Enhancing Amplifier Characteristics Using Quantum Dots

Abstract

Wavelength division multiplexing (WDM) is getting popularity because it is using optical fiber technology, which allows thousands of channels with various wavelengths to be transmitted at the same time. Practically, the transmission capacity of WDM systems strongly depends on the gain bandwidth of a fiber amplifier. Optical fiber amplifiers that are doped with rare earth ions are the most worked upon fiber amplifiers over few decades. In recent years, quantum dots are parts of semiconductor nanocrystals being studied extensively, because they have unique optical properties and electronic properties compared to the bulk semiconductors [1]. This is because they have low band gap due to their tiny particle size. Due to this, QDs can provide near-infrared emission covering the important wavelengths. Researchers have doped the optical fiber core by quantum dots (QDs) to integrate the emission characteristics of quantum dots with the propagation characteristics of optical fiber [2]. The promising feature for all-wave optical amplifiers is that the PbS nanocrystals could provide emission for silica fibers over the whole transmission window (1200–1700). Simulation results show that it is possible to design an optical amplifier with low noise figure, moderate optical signal-to-noise ratio with minimum gain of 10 dB.