An optical fiber characteristic measurement device (1) includes: a first optical splitter (12) that splits frequency-modulated modulated light (L1) into pump light (LP) and reference light (LR); a second optical splitter (16) that causes the pump light to be incident from one end of an optical fiber under test (FUT) and outputs Brillouin scattered light (LS) generated inside the optical fiber under test; a first detector (19) that detects interference light between the Brillouin scattered light output from the second optical splitter and the reference light; an analyzer (20) that obtains a Brillouin gain spectrum which is a spectrum of the Brillouin scattered light from a detection signal (S1) output from the first detector; a second detector (22, 31) that detects a double wave component having a frequency that is double a modulation frequency of the modulated light included in an intensity component of each frequency of the Brillouin gain spectrum obtained by the analyzer; and a measurer (23) that measures characteristics of the optical fiber under test on the basis of the double wave component detected by the second detector.

An integrated fiber interferometry interrogator for generating superimposed waves is disclosed. The system is optimized for efficiency and vibration attenuation. The system comprises an optical light source for generating a first signal, a first signal splitter which splits the first signal into a reference signal and an interrogation signal, optical modulators for modulating the signals, a fiber coupler connected to a fiber under test, an isolator, a circulator with a plurality of connections for directing the signals, a signal mixer for mixing the signals into superimposed waves, and photo diodes for receiving the superimposed waves.

A modular fiber optic interferometry control system and method for extracting information from superimposed waves is disclosed. The system comprises a first module for converting a radio frequency input to a multiplexed binary data stream, a second module for correlating a pseudo random number (PRN) reference with a received PRN code modulated backscattered signal, and a third module comprising control logic. In some embodiments the system further comprises one or more of a fourth module for generating a power stream, a fifth module for event interrogation, and a sixth module for noise reduction.

An optical fiber characteristics measurement apparatus (10) according to the present disclosure measures the characteristics of an optical fiber. The optical fiber characteristics measurement apparatus (10) includes a laser light source module (11) that outputs frequency-modulated laser light. The laser light source module (11) includes a laser light source (110) that outputs laser light, a laser light source driver (111) that modulates the frequency of the laser light outputted by the laser light source (110), and an optical amplifier (116) that adjusts the amplitude of the frequency-modulated laser light outputted by the laser light source (110) so as to cancel an amplitude modulation occurring in the frequency-modulated laser light outputted by the laser light source (110).

A method of optical sensing is disclosed. The method comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal; coupling the backscattered signal into a second optical fiber, spatially separated from the first optical fiber; and optically amplifying the backscattered signal in the second optical fiber, thereby generating a sensing signal.

The present invention relates to a distributed sensing optical fiber performance multi-objective multi-degree-of-freedom static and dynamic test integrated platform and a test method. Wherein an optical fiber multi-degree-of-freedom fixing system is sequentially connected with an artificial loading and unloading device and an oil pressure control loading and unloading device, and an optical fiber under test is connected with the optical fiber multi-degree-of-freedom fixing system and a distributed optical fiber Brillouin frequency shift acquisition system; and test on performance of optical fiber is achieved by controlling devices in the optical fiber multi-degree-of-freedom fixing system. The device of the present invention has a large number of advantages such as a simple structure, a low cost, convenient operation, less disturbance, many test classes, strong adaptability, stable performance and convenient loading and unloading.

An apparatus and a method for transmission of optical signals. The apparatus includes a bidirectional amplification device communicatively coupled between a first communication terminal and a second communication terminal. The first and second communication terminals are communicatively coupled using an optical communication link. The bidirectional amplification device is configured to transmit and amplify one or more optical sensing signals transmitted in either direction between the first communication terminal and the second communication terminal. The optical sensing signals indicate a status of one or more portions of the optical communication link.

An optical fiber characteristics measurement apparatus includes a first optical splitter that splits modulated light into pump light and reference light, a second optical splitter that causes the pump light to be incident on a fiber under test from one end and extracts Brillouin scattered light generated within the fiber under test, an adjuster that changes frequency of at least one of the reference light and pump light to a plurality of frequencies, and a calculator that measures characteristics of the fiber under test based on a second harmonic component among frequency components of a signal yielded by homodyne detection of interference light between the Brillouin scattered light and the reference light at each frequency, the second harmonic component having a frequency that is two times the modulation frequency of the modulated light.

An optical fiber measurement system includes an optical time-domain reflectometer, a wavelength division multiplexer, and a signal generator. The signal generator sends a signal light ray to the wavelength division multiplexer. The optical time-domain reflectometer sends two measurement light rays whose wavelengths are respectively longer than and shorter than a wavelength of the signal light ray to the wavelength division multiplexer. The wavelength division multiplexer combines the two measurement light rays and the signal light ray, sends a combined light ray to an optical fiber, and sends a light ray returned by the optical fiber to the optical time-domain reflectometer, so that the optical time-domain reflectometer determines performance of the optical fiber based on the returned light ray.