FBG based Reflector

1、 Description

     In order to cope with the application oflarge scale (requiring a large number of sensing points) in the engineeringfield, we have launched the sensing fiber project, that is, in the process offiber drawing, a large number of weak gratings with low reflectivity (about 1 /10000 reflectivity) are continuously engraved online, the number of gratingsand the distance between them can be customized according to the actualengineering, and the number can reach tens of thousands Point, from a fewmillimeters to a few meters to tens of meters.

There are two ways to demodulate a weakgrating with such a low reflection. One is based on the OFDR (optical frequencydomain reflectometer) system, which allows fast and accurate measurement in awide range of strain or temperature. The spatial resolution of the whole fiberlength is as low as a few millimeters. The other way is based on the OTDRdemodulating system, which uses the time domain to locate the position and thewide-band light source to demodulate the shift of the wavelength.

Sensing fiber is made by combining fiber drawing and grating writing.The input material for this process is fiber preforms. After heating thepreform, it will begin to stretch and form fibers. In the process of fiberdrawing, the fiber passes through the modulated periodic UV interferenceregion, and the fiber is written and modulated in real time. By controlling thepulse of the laser and combining with the drawing speed, the fiber grating ofpredetermined wavelength can be written accurately in the predeterminedposition. After writing the grating, the fiber is coated by the coating cupcontaining the coating solution, and then the coating is cured. At the sametime, in the production process, the position of the grating is automaticallymarked. The process of drawing fiber, writing grating and coating fiberdirectly after grating lettering can continuously produce high-strength gratingarray and keep the strength of original fiber.

1、Product features

1）No fusion between sensingpoints

2）Supporting mass production

3）Accurate location

4）High product reliability andstability

5）Greatly reduce the overallcost of the sensor system

2、Application

1） Distributed temperaturemeasurement

2） Distributed strainmeasurement

3）Distributed comprehensive parametermeasurement

4）Distributed vibrationmeasurement

5） Wavelength reference

3、Parameters