Carrier heating in InGaAsP laser amplifiers due to two-photon absorption

Abstract

The carrier dynamics in an InGaAsP quantum-well laser amplifier excited by an ultrashort optical pulse is investigated experimentally as well as theoretically. For operation in the absorption region, a transition from pump induced cooling to pump induced heating of the carriers is observed for increasing pump pulse energy and is attributed to the generation of hot carriers through two-photon absorption. The results further support the interpretation of the carrier dynamics in the perturbative regime.

Nonlinear Photonic Signal Processing Subsystems and Applications

“…TPA is a process where two photons are absorbed in the generation of a single electron-hole carrier pair. It becomes dominant when the input power of the signal is high (Mork & Mark, 1994). Finally, interband carrier recovery takes place.…”

All-Optical Signal Processing with Semiconductor Optical Amplifiers and Tunable Filters

“…Based on theoretical models in literatures (Mork & Mark 1995;Mork, et al, 1994;Mork & Mark 1992;Agrawal & Olsson 1989;Mork & Mecozzi 1996), we can derive theoretical model for SOAs in which ultrafast nonlinear effects are taken into account. Firstly, the propagation equation for the input signal in the SOA can be derived as the following equation: …”

“…In order to calculate the gain coefficient, the local carrier densities should be calculated out firstly. The local carrier densities satisfy the following two equations (Mork, et al, 1994): These relaxation processes are driven by the electron-electron and hole-hole interaction with time constant of τ 1c , τ 1v . The second terms describe carrier consumption due to stimulated emission, and the last terms corresponding to carrier consumption due to two photon absorption.…”

Semiconductor Optical Amplifiers and their Application for All Optical Wavelength Conversion

“…The SOA model includes XGM and XPM effects required to model the wavelength conversion process as well as TwoPhoton Absorption (TPA) and Free-Carrier Absorption (FCA) responsible for the CarrierHeating (CH) and Spectral-Hole Burning (SHB) effects. The equations used for generating the simulation results are detailed in (Mark & Mork, 1992;Mork & Mark, 1994), and are described shortly below: S ) over the cross section of the waveguide (σ i ) and Γ 2 is the corresponding confinement factor for the quantum well region. We have Γ 2 /Γ > 1 due to the tighter confinement of the square of the intensity profile, as well as the higher value for the TPA coefficient in the lower band-gap well region as compared to the separate confinement and cladding regions (Sheik-Bahae et al, 1991).…”

“…In order to fulfill both of the above requirements a special flat top, broad filter with sharp roll off is required (Leuthold et al, 2004). In order to gain a better understanding of the requirements from this sort of filtering technique and its applicability for fast WC we used an SOA band model valid for time responses in the pico-second and sub-picosecond regime (Mork & Mecozzi, 1996;Nielsen et al, 2006;Mark & Mork, 1992;Mork & Mark, 1994). The SOA model includes XGM and XPM effects required to model the wavelength conversion process as well as TwoPhoton Absorption (TPA) and Free-Carrier Absorption (FCA) responsible for the CarrierHeating (CH) and Spectral-Hole Burning (SHB) effects.…”