Luminescent materials based on semiconductor compound templates for random laser applications

Abstract

A survey of methods for the preparation of luminescent nanocomposite materials with the focus on random laser media on the basis of porous semiconductor and dielectric templates is presented. Media with controlled light scattering properties are prepared by electrochemical dissolution of semiconductor substrates, or by electrochemical oxidation of metallic foils. For the introduction of optical gain properties to highly scattering medium prepared by electrochemical technologies, methods for doping porous semiconductor GaP, GaAs and InP as well as dielectric Al2O3 and TiO2 templates with rare earth elements (Eu, Er) and transition metals (Cr, Ti) were developed. The possibility of producing a medium with optical gain properties is demonstrated also by making use of excitonic effects such as exciton‐exciton scattering and stimulated emission of electron‐hole plasma. This approach is suitable for composite materials containing ZnO and ZnSe ingredients. A comparative analysis of the produced structures from the point of view of light emission efficiency, threshold for the onset of laser action, and other characteristics is presented. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Design of titania nanotube structures by focused laser beam direct writing

“…The absorption in our nanotubular structures is also enhanced by light trapping effects due to multiple scattering, since the diameter of nanotubes is of the order of the laser beam wavelength in the material. The photon transport mean-free path deduced from enhanced backscattering measurements in our tubular structures is around 0.6 lm, 17 and such a photonic strength is inherent to light trapping effects. It is obvious that additional investigations are necessary to elucidate the mechanism of optical absorption.…”

Porous semiconductor compounds

“…Porous GaP [150,152,[175][176][177][178] and GaAs [151,152,178] templates have been widely used for the preparation of nanocomposite materials via impregnation processes with rare earth containing solutions followed by thermal treatment to optically activate the rare earth ions. Preparation of various nanocomposite phosphors with the composition and structure controlled by technological conditions has been demonstrated, and efficient optical activation of Er 3+ , Eu 3+ , and Tb 3+ ions was observed as a result of PL and CL investigation.…”

“…The random lasing behavior based on microporous surface of Cr 2+ :ZnSe crystal was found to occur for a wide pump wavelengths ranging from 1500 nm to 1950 nm, which is in accordance with the optical absorption characteristics of Cr 2+ :ZnSe crystal. A series of composite materials prepared on the basis of porous semiconductor GaP, GaAs, and Al 2 O 3 templates doped with rare earth elements and transition metals have been analyzed from the point of view of random lasing action [178]. As described in section 3, a series of composite materials containing Ga 2 O 3 , GaPO 4 , ErPO 4 , EuPO 4 , ErAsO 4 and EuAsO 4 nanophases are formed depending on the technological conditions applied.…”

Recent progress and prospects of random lasers using advanced materials

“…Therefore, it renders RLs as an attractive platform for many applications such as cancer diagnostic 10,11 , Photonic barcodes 12 , a random spectrometer on a chip 13 , speckle-free bio-imaging 14 , speckle-free pulsed imaging technique 15 , sensing 16,17 , optical batteries 18 and optomicrofluidics 19,20,21 . The first type of RLs were dye-based colloidal systems 4,22 and then on many other systems like photonic crystals [23][24] , semiconductors 25,26,27 , quantum dots (QDs) 28,29 , polymeric matrices [30][31] , biological tissues 32 , rare-earth-doped nanopowders 33 , cold atoms 34 , etc. were introduced in the field.…”

“…The first type of RLs were dye-based colloidal systems 4,22 and then on many other systems like photonic crystals, 23,24 semiconductors, 25–27 quantum dots (QDs), 28,29 polymeric matrices, 30,31 biological tissues, 32 rare-earth-doped nanopowders, 33 cold atoms, 34 etc. were introduced in the field.…”