33results about How to "Polarization stabilization" patented technology

The invention provides a phase encoder / decoder and a quantum key distribution system. The phase encoder / decoder comprises a Sagnac ring structure, that is, the Sagnac ring structure is adopted to replace a back and forth structure for high-speed phase loading, fractions perpendicular to two polarizations of a same pulse pass through a phase modulator for a single time simultaneously, and not onlyis a characteristic of polarization stabilization achieved, but also advantages of high speeds and high efficiency are achieved. According to the phase encoder / decoder, a Faraday-Sagnac-Michelson encoder is adopted as a core phase encoding quantum key distribution system, one-way high-speed safety key distribution can be achieved, and the phase encoder / decoder has the advantages of channel deviation disturbance resistance and high encoding rates are achieved.

The invention discloses a light frequency transmission used all-fiber narrow linewidth fiber laser device and the method thereof. The device of the invention comprises a laser, a first frequency shift device, an isolator, a first Y type coupling device, an X type coupling device, an attenuator, a first Faraday rotating mirror, a second Y type coupling device, a second Faraday rotating mirror, a second frequency shift device, a time-delay fiber, an optical fiber amplifier, a third frequency shift device, a third Faraday rotating mirror, a photoelectric detector, a band pass filter, an oscilloscope, and a frequency synthesizer. According to the invention, under the condition that the frequency discrimination precision of an interferometer is reduced, the length of the time-delay optical fiber could be shortened; the frequency discrimination precision could be increased; the cost can be reduced and the device can be transported.

The invention provides a laser, which comprises at least one pump light emitting device, an optical fiber beam combiner, a grain optical fiber, a first aligner, a mold locking device, a second aligner and an output lens, wherein a first polarization beam-splitting device is arranged between the first aligner and the mold locking device on the laser; a second polarization beam-splitting device is arranged between the second aligner and the output lens on the laser; adjacent optical devices are connected by adopting polarization-preserving optical fibers. The laser having a polarization-preserving optical fiber structure is high in stability. Linearly polarized light is transmitted through the polarization-preserving optical fibers, so that the influence of vibration on a light path caused by temperature change is avoided. Moreover, the mold locking device can be used for stably absorbing a part of energy and reflecting laser pulse generated after stable mold locking through the polarization beam-splitting devices.

The invention is an optic fiber safety prewarning polarization control system of buried tube, construction or important establishment and area. A polarization modulator [202] is between laser [101] and filter [203] which composes Mach-Zehnder fibre-optical interometer with filter [204], optic fiber [1], optic fiber [2], the filter [203] is connected with optoelectronic detector [407], [408], then it is connected with signal process circuit [409], the output of signal process circuit [409] is connected with polarization modulator [202] and polarization controller [201] of the phase modulator [206] connected with optic fiber [1] or [2]. Then the laser [101] is connected with harassing polarimeter [410], then connected with filter [203], the filter [203] is separately connected with checking polarimeter [412], [413], output of thechecking polarimeter [412], [413] is separately connected with input of the polarization detector [407], [408], output of the polarization detector [407], [408] is connected with signal process unit [411].

The invention discloses an infrared controllable partially polarized radiation source, which comprises a temperature controller, a black body, an infrared collimator, an infrared polarizer and a reflector; the temperature controller controls the temperature of the black body, and the black body emits radiation of different wavelengths corresponding to different temperatures Infrared rays; the infrared collimator collimates the infrared rays emitted by the black body; the infrared polarizer turns the collimated infrared rays into linearly polarized radiation; the reflector changes the linearly polarized radiation in two mutually perpendicular vibrations according to the incident angle of the linearly polarized radiation The phase difference in the direction, and reflect and output part of the polarized radiation corresponding to the polarization state. The above-mentioned infrared controllable partially polarized radiation source can produce infrared partially polarized radiation with different polarization states and known polarization parameters, and can generate partially polarized radiation within a large range of polarization degrees. The polarization state of the partially polarized radiation is controllable and the polarization degree is known. , and the degree of polarization is stable and the precision is high under certain environmental conditions, and it is suitable for polarization calibration of infrared polarization imaging systems.

The invention relates to the technical field of integrated optics, in particular to a polarizing device and a preparation method thereof. It includes: a support layer and a mode screening layer, the support layer is used to support the mode screening layer; the mode screening layer includes a light absorption layer and a light isolation layer, and the light absorption layer is arranged on the support layer, The light isolating layer is disposed on the light absorbing layer; the light absorbing layer is used for absorbing light in a preset optical waveguide mode. The light-absorbing layer can selectively absorb light waves of TM mode and other high-order modes, and the light-isolating layer can limit the degree of absorption of light wave energy by the light-absorbing layer. The polarization control of the polarizing device described in this application is based on the improvement of the entire circuit substrate. When the optical structure is integrated on the chip on a large scale, the mode screening layer can polarize the light waves in all the optical structures. Screening, so there is no need to repeatedly prepare a large number of polarization control structures on the optical path, which reduces the difficulty of the process.

The invention provides a laser and a manufacturing method and application thereof. The laser comprises a lifting substrate, a reflecting layer, at least one platform-shaped structure, a plurality of grooves and a second material layer, wherein the lifting substrate comprises a first surface and a second surface which are opposite to each other; the reflecting layer is positioned on the second surface; the at least one platform-shaped structure is positioned on the reflecting layer, and the platform-shaped structure comprises at least two active layers and a first material layer; the pluralityof grooves are formed in the first material layer; the second material layer is located on the first material layer and fills the plurality of grooves; the refractive index of the first material layeris greater than that of the second material layer; a tunnel junction is arranged between the at least two active layers, and each active layer comprises a first semiconductor layer, an active regionand a second semiconductor layer. The laser provided by the invention can improve the current injection efficiency.

The invention discloses an optical fiber depolarizer with a single-mode fiber serving as a delay line. The optical fiber depolarizer comprises an optical fiber branching device, a first polarization beam splitter, the single-mode fiber, a faraday rotary reflector and a second polarization beam splitter. A beam combination port of the first polarization beam splitter and the faraday rotary reflector are connected to two ends of the single-mode fiber respectively to form a delay optical path, and two beam splitting ports of the first polarization beam splitter serve as an input port and an output port of the delay optical path respectively. The optical fiber branching device divides input light into two branches, one branch of light is directly inputted into one of beam splitting ports of the second polarization beam splitter, the other branch of light passes through the delay optical path to be inputted into the other beam splitting port of the second polarization beam splitter, and depolarized light is outputted from a beam combination port of the second polarization beam splitter. Cost of the optical fiber depolarizer is reduced by using the normal single-mode fiber as the delay line; and the polarization state is kept stable after the light passes through the delay optical path, and accordingly the optical fiber depolarizer can operate stably.

The invention relates to a quantum communication system without polarization feedback and a quantum safe direct communication method. The quantum communication system of the invention comprises a communication receiving module, a communication sending module and a quantum channel between the two parties; a first phase modulation in the communication receiving module The device can prepare photons in four random phases for the communication sending module, and obtain qubits by detecting the photons returned by the communication sending module through a single photon detector; the communication sending module includes an encoding optical path module and a security detection module. The invention utilizes the consistency of the coded optical path and the stability of the safety detection optical path to avoid the influence of polarization drift caused by birefringence.