Research On Sensing Properties Of Polymer Long-period Fiber Grating

Optical fiber sensing has great potential in most fields of modern science and technology, such as industrial manufacture, civil engineering, medical and biological technologies etc. The popular optical fiber sensors include rotation, temperature, strain, stress, vibration, acoustic and pressure sensors etc. However, so far the research and development work have been mainly concentrated on silica optical fiber based systems. Polymer optical fiber technology has made remarkable progress in recent years. The application of polymer optical fiber in sensing could be advantageous. A main advantage is its low Young's modulus. The Young's modulus of polymer fiber materials is typically many times less than that of silica glass. This is important feature that makes polymer optical fibers or polymer fiber gratings better candidates for sensing in various liquid and elastic material environments, duly covering a full range of strain-related sensor applications.This paper just focuses on the polymer long period fiber gratings (PLPG), and pays much attention to the temperature, strain sensor with PLPG Beginning with existing commonly used methods in basic theoretical analysis of optical fiber gratings' modes and modes coupling. Meanwhile, introduced the use of FBG and LPG sensor for the measurement of temperature and strain. Analyzed the strain and temperature sensitivities of FBG and LPGThe current criterion of the optical instruments is based on silica fiber. So the coupling for single-mode polymer optical fiber and single-mode silica fiber is required. An auto-coupling system that can implement the function is introduced in this paper.Some experiments are combined in this paper. With facilities in the lab, flats to perform the temperature and strain sensor with PLPG experiments were set up respectively. The mode distribution of PCF was observed and the endless-single-mode trait was proved. The PLPG won a strain sensitivity of 1.144pm/uε with a strain to 1.267% and temperature sensitivity of 56.23pm/℃ . What's more, the FBG's temperature and strain sensor characteristics were comparably studied between PLPG on the same platforms.