Articles you may be interested in290 fs switching time of Fe-doped quantum well saturable absorbers in a microcavity in 1.55 μ m range Appl. Phys. Lett. 85, 5926 (2004); 10.1063/1.1804239 Nonlinear absorption temporal dynamics of Fe-doped GaInAs/InP multiple quantum wells J. Appl. Phys. 94, 2355 (2003); 10.1063/1.1591077 High-speed 1.55 μm Fe-doped multiple-quantum-well saturable absorber on InP Appl. Phys. Lett. 78, 4065 (2001); 10.1063/1.1381410 Time-frequency spectroscopy of an InGaAs/InP quantum-well exciton Bragg reflector Appl. Phys. Lett. 74, 2569 (1999); 10.1063/1.123900 Carrier lifetime and exciton saturation in a strain-balanced InGaAs/InAsP multiple quantum well

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Articles you may be interested in290 fs switching time of Fe-doped quantum well saturable absorbers in a microcavity in 1.55 μ m range Appl. Phys. Lett. 85, 5926 (2004); 10.1063/1.1804239 Ultrashort, nonlinear, optical time response of Fe-doped InGaAs/InP multiple quantum wells in 1.55-μm range Appl. Phys. Lett. 82, 1670 (2003); 10.1063/1.1557333 High-speed 1.55 μm Fe-doped multiple-quantum-well saturable absorber on InP Appl. Phys. Lett. 78, 4065 (2001); 10.1063/1.1381410 Time-frequency spectroscopy of an InGaAs/InP quantum-well exciton Bragg reflector Appl. Phys. Lett. 74, 2569 (1999); 10.1063/1.123900Carrier lifetime and exciton saturation in a strain-balanced InGaAs/InAsP multiple quantum well GaInAs/InP multiple quantum wells ͑MQWs͒ are used as saturable absorbers for all-optical signal regeneration at a 1.55-m wavelength. These MQWs are doped during their growth by molecular-beam epitaxy with Fe to improve their temporal response. The present work develops a theoretical description of the carrier recombination dynamics in these MQWs. Temporal evolution of the populations of excitons, holes, electrons, and iron traps is determined by coupled evolution equations. The model describes the optical temporal nonlinearity of the saturable absorbers near the excitonic peak transition. Furthermore, pump-probe experiments have been performed to measure the recovery time of these structures having different Fe doping concentrations. A good agreement between the experimental measurements and the model predictions of the optical temporal behaviors of the saturable absorbers is obtained. The control of the recovery time ͑nanoseconds to picoseconds͒ with the Fe traps in a large concentration range (10 15 to 10 19 cm Ϫ3 ) is particularly well highlighted by this model. The Fe doping concentration prescribed to reach a targeted fast recovery time is predicted with good accuracy by the model, which leads us to propose an attractive way to design ultra-high-speed, all-optical signal regenerators based on saturable absorbers.

Thin films and ridge waveguides based on large-diameter semiconducting single-wall carbon nanotubes (s-SWCNTs) dispersed in a polyfluorene derivative are fabricated and optically characterized. Ridge waveguides are designed with appropriate dimensions for single-mode propagation at 1550 nm. Using multimode ridge waveguides, guided s-SWCNT photoluminescence is demonstrated for the first time in the near-infrared telecommunications window.

In this paper, we demonstrate that the alignment density of individualized single-walled carbon nanotubes (SWCNTs) can be greatly improved by heating-enhanced dielectrophoresis (HE-DEP) process. The observations by scanning electron microscope (SEM) suggest ultrahigh alignment density and good alignment quality of SWCNTs. The intuitive alignment density of individualized SWCNTs is much higher than the currently reported best results. The reason of this HE-DEP process is explained by simulation work and ascribed to the heating-enhanced convection process, and the “convection force” induced by the heating effect is assessed in a novel way.