Design of Dynamic Gain Equalizer With H-PDLC Reflection Gratings Doped With Ag Nanoparticles

In this letter, the characteristics of holographic polymer-dispersed liquid crystal reflection gratings doped with Ag nanoparticles (NPs) and their incorporation with dynamic gain equalizers are reported. Experimental results show that the addition of small quantities of Ag NPs causes considerable effects on holographic reflection gratings. Reflection efficiency of gratings improves with the addition of a 0.2% Ag NP solution. Refractive index modulation of doped gratings reached $4.8\,\times \,10^{-3}$ experimentally. Taking advantage of reflective wavelength and electrically controlled refractive index modulation of gratings, cascades for several grating-based dynamic gain equalizers were proposed and testified. These can be incorporated with erbium-doped fiber amplifiers. Simulated results show that the fluctuation range of a typical gain spectrum for an erbium-doped fiber amplifier can be reduced from 3.3 to 0.23 dB.