Electro-optical modulator operating point locking device and locking point detecting method with adaptive capability

Abstract

The invention discloses an electro-optical modulator operating point locking device and a locking point detecting method with adaptive capability. The electro-optical modulator operating point lockingdevice comprises an electro-optical modulator, a coupler, a sinusoidal signal generating circuit, an attenuator, an amplifier, a DAC (digital to analog converter), an adder, an optical detection circuit, a multiplier, a low-pass filter and a single chip microcomputer. The invention further discloses an electro-optical modulator operating point locking method with adaptive capability. Through detecting part of output light of the electro-optic modulator, the electro-optical modulator operating point locking device and the locking point detecting method realize the control over the bias voltageof the electro-optic modulator, and lock the operating point of the electro-optic modulator at the optimal operating point.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to an electro-optic modulator operating point locking device with self-adaptive capability and a locking point detection method. Background technique [0002] Brillouin Optical Time Domain Reflectometry (BOTDR) technology has been widely concerned since it was proposed by T.Kurashima et al. in 1993, especially in recent years, it has developed rapidly. BOTDR technology uses the Brillouin backscattered light in the optical fiber to be sensitive to temperature and strain and has a linear relationship. By detecting the Brillouin backscattered light in the optical fiber, the temperature and strain along the optical fiber can be detected. Due to the BOTDR The technology has the advantages of long measurement distance and high spatial resolution, and can accurately locate and identify faults and hidden dangers in the optical fiber detection area. It shows broad prospects in...

AI Technical Summary

Problems solved by technology

In the above two lock-in methods based on the principle of lock-in amplification, large-scale equipment such as oscilloscopes, lock-in amplifiers, computers, etc. are required, and the cost is relatively high, and automatic feedback control cannot be realized, which is very inconvenient in practical applications. The photodetection circuit used is a DC photodetection circuit with low magnification, resulting in low locking accuracy

In the self-heterodyne coherent detection BOTDR system structure, the functions of the two electro-optic modulators are different, and the working point locking methods are usually different. Two kinds of working point locking devices with different structures are required to lock the working points of the two electro-optic modulators. , resulting in a complex overall circuit that is not easy to integrate

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