Search results for "Laser theory"
showing 5 items of 35 documents
Selective modification of the band gaps of GaInNas/GaAs structures by quantum well intermixing techniques
2003
We report the unambiguous demonstration of controlled quantum well intermixing (QWI) in the technologically important GaInNAs/ GaAs 1.3 mum material system. QWI is a key technique to selectively modify the band gap of quantum wells, which has found broad application in semiconductor lasers and photonic integrated circuits (PICs). Extending such technology to GaInNAs/GaAs structures is highly desirable due to the technologically advantageous properties of this material system. Here, we investigate well-characterized GaInNAs quantum well material which has been annealed "to saturation" before QWI processing to allow unambiguous interpretation of results. After RTA at 700 degreesC for similar …
Three-dimensional dynamic light scattering
1999
Abstract We describe the employment of a novel light-scattering scheme for the decorrelation of multiple scattering in strongly turbid samples. The three-dimensional scheme, which has been proposed already theoretically, shows certain advantages compared with the two-colour apparatus, which is commercially available. We describe our set-up in detail; features are the use of modern semiconductor laser diodes and contemporary single-mode fibre receivers. We show experimentally that the optimal signal-to-noise ratio (or intercept) β opt = 0.20, which is obtainable with our set-up, can be quantitatively calculated from the measured uncertainties in the alignment. In particular, we give a detail…
Universal soliton pattern formations in passively mode-locked fiber lasers
2011
International audience; We investigate multiple-soliton pattern formations in a figure-of-eight passively mode-locked fiber laser. Operation in the anomalous dispersion regime with a double-clad fiber amplifier allows generation of up to several hundreds of solitons per round trip. We report the observation of remarkable soliton distributions: soliton gas, soliton liquid, soliton polycrystal, and soliton crystal, thus indicating the universality of such complexes.
Economical device for measuring thickness of a thin polymer film
1994
An inexpensive device (about $2K) for thickness measurements of thin (<1 μm) polymer films has been constructed. The homogeneous film is placed on a bulk substrate and three semiconductor lasers of different wavelengths are used to measure the reflectances at normal incidence. The thickness can be deduced with typically 4–8 nm uncertainty.
Rayleigh-instability-driven dewetting of thin Au and Ag films on indium-tin-oxide surface under nanosecond laser irradiations
2013
Investigations have been carried out on laser-beam-induced nanoparticle (NP) formation in thin (5 nm) Au and Ag films on indium-tin-oxide substrate. After the irradiation the films were observed to break-up into NPs through a dewetting mechanism. This mechanism was investigated as a Rayleigh-instability- driven process. In fact, for each used laser fluence, the resulting Au and Ag NPs' mean size and surface-to-surface mean distance were quantified and correlated between them in the framework of the Rayleigh-instability theory showing an excellent agreement. © The Institution of Engineering and Technology 2013.