8 results about "Group velocity dispersion" patented technology

A laser system for the generation of ultrashort optical pulses of light including an oscillator emitting low power and negatively chirped optical pulses with a spectral bandwidth W1, a dispersive connecting segment to maintain the sign of the chirp of the pulses of the oscillator, an optical amplifier for amplifying the optical light pulses and a negative group velocity dispersion segment for compensating phase contributions of the whole propagation process. During the propagation from the output of the oscillator to the end of the optical amplifier, the chirp of the light pulses will change once from negative to positive chirp. After a final compression stage ultrashort optical pulses can be generated.

The utility model relates to the field of optical fiber interference sensors, and discloses an M-Z interference sensor with a small excitation group velocity dispersion difference mode structure. Comprising a light injection single-mode optical fiber, a small-core-diameter step multimode optical fiber, a wide annular core optical fiber, an annular core optical fiber, a gradient refractive index multimode optical fiber, a large-core-diameter step multimode optical fiber and a light receiving single-mode optical fiber which are connected in sequence. The wide annular core optical fiber comprises a third quartz cladding and a third quartz fiber core, and the third quartz fiber core annularly wraps a third quartz layer; the annular core optical fiber comprises a fourth quartz inner wrapping layer, a fourth quartz fiber core and a fourth quartz outer wrapping layer, the fourth quartz inner wrapping layer is annularly wrapped by the fourth quartz fiber core, the fourth quartz fiber core is annularly wrapped by the fourth quartz outer wrapping layer, and the optical fiber radial refractive index distribution index of the gradient refractive index multimode optical fiber is 1.95-2. According to the scheme, the annular core optical fiber is used for injecting light to the gradient refractive index multimode optical fiber, two modes with smaller group velocity dispersion difference can be excited to interfere, and the sensitivity of the sensor is improved.

The present application relates to a kind of equal optical path adjustment and detection system and method for unpolarized light splitting prism, equal optical path adjustment and detection system includes adjusting mechanism, fixed base, wide spectrum light source, first wedge optical flat, second wedge optical flat, first confocal distance measuring module, second confocal distance measuring module and interference detection component;The plane of first wedge optical flat is towards the first exit surface of first half prism;The plane of second wedge optical flat is towards the exit surface of second half prism;The measuring end of first confocal distance measuring module is towards the inclined plane of first wedge optical flat;The measuring end of second confocal distance measuring module is towards the inclined plane of second wedge optical flat.The present application establishes external optical reference surface by two pieces of wedge optical flat, independently measures air gap of wedge optical flat and corresponding half prism by combining first confocal distance measuring module and second confocal distance measuring module respectively, makes air optical path difference zero, eliminates group velocity dispersion mismatch.

The invention discloses a quantum dot optical frequency comb repetition frequency multiplication system and method based on the time Talbot effect. The quantum dot optical frequency comb repetition frequency multiplication system comprises a quantum dot optical frequency comb source and a Talbot dispersion regulator. The optical frequency comb source generates an input optical frequency comb with repetition frequency; and the dispersion regulator calculates and applies a target total second-order group velocity dispersion amount meeting a fractional order time Talbot phase condition according to a preset integer multiplication factor N, so that the input optical frequency comb generates coherent time domain self-imaging and then forms an output optical frequency comb with repetition frequency. And multiplication is realized only through passive dispersion regulation and control, a high-speed active modulator is not needed, the energy efficiency is high, the structure is simple, and different high repetition frequency requirements of 200GHz and above can be met.

A laser device and control method provide mode-hopping-free laser wavelength (frequency) tuning over a wide frequency band of the gain bandwidth of the gain medium, and possibly the entire gain bandwidth of the gain medium. In general, the apparatus and method include reverse dispersion to compensate for wavelength dependent group delay and group velocity dispersion within the laser cavity to achieve broadband mode hopping free wavelength tuning.

This invention proposes a valley-slow optical waveguide state based on a triangular lattice valley photonic crystal to address the technical problems of weak magneto-optical effect in the optical band and the need for an external strong bias magnetic field in valley-slow optical waveguide states constructed with magneto-optical photonic crystals, as well as the complex fabrication and narrow bandwidth of valley-slow optical waveguide states constructed with honeycomb topological valley photonic crystals. This invention includes a triangular lattice valley photonic crystal with a valley count of 1 and a triangular lattice valley photonic crystal with a valley count of -1. The region formed by the triangular lattice valley photonic crystal with a valley count of 1 is the first region, and the region formed by the triangular lattice valley photonic crystal with a valley count of -1 is the second region. A mustache-shaped interface is formed at the junction of the first and second regions, and a light source is located on the mustache-shaped interface. This invention has advantages such as simpler construction, lower R&D cost, high refractive index, and zero group velocity dispersion, greatly improving the time and intensity of light-matter interaction in waveguide photonic devices, and can be used in integrated photonic devices.

The invention provides an Airy pulse time domain evolution trajectory regulation and control method based on liquid crystal orientation design, and relates to the technical field of ultrafast optics. The method comprises the following steps: firstly, constructing a theoretical model of Airy pulse transmission in a liquid crystal medium, and establishing a nonlinear mapping relation between a liquid crystal molecular orientation angle and group velocity dispersion and a nonlinear mapping relation between the liquid crystal molecular orientation angle and third-order dispersion; establishing a polynomial function relationship between the dispersion parameter and the trigonometric function term of the liquid crystal molecular orientation angle by utilizing numerical fitting based on the mapping relationship; designing a spatial distribution rule of liquid crystal molecules along a propagation direction according to the target time domain trajectory, and determining dispersion distribution in a liquid crystal medium by establishing linear correlation between trigonometric function terms and propagation distances; and finally, carrying out orientation arrangement on the liquid crystal molecules. The spatial orientation gradient of the liquid crystal is designed, a dynamic dispersion environment is constructed on a transmission path, and accurate linear regulation and control of self-acceleration, self-deceleration and track bending degree of the Airy pulse are achieved.

The application discloses an on-chip supercontinuum light source based on a cascade polarized ferroelectric material and a design method thereof. The application comprises: a pump light source for providing pump light; the pump light is incident to a supercontinuum generation waveguide; the supercontinuum generation waveguide satisfies that group velocity dispersion is close to 0 at the wavelength of the pump light, group velocity mismatch of the pump light wavelength and the frequency-doubled light wavelength is close to 0, and the polarization period of the supercontinuum generation waveguide satisfies phase matching of frequency doubling. The polarization period of the supercontinuum expansion waveguide varies along the propagation direction, and the supercontinuum expansion waveguide outputs supercontinuum. A tapered transition waveguide is used to connect the supercontinuum generation waveguide and the supercontinuum expansion waveguide and eliminate the mode mismatch between the supercontinuum generation waveguide and the supercontinuum expansion waveguide. The system of the application has the advantages of low cost, high integration and wide spectral coverage, and is suitable for fields such as environmental monitoring, medical diagnosis and spectral analysis.