Zhu Hongna

Gain Improvement of Fiber Parametric Amplifier via the Introduction of Standard Single-Mode Fiber for Phase Matching

We investigate and experimentally demonstrate the gain improvement of single-pump fiber parametric amplifiers by using a suitable length of standard single-mode fiber (SSMF) inserted between two high-nonlinear fibers (HNLFs). The SSMF with different dispersion properties from the HNLF is employed for phase matching of the parametric processes, and the signal gain is improved as compared with the absence of the SSMF with experiment results. Furthermore, the effect of the input pump power and the fiber length of the SSMF on the output signal gain are discussed with experimental investigation.

Composite railway health monitoring system based on fiber optic bragg grating sensing array

During the long-time working circle, railroad transport system will be damaged to a certain degree caused by the wearing, the impact, the loads, the climate and so on. In order to monitor the health of the railways and reduce the potential losses, many effective methods are used in railway health monitoring, but few of the techniques can reach the demand of the comprehensive inspection such as operating the rail-inspection and wheel-inspection at the same time. A monitoring scheme for the railway health based on composite sensing technique has been investigated in this paper. The system discussed in the article is based on the fiber Bragg grating (FBG) sensor array. By collecting and analyzing the data from the sensors which are distributed on rails and bodies, we can evaluate the speed, loads and traffic status of trains.