Deposition of Silver Nanoparticles on Indium Tin Oxide Substrates by Plasma-Assisted Hot-Filament Evaporation

Nanoparticles of noble metals have unique properties including large surface energies, surface plasmon excitation, quantum confinement effect, and high electron accumulation. Among these nanoparticles, silver (Ag) nanoparticles have strong responses in visible light region due to its high plasmon excitation. These unique properties depend on the size, shape, interparticle separation and surrounded medium of Ag nanoparticles. Indium tin oxide (ITO) is widely used as an electrode for flat panel devices in such as electronic, optoelectronic and sensing applications. Nowadays, Ag nanoparticles were deposited on ITO to improve their optical and electrical properties. Plasma-assisted hot-filament evaporation (PAHFE) technique produced high-density of crystalline Ag nanoparticles with controlling in the size and distribution on ITO surface. In this chapter, we will discuss about the PAHFE technique for the deposition of Ag nanoparticles on ITO and influences of the experimental parameters on the physical and optical properties, and electronic structure of the deposited Ag nanoparticles on ITO

FIrpic thin film as saturable absorber for passively Q-switched and mode-locked erbium-doped fiber laser

In this paper, we demonstrate the generation of passive all-fiber Q-switched and mode locked erbium doped fiber lasers (EDFLs) by using Bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato) iridium(III) (FIrpic) as a saturable absorber (SA). The material was prepared by solvent-casting technique and inserted between two fiber ferrules to form an SA. Then it was placed in an EDFL cavity. A stable Q-switched pulse laser operating at 1560.4 nm was achieved at a threshold pump power of 30 mW. The pulse repetition rate increased from 39.22 to 87.4 kHz and the pulse width decreased from 9.5 to 3.4 µs as the pump power was gradually increased from 30 to 208 mW. Meanwhile, a soliton self-starting mode-locking pulses at a wavelength of 1562.57 nm was achieved by adding an additional 52 m SMF to the EDFL cavity. The mode-locked laser had a repetition rate of 3.43 MHz and a pulse width of 120 ns within the pump power of 35–185 mW. The results suggest that FIrpic SA can be used to produce stable Q-switched and mode-locked fiber lasers at a low pump power. © 2019 Elsevier Inc

Tris-(8-hydroxyquinoline) aluminium thin film as saturable absorber for passively Q-switched erbium-doped fibre laser

A passively Q-switched erbium-doped fibre laser was demonstrated by using tris-(8-hydroxyquinoline)aluminium (Alq3) organic material as a passive saturable absorber (SA). The SA was fabricated by a drop casting technique at room temperature and incorporated into a laser cavity by inserting it between two optical fibre ferrules. The Q-switched fibre laser operates at a centre wavelength of 1559 nm with a full-width half maximum of 1 nm. The generated pulse train is stable and has a pulse width decreased from 6.65 to 1.2 μs and the pulse repetition rate increased from 31.65 to 144.5 kHz as the pump power increased from 20 to 122 mW. The maximum pulse energy obtained is 63.89 nJ. This work indicates that the Alq3 as SA has a great potential to be utilised for pulsed laser generation. To the best of the authors' knowledge, this is the first time an organic material is utilised as a SA device for generating a stable Q-switched laser pulse. © 2019 Institution of Engineering and Technology. All rights reserved