5 results about "Fiber optic interferometer" patented technology

This invention relates to the field of geostress measurement, specifically to a geostress monitoring instrument for soft rock areas based on fiber optic technology. The instrument includes: a cylindrical outer shell with a first through-hole along its length, the outer shell having a uniform thickness throughout; a central column positioned along the center of the first through-hole; a base; a top cover; a thermometer mounted on the central column; an azimuth gauge mounted on the central column; a fiber optic sensor tray mounted on the central column; a fiber optic interferometer probe mounted on the fiber optic sensor tray; and a fiber optic cable, one end of which passes through the inner side of the central column and connects to the azimuth gauge, thermometer, and fiber optic interferometer probe, while the other end is externally connected to an optical signal modem. This invention addresses the problems of existing geostress monitoring instruments, such as large measurement errors, unclear measured physical quantities, short probe lifespan, and difficulty in adapting to complex underground environments.

This invention provides a flexible micro / nano fiber optic multiplexed chip and its monitoring system and method, belonging to the field of biomedical sensing technology. It includes: a myocardial marker detection layer with an embedded array of micro / nano fiber optic interferometers modified with different biological probes for simultaneous detection of multiple cardiovascular disease markers in sweat; a microfluidic channel layer with microfluidic channels for collecting and transmitting sweat and an outlet for sweat excretion; and a pulse wave monitoring layer with an embedded U-shaped micro / nano fiber for real-time pulse wave monitoring based on the bending loss principle, with a localized microfluidic channel inlet for sweat collection. Through the above technical solution, dual-modal multi-information synchronous monitoring is achieved, with high performance and high reliability.

The application discloses a fiber-optic gyroscope and a comb pulse error suppression system and method. The fiber-optic gyroscope comprises a wide-spectrum light source, a fiber-optic interferometer, an electro-optic intensity modulator, a photoelectric detector and a signal processing circuit. The wide-spectrum light source is used to provide a wide-spectrum light signal to the fiber-optic interferometer. The fiber-optic interferometer is used to generate at least one light interference signal according to the wide-spectrum light signal and mechanical rotation. The electro-optic intensity modulator is used to suppress the comb pulse of the light interference signal according to at least one modulation signal. The photoelectric detector is used to generate an electric measurement signal according to the light interference signal after suppression. The signal processing circuit is used to modulate the waveform of the wide-spectrum light signal propagating reversely in the fiber-optic interferometer according to the electric measurement signal, and generate the modulation signal according to the electric measurement signal. The signal processing circuit is used to obtain the rotation information of the mechanical rotation according to the electric measurement signal. The embodiment of the application suppresses the influence caused by the comb pulse error from the root by improving the electro-optic intensity modulator and the signal processing circuit, expands the effective sampling interval of the light interference signal, and suppresses the zero-bias error caused by the demodulation of the electric measurement signal.

This invention discloses a parallel cascaded refractive index sensor and a refractive index detection method based on the vernier effect. The device includes: single-mode fiber L1 and single-mode fiber L2, connected in parallel; the polymer coating layer of single-mode fiber L1 is stripped; both single-mode fiber L1 and single-mode fiber L2 have two semi-circular bends, which do not satisfy the total internal reflection condition; the method includes: immersing the upstream bend of single-mode fiber L1 into the liquid to be tested, and acquiring the wavelength shift data of the trough of the spectral line; based on the wavelength shift data, determining the refractive index of the liquid to be tested from a preset wavelength shift-refractive index relationship curve. This invention uses the bending of single-mode fiber to create a refractive index sensor, utilizing the phenomenon that changes in external refractive index cause a shift in the transmission spectral line, and amplifying the shift using the vernier effect principle to construct a fiber optic interferometer sensing structure, thereby achieving the purpose of high-sensitivity measurement of refractive index.

This invention belongs to the field of fiber optic sensing and recognition technology, specifically an object shape recognition system based on machine learning and fiber optic microphone arrays. The system includes a measurement optical path based on a single-core feedback Sagnac fiber optic interferometer, a microphone array sensor composed of multiple fiber optic coils (a component of the optical path), an obstacle movement device, a sound source, and a signal processing unit. By sensing sound signals through the fiber optic microphone array and extracting time-frequency features using a short-time Fourier transform algorithm, combined with a ResNet50 convolutional neural network or a support vector machine (SVM) algorithm, it achieves the recognition of obstacles of different shapes and types in the sound field. This system possesses advantages such as strong anti-electromagnetic interference capability, high sensitivity, low distortion over long distances, small size, and high recognition accuracy.