DEVICE AND METHOD OF MEASURING SPECTRAL CHARACTERISTICS OF FIBER-OPTIC BRAGG GRATINGS Russian patent published in 2019 - IPC G01J3/18 H04B10/71 

FIELD: optics.

SUBSTANCE: group of inventions relates to fiber optics. Device for measuring spectral characteristics of fiber-optic Bragg gratings includes a semiconductor laser with a built-in heating-and-cooling element. Inputs of heating-cooling device and current source connected to laser semiconductor structure (SCS) are connected to control outputs of control and control unit. SCS via voltage amplifier is connected to circuit for measuring voltage drop on laser SCS realized by control and monitoring unit. Optical coupler and circulator, which is built-in between optical coupler and fiber-optic Bragg grating (FBG), are connected by means of fiber-optic lines to photodetectors, outputs of photodetectors are connected to inputs of amplifiers, outputs of which are connected to measuring inputs of control and monitoring unit. Method of measuring spectral characteristics of fiber-optic Bragg gratings involves changing the wavelength of laser radiation by changing the temperature of laser SCS. At that, voltage drop at SCS is measured and laser emission wavelength is determined by one and more normalizing curves in the form of laser radiation wavelength dependences of laser radiation against voltage drop at laser SCS, previously measured under conditions of temperature change of SCS in constant current mode through SCS and constant temperature of SCS, FBG is irradiated, optical signals of the laser and the reflected FBG signal are transformed with two photodetectors and the FBG spectrum is determined by normalizing the FBG signal to the emitting laser signal.

EFFECT: technical result consists in enabling increase in the FBG spectral characteristics measurement accuracy.

2 cl, 5 dwg