Semiconductor quantum dots fiber amplifier excited by evanescent wave

Abstract

Based on semiconductor quantum dots and a tapered optical fiber, an optical fiber amplifier was proposed and studied in this paper. It was fabricated by coating PbS quantum dots doped sol-gel onto the tapered region of optical fiber. The PbS quantum dots were synthesized by colloidal method. The tapered optical fiber was made by using a standard single mode fiber through heating of CO 2 laser. With a Wavelength Division Multiplexer (WDM), a signal and a pump can be injected into the fiber tapered region and interacts with the quantum dots through the evanescent field so that the signal can be amplified. The optical gain was characterized and more than 10dB gain was obtained at 1310nm with only 1.6cm interacting length at 130mw pump power.