41results about How to "Large free spectral range" patented technology

The invention discloses an optical fiber FP air pressure sensor with optical vernier effect and a preparation method thereof. The sensor comprises a single-mode optical fiber, a quartz capillary and a photonic crystal optical fiber. The two ends of the quartz capillary are respectively connected to the respective ends of the single-mode fiber and the photonic crystal fiber by fusion; the other end of the photonic crystal fiber is directly connected to the outside world, and its hole structure is convenient for the outside gas to enter the fiber optic FP sensor. In the cavity, the quartz capillary and the photonic crystal fiber form two Fabry-Perot resonant cavities with vernier effect. A commercial optical fiber fusion splicer is used for preparation, the discharge time and intensity of the electrodes are well controlled to cascade the two types of optical fibers and the optical fiber is cut using a precision cutting device, and the length of the optical fiber is strictly controlled to produce a vernier effect. The optical fiber FP air pressure sensor of the invention has the advantages of small volume, simple preparation, strong adaptability, high sensitivity and wide application prospect.

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 an infinite impulse response microwave photon filter and a filtering method. The infinite impulse response microwave photon filter comprises a multi-longitudinal mode fiber laser used as a light source to provide a light carrier, a polarization controller, an intensity modulator, a fiber loop and a photoelectric detector. The polarization controller regulates the polarization state of the light carrier to enable the light carrier to enter the intensity modulator, the intensity modulator works on a linear region by regulating the polarization voltage of the intensity modulator, microwave signals are modulated to the light carrier, optical signals achieve light splitting at the fiber loop, multi times of delaying and sampling are achieved on the light carrier bearing the microwave signals, the microwave signals with specific frequency are filtered, and the photoelectric detector detects the microwave signals through photovoltaic conversion to filter the light carrier. According to the filter and the filtering method, a large Q value can be provided, and a large free spectrum range is achieved due to the fact that the fiber loop can be very short.

The invention provides a multichannel feedback based Brillouin gyroscope, comprising a narrow line width laser source, an erbium-doped optical fiber amplifier, a first opto-isolator, a second opto-isolator, a 50: 50 coupler, a 90: 10 coupler, a multistage single mode optical fiber, a multimode optical fiber, a Perot filter and a photoelectric converter. The output terminal of the narrow line width laser source is connected with the input terminal of the erbium-doped optical fiber amplifier via the first opto-isolator, the output terminal of the erbium-doped optical fiber amplifier is connected with the input port of the 50: 50 coupler via the second opto-isolator, the two output ports of the 50: 50 coupler are respectively connected with the two coupling ports of the 90: 10 coupler by virtue of an optical fiber, the two through ports of the 90: 10 coupler are connected with the multistage single mode optical fiber and the multimode optical fiber, thus forming a resonant ring, the other output port of the 50: 50 coupler is connected with the input terminal of the Perot filter via an optical fiber, and the output terminal of the Perot filter is connected with the input terminal of the photoelectric converter.

The invention discloses a V-shaped coupled cavity double-wavelength semiconductor laser with continuously adjustable frequency interval. The first active resonant cavity and the second active resonant cavity are coupled in a V-shape at one end to form a multimode coupling region, the end face of the multimode coupling region has a cavity surface reflection surface, the other end of the first active resonant cavity and the first passive The source filters are connected in series through deep etched grooves to form one arm of the laser; the other end of the second active resonator and the second passive filter are connected in series through deep etched grooves to form the other arm of the laser; the first active Shallow etching grooves are arranged on the resonant cavity and the second active resonant cavity. The laser of the invention has the advantages of compact structure, simple manufacturing process, low cost, no external reference light source and the like.

The invention discloses an optical waveguide ring resonator based on an asymmetric directional coupler, which is applied in the fields of optical communication, optical information processing, and optical sensing to realize functions such as wave filtering, delay, and sensing, and includes a backbone waveguide, a multimode Waveguide and ring waveguide, backbone waveguide and multimode waveguide constitute an asymmetric directional coupler, which can realize multiple ring waveguide resonators coupled to the backbone waveguide at the same time, so that the vernier effect can be used to increase FSR and realize high-performance ring resonator , its structure is easy to expand. By designing different asymmetric couplers, the number of ring resonators used can be extended from two to three, or even more, and the size of the device will not increase significantly. The ring resonator has a compact structure, can achieve high performance with a small size, and further promotes the application of the ring resonator in the fields of optical communication, optical information processing, and optical sensing, and provides important technical support for the above fields. Greater application value.

The invention discloses a liquid crystal tunable filter and a configuration method thereof. The filter includes several cascaded Leo configuration filter units, and the Leo configuration filter unit consists of polarizers on both sides and a middle A birefringent optical element is formed, wherein part or all of the Leo configuration filter units are combined in two consecutive cascades or three consecutive cascades to form a combined unit. The merge method is stacked or fan merged. The birefringent optical element is a liquid crystal tunable wave plate, a fixed wave plate or a combination of a liquid crystal tunable wave plate and a fixed wave plate. The liquid crystal tunable filter of the present invention has the advantages of high pass rate, narrow half-width, high shielding rate, adjustable spectral range, strong stability, no need for mechanical rotation, and real-time controllable advantages. It can be widely used in Imaging, biology, medicine, materials, optics, optoelectronics, astronomy and other fields.

The invention relates to the technical field of optical fiber sensing, in particular to a silicon-core optical fiber-based Fabry-Perot sensor and a preparation method thereof. The Fabry-Perot sensor based on silicon core optical fiber of the present invention comprises ordinary single-mode optical fiber, optical fiber fusion joint end face, silicon core optical fiber and polishing end face, forms fusion joint end face after input optical fiber and silicon core optical fiber fusion, silicon core optical fiber is made of silicon core optical fiber The cladding is composed of the silicon core optical fiber core, the end face of the silicon core optical fiber is polished to form a polished end face, and the fusion end face and the polished end face form two mirror surfaces of the Fabry-Perot cavity of the silicon core optical fiber. The silicon core optical fiber Fabry Perot sensor obtained by the invention has high temperature sensitivity, laser power sensitivity and response speed, and the invention also has the advantages of simple structure, easy manufacture, good repeatability and the like.