 4f pulse shaping unit. The 4f pulse shaping unit is configured to measure and compensate the frequency-domain phase distortion of the continuous spectral pulses, and compress the continuous spectral pulses. The frequency-domain phase distortion is determined by phase interference scanning in the multi-photon pulses. The ultrashort laser pulse time domain compression device and method greatly improve the precision of the pulse time-domain compression by using the frequency-domain 4f pulse shaping unit.

The invention discloses a small-core cluster photonic crystal fiber with a large effective mode field area and high non-linearity, which pertains to the technical field of fibers. The effective mode field area of the photonic crystal fiber is composed of the bunching of a plurality of fibers with a core diameter of 1 to 2 microns; small air vent holes are arranged around each small fiber core to form a covering; the periphery of a small bunching core is the structure of a multi-layer air vent hole covering. The photonic crystal fiber has the advantages that the photonic crystal fiber retains and promotes the original feature of high non-linearity, has relatively large effective mode field area and can bear relatively large pump energy; when the photonic crystal fiber is combined with a photonic crystal fiber mode lock laser with high power, a small-sized super-continuum laser source with high power is formed.

The invention discloses a photon crystal optical fiber, whose transect includes a fiber core and a cladding. The cladding is identical to the common photon crystal optical fiber, and is a peripheral area surrounding the fiber core and homogeneously distributed with identical structural airports. The airports are periodically arranged in the optical fiber base material, the dimension of the airports is the wavelength magnitude, every three adjacent airport units constitute a regular triangle. The fiber core is jointly constituted by an optical fiber base material locating at the center part of the optical fiber end-face and another solid material, wherein, the refractivity of the solid material is higher than that of the optical fiber base material, two blocks of solid material are symmetric distributed at the both sides of the optical fiber end-face center and the minimum distance of their outer margins should be smaller than 400nm in order to produce a narrow slit. The transect of the solid high-index material may be circular, elliptical shape, square or oblong; the diameter of the circular cross section, the minor axis diameter of the elliptical cross-section, the edge length of the square cross section, and the short edge length of the oblong cross section should be smaller than 400nm. By changing the fiber core structure of the photon crystal optical fiber, the invention uses the narrow slit to limit the light to spread in the nano-scale dimension low refractivity base material, thereby largely decreasing the effective model field area, and causing the photon crystal optical fiber to have ultra-high non-linearity and ultra-low limitation waste. The invention uses a simple and convenient manufacturing structure to resolve the problem in the prior photon crystal optical fiber technique, which is be difficult to implement ultra-high non-linear.

The invention is suitable for the field of optical fiber and provides a device for generating super continuous spectrums. The device comprises a continuous wave fiber laser, a high nonlinear photonic crystal fiber and a high nonlinear normal dispersive optical fiber, wherein the continuous wave fiber laser is used for providing pump light; the high nonlinear photonic crystal fiber is welded with an output tail fiber of the continuous wave fiber laser and is used for performing nonlinear conversion on the pump light provided by the continuous wave fiber laser so as to form the continuous spectrums; the high nonlinear normal dispersive optical fiber is welded with the high nonlinear photon crystal fiber and is used for flattening and expanding the formed super continuous spectrums. The device for generating the super continuous spectrums can flatten the super continuous spectrums with high spectral intensity peaks. Simultaneously, the spectrums further expand towards a long wave direction so as to obtain high flat broadband super continuum output.

The invention provides a multi-wavelength micro illumination device. In the device, a laser pulse output by a picosecond pulse laser or a femtosecond pulse laser is incident to a nonlinear photonic crystal fiber to obtain a broadband laser source; the pulsed laser beam output by the broadband laser source is incident to an acoustooptical modulator to obtain a laser pulse beam with a repetition frequency; a beam splitter and a plurality of reflectors are arranged on the optical path of the laser pulse beam; the laser pulse beam is divided into n parallel output beams (n is a natural number equal to or larger than 2); a dispersion prism or a diffraction grating, a lens (a), a spatial light modulator and a lens (b) are sequentially arranged on the optical path of each output beam; and (n-1) output beams respectively pass through a right angle prism after passing through the dispersion prism or the diffraction grating, the lens (a), the spatial light modulator and the lens (b) to obtain n parallel output beams with different delay time. The multi-wavelength micro illumination device provided by the invention can provide laser wavelengths with a wide waveband range from near ultraviolet to mid-infrared and high spectral energy density above 1 nJ / nm, and is suitable for excitation of the most of fluorescence and Raman samples. Additionally, the plurality of laser wavelengths are from the same laser source so as to obviate the problem of synchronous time maladjustment, and the apparatus cost can be reduced greatly by using one pulse laser.

