44 results about "Fiber raman amplifier" patented technology

An object of the present invention is to prevent an interruption circuit of an optical amplifier from malfunctioning due to Raman pump wave. A typical mode of the present invention is characterized in that an pump wave elimination filter is inserted before an input-light detector and a reflected-light detector which constitute the optical amplifier. This permits only a signal component to be detected, enabling interruption operation, while eliminating a remaining component of Raman pump wave transmitted from for example a downstream of an optical fiber transmission line. In addition, a judgment threshold value for the interruption operation is changed according to ON / OFF condition of the pump wave. Or the Raman pump wave itself is used for detecting output's open.

The distributed optical fiber acoustic wave and vibration fusion sensing system of the present invention includes a laser, a 1×2 optical fiber coupler, an acousto-optic modulator, an erbium-doped optical fiber amplifier, a first optical fiber filter, an optical fiber circulator, a first optical switch, Optical fiber Raman amplifier, second optical switch, second optical fiber filter, 3×3 optical fiber coupler, first photodetector, second photodetector, third photodetector, data acquisition and processing unit, computer, host machine software. Advantages: The system combines two sensing functions and modes of vibration and sound wave sensing, which can meet different work requirements, effectively overcome the shortcomings of conventional distributed optical fiber sensing equipment with only single vibration or sound wave sensing, and save costs , is an important technical improvement in the field of distributed optical fiber sensing; it can be flexibly switched according to different usage requirements and scenarios, saving costs and easy to use; it proposes a way to control the optical switch to switch between vibration and acoustic sensing modes, and the operation is flexible.

The invention relates to the technical field of the optical fiber communication, and is a suppression method and system of relative phase noise in a coherent optical fiber Raman amplification system.The method comprises the following steps: step one, a beam splitter receives forward Raman pumping light and performs the light splitting; step two, a transmitting end beam combiner couples 99% of forward Raman pumping light; step three, an optical power meter monitors the power of the 1% of forward Raman pumping light in real time; step four, an optimal value of the optical power is determined through a feedback algorithm; step five, a fiber incident power of the transmitted signal light is regulated; step six, the forward Raman pumping light amplifies the signal light entering the transmission optical fiber; and step seven, a signal receiver receives the signal light. By improving the commercial transmitting end and the forward pumping structure at present, the forward Raman pumping light performs light splitting through one beam splitter, the fiber incident power of the signal light is regulated in real time, the compensation part reduces the noise coefficient of the Raman amplifierdue to the receiving end signal light relative phase noise caused by the forward pumping light power fluctuation.