38results about How to "Light path structure is simple" patented technology

A multi-channel fiber bragg grating absolute wavelength demodulation system based on a single detector comprises a broadband light source, a circulator, reference fiber bragg gratings, a 1*N optical switch, N-path sensing fiber bragg grating arrays, a tunable filter, a photoelectric detector and a data acquisition card. The invention simultaneously provides a demodulation method based on the system. The method is characterized in that the broadband light source generates light; the light passes through the circulator, then passes through the two reference fiber Bragg gratings and then is divided into transmission light and reflected light; the transmission light enters into the 1*N optical switch; a gating signal generated by the data acquisition card makes the light enter into a corresponding sensing fiber bragg grating channel; the reflected light enters into the tunable filter via the circulator; reflected light of a sensing fiber bragg grating also enters into the tunable filter via the circulator; frequency sweeping light is received by the photoelectric detector; a spectrum signal is converted into a time domain signal; then demodulation is performed so that a relative position of the reference fiber bragg gratings and the sensing fiber bragg grating is acquired. By using the system and the method of the invention, the system structure can be simplified and a wavelength measurement error caused by optical fiber transmission is eliminated.

The invention discloses a method for compensating for the intensity of a differential pressure sensor. The method is characterized in that two light sources are adopted to alternately emit light, two detection probes of the same structures are adopted to carry out detection, a Y-type coupler couples or separates light paths, then the ratios between pressure values of the two detection probes and a reference light path are calculated, and arithmetical operation is carried out on the ratios, so errors produced by fluctuation of the light sources are eliminated. The light bridge type layout mode is adopted in the light paths, the reference light paths of the two light sources pass through the Y-type coupler to reach the same photoelectric detector, reflection light receiving light paths of the two detection probes reach another photoelectric detector through the Y-type coupler, therefore, the integral light path structure of the sensor is simplified, layout of optical fibers of the light paths can be simple, meanwhile the number of the detectors is reduced, and a later data processing module is simplified. Finally, economical and reliability design is achieved.

The invention belongs to the field of optical fiber technology, and specifically relates to a multi-path optical path correlator with adjustable resonant cavity length that can be used in a demodulation system of multiplexed optical fiber white light interference sensor array. The present invention connects an optical resonant cavity to the optical fiber optical path through a coupler, adjusts the length of the resonant cavity and passes through multiple round trips of the optical path, and consists of an optical path adjustable optical resonant cavity, a fiber optic coupler, and a three-port or four-port optical fiber ring The optical resonant cavity oscillates back and forth to generate adjustable multi-channel optical path difference signals; the coupler outputs the optical signal containing multiple optical path differences; the three-port circulator controls the direction of the optical signal, and passes through the optical fiber The connection of the light path of the white light interference system. The multi-path optical path correlator provided by the present invention realizes the optical path matching of multiple optical paths, enhances the demodulation ability of the sensing system, simplifies the optical path structure of the optical system, reduces the cost of the system, and improves the stability of the system and reliability.