The embodiment of the invention provides an infrared single photon detection apparatus comprising a nonlinear photonic crystal waveguide, a filter, and a visible light single photon counting module, wherein the nonlinear photonic crystal waveguide and the filter are integrated into a single chip; the nonlinear photonic crystal waveguide is used to up-convert an infrared single photon signal into a visible light single photon signal. The filter is used for filtering the noise in the visible light single photon signal. The visible single photon counting module is used for detecting the visible light single photons of the filtered visible light single photon signal. The low practicability in the prior art can be solved by carrying out infrared single photon detection by means of the infrared single photon detection apparatus having a smaller volume.

The invention provides a nonlinear photonic crystal capable of directly generating two-photon frequency and path super-entanglement. The nonlinear photonic crystal selects a 5% MgO doped LiNbO3 crystal under the conditions of room temperature and class I phase matching (e->-o+o). Meanwhile, the invention provides a two-photon frequency and path super-entanglement generation method based on the nonlinear photonic crystal. According to the method, pump light is normally incident to the surface of the nonlinear photonic crystal in the positive z direction, signal light and idle light are generated after interaction, and the signal light and the idle light meet the frequency and path super-entanglement relation. Simulation is carried out on the nonlinear photonic crystal and the two-photon frequency and path super-entanglement generation method thereof, it is verified that the maximum entanglement state can be generated, other parameter processes are effectively inhibited, and the super-entanglement state with relatively high quality is generated.

The invention discloses a double-frequency CARS measuring device and method based on a bound-state light soliton. The device at least comprises a femtosecond laser (1), an ultra-short pulse beam splitting adjusting part, a Stokes light pulse generating and transmitting light path, a pump light transmitting light path, a beam combiner (15) and a CARS microimaging system (16) which are connected insequence. Based on a soliton self-frequency-shift effect and a birefringence effect when an ultrashort pulse is transmitted in a high-nonlinearity photonic crystal fiber, a bound-state light soliton with overlapped time domains and separated wavelengths are generated. When the bound-state light soliton is used as a Stokes light pulse of a CARS system, the bound-state light soliton can simultaneously act with a pump light pulse to realize simultaneous excitation and detection of resonant frequencies of two molecules to be detected. In the invention, a system structure of the traditional CARS measurement system is simplified, system cost is reduced, and a chemical selective imaging capability and a multi-molecule simultaneous detection capability of the CARS system are improved.

The invention is suitable for the field of optical fiber and provides a device for generating super continuous spectrums. The device comprises a continuous wave fiber laser, a high nonlinear photonic crystal fiber and a high nonlinear normal dispersive optical fiber, wherein the continuous wave fiber laser is used for providing pump light; the high nonlinear photonic crystal fiber is welded with an output tail fiber of the continuous wave fiber laser and is used for performing nonlinear conversion on the pump light provided by the continuous wave fiber laser so as to form the continuous spectrums; the high nonlinear normal dispersive optical fiber is welded with the high nonlinear photon crystal fiber and is used for flattening and expanding the formed super continuous spectrums. The device for generating the super continuous spectrums can flatten the super continuous spectrums with high spectral intensity peaks. Simultaneously, the spectrums further expand towards a long wave direction so as to obtain high flat broadband super continuum output.

A laser system (10) for use in photonic excitation investigation of a target object, in which the target object interacts with incident photons and emits a corresponding photon which is detected and used to generate an image of the target object. The laser system (10) includes a pulsed fiber laser (14) for producing a laser beam, and a non-linear photonic crystal fiber (16) for carrying the laser beam from the laser (14) to an instrument (18) for photonically exciting the target object. The photonic crystal fiber (16) allows for switching, or tuning, the wavelength of the laser beam. In two-photon microscopy, the laser system (10) allows for providing multiple wavelengths for exciting a plurality of different fluorophores simultaneously. In coherent Raman imaging and spectroscopy, the laser system (110) allows for using a single laser to provide two laser beams of different wavelengths.

The present invention relates to a nonlinear fiber, in particular to a photonic crystal fiber with high nonlinearity and flattened dispersion at long wavelength, and pertains to the field of fiber communication and optical signal processing. The structure of the present invention is characterized in that a low duty-cycle hole defect structure is provided in the pure-quartz fiber core zone, and the fiber cladding comprises a high duty-cycle hole periodic structure. The nonlinear photonic crystal fiber in the present invention, compared with the simple total-reflection nonlinear photonic crystal fiber, overcomes the bottleneck that zero dispersion can only be adjusted at short wavelength, and realizes that zero dispersion can be adjustable in a wide range of spectrum and the property of flattened dispersion is provided at long wavelength. The invention can be widely applied to optical devices in the field of communication-wavelength photonic technology, such as the multi-wavelength light source for long wavelength communication, the quantum information source and so on.