A fiber Bragg grating strain sensor,whose reflection bandwidth is insensitive to temperature,is presented.The cross-sec-tional area is designed to change linearly.Under axial stress,there is a linear relationship betw...A fiber Bragg grating strain sensor,whose reflection bandwidth is insensitive to temperature,is presented.The cross-sec-tional area is designed to change linearly.Under axial stress,there is a linear relationship between stress and average strain.Experimental results show that when temperature increases,reflection center wavelength shifts to longer wavelength,and there is a good linear relationship between center wavelength and temperature.When stress increases,reflection center wavelength shifts to longer wavelength,and reflection bandwidth increases.There are good linear relationships between reflection center wavelength and stress as well as reflection bandwidth and stress.展开更多
This paper describes a new method to design a laser mirror with high reflectivity, wide reflection bandwidth and high laser-induced damage threshold. The mirror is constructed by three materials of HfO2/TiO2/SiO2 base...This paper describes a new method to design a laser mirror with high reflectivity, wide reflection bandwidth and high laser-induced damage threshold. The mirror is constructed by three materials of HfO2/TiO2/SiO2 based on electric field and temperature field distribution characteristics of all-dielectric laser high reflector. TiO2/SiO2 stacks act as the high reflector (HR) and broaden the reflection bandwidth, while HfO2/SiO2 stacks are used for increasing the laser resistance. The HfO2/TiO2/SiO2 laser mirror with 34 layers is fabricated by a novel remote plasma sputtering deposition. The damage threshold of zero damage probability for the new mirror is up to 39.6 J/cm2 (1064 nm, 12 ns). The possible laser damage mechanism of the mirror is discussed.展开更多
基金supported by the National Natural Science Foundation of China(Nos.60837002and61177069)the Ph.D.Programs Foundation of Ministry of Education of China(No.20090009110003)the Fundamental Research Funds for the Central Universities(No.2011YJS214)
文摘A fiber Bragg grating strain sensor,whose reflection bandwidth is insensitive to temperature,is presented.The cross-sec-tional area is designed to change linearly.Under axial stress,there is a linear relationship between stress and average strain.Experimental results show that when temperature increases,reflection center wavelength shifts to longer wavelength,and there is a good linear relationship between center wavelength and temperature.When stress increases,reflection center wavelength shifts to longer wavelength,and reflection bandwidth increases.There are good linear relationships between reflection center wavelength and stress as well as reflection bandwidth and stress.
基金supported by the National Natural Science Foundation of China (No.50802080)the Natural Science Foundation of Fujian Province of China (No.2010J01349)
文摘This paper describes a new method to design a laser mirror with high reflectivity, wide reflection bandwidth and high laser-induced damage threshold. The mirror is constructed by three materials of HfO2/TiO2/SiO2 based on electric field and temperature field distribution characteristics of all-dielectric laser high reflector. TiO2/SiO2 stacks act as the high reflector (HR) and broaden the reflection bandwidth, while HfO2/SiO2 stacks are used for increasing the laser resistance. The HfO2/TiO2/SiO2 laser mirror with 34 layers is fabricated by a novel remote plasma sputtering deposition. The damage threshold of zero damage probability for the new mirror is up to 39.6 J/cm2 (1064 nm, 12 ns). The possible laser damage mechanism of the mirror is discussed.
