9 results about "Fiber optic coupler" patented technology

The application discloses a kind of spectrometer performance calibration devices for frequency domain OCT system, include: two groups of calibration light path components, light source drive board and fiber coupler;Two groups of calibration light path components are connected to fiber coupler;Fiber coupler is connected to light source drive board;Calibration light path component includes: six-dimensional adjustment frame, installation lens barrel, corner cube, optical flat, two-dimensional adjustment frame, collimating lens and collimating adjustment frame;Corner cube is installed to installation lens barrel;Installation lens barrel is connected to six-dimensional adjustment frame;Optical flat is installed to two-dimensional adjustment frame;Collimating lens is installed to collimating adjustment frame;Collimating adjustment frame is equipped with fiber connection part;Two-dimensional adjustment frame is between installation lens barrel and collimating adjustment frame.This application's spectrometer performance calibration device for frequency domain OCT system, simple structure can obtain signal-to-noise ratio with depth variation curve and other performance indicators, judge spectrometer assembly and debugging result, improve instrument consistency.

This invention discloses a miniature beam-splitting optical path system for atomic interferometry, comprising a main optical path and primary and secondary reflection sub-paths. Laser light is input into the main optical path after purification and polarization, and then split by a half-wave plate and a polarizing beam-splitting prism. The split beam consists of a primary reflection and a secondary reflection generated by the secondary reflection, which passes sequentially through a quarter-wave plate and a 0° mirror and re-enters the polarizing beam-splitting prism. The primary and secondary reflections then enter their respective sub-paths for further splitting. Independently adjustable right-angle prisms and polarizing beam-splitting prisms within the sub-paths eliminate the influence of the incident direction of the light entering subsequent optical paths. This miniature beam-splitting optical path system and method can output multiple laser beams with consistent polarization, adjustable power and frequency. It can be input and output via fiber optic couplers, and is suitable for atomic interferometry and other fields. It improves the efficiency of laser energy utilization and the stability of laser parameters, easily maintains symmetrical optical path distribution, and enhances system integration.

This invention discloses an experimental method for measuring the electron-hole recombination emission rate. The apparatus for this method includes a laser chip (with an anti-reflection coating on only one end of its horizontal two-sided end face), a plano-convex lens, a polarizer, a fiber optic coupler, an optical fiber, and a spectrometer. The plano-convex lens, polarizer, plano-convex lens, and fiber optic coupler are placed sequentially on the same horizontal line on both sides of the chip. The fiber optic coupler is connected to the spectrometer via an optical fiber. First, energy is applied to the laser chip, causing it to emit light from both sides. The spectra from both sides are focused onto the fiber optic coupler by the plano-convex lens and then transmitted to the spectrometer via the optical fiber. By rotating the polarizer, different polarization spectra can be selected to obtain specific spectral images under transverse electric / magnetic field modes. Finally, by substituting the spectral data from both ends into the established formula, the electron-hole recombination rate of the laser chip can be calculated.

This invention specifically relates to a refractive index measurement system and method based on fiber optic interferometry, used for real-time monitoring of the refractive index of transparent gases and liquids. It addresses the technical problems of existing air refractive index measurement methods, which either struggle to accurately obtain the absolute value of the refractive index, or involve complex procedures, cumbersome optical path adjustments, susceptibility to vibration interference, and low dynamic response speed. The fiber optic interferometry-based refractive index measurement system includes a tunable fiber laser, a first fiber coupler, a transmitting probe, a receiving probe, an attenuator, a second fiber coupler, a photoelectric converter, and a recording device. The first fiber coupler splits the optical signal emitted from the tunable fiber laser into two paths, one input to the transmitting probe and the other to the attenuator. The input of the second fiber coupler is connected to the output of the attenuator and the output of the receiving probe. This invention offers high reliability and a fast response time of 0.2 ms; it can perform refractive index monitoring in various scenarios.

The application provides a near-earth optical communication turbulence suppression system and method based on emission source gain regulation, which comprises a host computer and a slave computer, and each comprises a space-fiber coupler, a PSD position detector, a PSD demodulation and control assembly, a communication transmitter-receiver, an electrically-controlled optical attenuator, a stepping actuator and a beacon light emitter; the space-fiber coupler aligns and matches the emitted light with the receiving field of view and couples the space light to the optical fiber; the beacon light emitter emits service beacon light; the PSD position detector performs real-time position detection on the light spot of the service beacon light; the PSD demodulation and control assembly calculates the off-target amount of the light spot position of the service beacon light and its control amount output to the stepping actuator, demodulates the service beacon text data and transmits it to the communication transmitter-receiver; the electrically-controlled optical attenuator regulates the emitted light power of the communication transmitter-receiver; and the communication transmitter-receiver controls the voltage value of the electrically-controlled optical attenuator based on the service beacon text data to realize closed-loop gain control and turbulence suppression from the receiving end to the transmitting end.

The application relates to a fluorescence detection device and a crystallization state detection system, the fluorescence detection device comprising a pulsed light signal source, a fiber coupler and a fluorescence detector; the pulsed light signal source comprises at least two signal output ends for outputting pulsed light signals of different frequencies, one of the at least two signal output ends is connected with the fiber coupler through a first optical fiber, and the other signal output ends are connected with the fiber coupler through a delay unit; the delay unit is used for generating a delay between the pulsed light signals of different frequencies; the fluorescence detection device utilizes the delay unit to make the fiber coupler output light signals of different frequencies, i.e. combined wave signals, after coupling, so as to realize detection of different depths of a sample to be detected by utilizing the combined wave signals of different frequencies in time sequence, and improve the detection comprehensiveness.

This invention discloses a high signal-to-noise ratio (SNR) performance enhancement system based on BOTDR, relating to the field of distributed fiber optic sensing technology. It includes an optical path unit and a circuit processing unit. The optical path unit comprises a narrow-linewidth laser (Laser), a pulse modulation module, a variable optical attenuator (VOA), a hierarchical optical amplification module, an optical circulator (OC), a polarization scrambler (PS), and a fiber coupler array. The circuit processing unit includes a photodetector pre-amplifier module, a low-noise amplifier, a frequency mixer and down-conversion module, and a frequency selection module. This BOTDR-based high SNR performance enhancement system significantly improves the system's SNR and monitoring accuracy through optimized optical path and circuit structure design, precise selection of core optical components, and innovative optical signal processing links. Through an integrated design of 1550nm band narrow-linewidth continuous optical modulation, hierarchical precise amplification, polarization state optimization, and efficient coherent beat frequency, noise in the Brillouin scattering signal is effectively suppressed during transmission and detection, resulting in a significant improvement in signal strength.

This invention provides a laser synthesis wavelength measurement interferometer based on optimized fiber coupling. The interferometer includes: a composite laser source, a fiber coupler assembly, a fiber beam splitter assembly, a polarization beam splitter assembly, an adjustable optical path reference fiber, an adjustable optical path measurement fiber, a photodetector assembly, and an electronic control system, all interconnected. The composite laser source emits two laser beams with wavelengths λ1 and λ2 respectively. The fiber coupler assembly includes a first fiber coupler, a second fiber coupler, and a third fiber coupler. The fiber beam splitter assembly includes a first fiber beam splitter and a second fiber beam splitter. The polarization beam splitter assembly includes a first polarization beam splitter and a second polarization beam splitter. The photodetector assembly includes a first photodetector, a second photodetector, and a third photodetector. This invention improves the measurement accuracy of the interferometer, and damaged parts of the interferometer can be replaced individually, facilitating maintenance by repair personnel.