Effect of Ge Nanoparticles in the Core of Photonic Crystal Fiber on Supercontinuum Generation

Abstract

The effect of Ge nanoparticle (Ge NP) incorporation in the germanosilicate glass core of the photonic crystal fiber (PCF) on supercontinuum generation (SCG) was investigated. The Ge NP-doped germanosilicate glass core PCF was fabricated by using the modified chemical vapor deposition (MCVD) and the stack-and-draw processes. The average diameter of Ge NPs embedded in the core of the PCF was 4.2nm. The absorption peaks at 480nm and 515nm and the band from 600 to 800nm were attributed to the Ge NPs in the core of the PCF. SCG of the 490nm bandwidth (598nm1088nm) with a conversion efficiency of 31% was obtained by pumping at 800nm with the Ti:sapphire femtosecond laser of 160mW with 35fs pulse at 1kHz repetition rate, resulting from the enhanced optical nonlinearity from Ge NPs as well as the PCF structure of the fiber.