Sensing and Demodulation of Special Long-Period Fiber Gratings Induced by Scanning Laser Pulses
Figure 21
Schematic diagram of the system for the reflective band pass LPFG demodulated by fiber ring laser. : 20 : 80 coupler, LD: laser diode, WDM1 and WDM2: 980/1550 nm wavelength division multiplexer, EDF: erbium-doped fiber, Re-LPFG: reflective band pass filter, and : polarization controller, ISO: isolator, OC: optical circulator, and : 1 : 99 coupler.
