Université de Neuchâtel

Analysis and improvement of the spectral properties in mid-infrared semiconductor quantum cascade lasers

Tombez, Lionel ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2014.

Les lasers à cascade quantique (QCL) sont des lasers à semiconducteur basés sur des transitions inter-sous-bandes. Au contraire des diodes lasers traditionnelles, la longueur d'onde d'émission de ce type de laser n'est pas définie par la bande interdite (bandgap) du matériau semiconducteur, mais par l'écart d'énergie entre les niveaux discrets de plusieurs puits quantiques, ce qui permet...

Université de Neuchâtel

Bound-to-continuum and two-phonon resonance, quantum-cascade lasers for high duty cycle, high-temperature operation

Faist, Jérôme ; Hofstetter, Daniel ; Beck, Mattias ; Aellen, Thierry ; Rochat, Michel ; Blaser, Stéphane

In: Journal of Quantum Electronics (IEEE), 2002, vol. 38, no. 6, p. 533-546

Recent advances in quantum-cascade (QC) laser active-region design are reviewed. Based on a rate equation model of the active region, we show why new gain regions. based on a two-phonon resonance or a bound-to-continuum transition exhibit significantly better performance than the traditional design based on a three-quantum-well active region. Threshold current densities as low as 3...

Université de Neuchâtel

Distributed-feedback quantum cascade lasers emitting in the 9-μm band with InP top cladding layers

Hofstetter, Daniel ; Beck, Mattias ; Aellen, Thierry ; Faist, Jérôme ; Oesterle, Ursula ; Ilegems, Marc ; Gini Emilio ; Melchior, Hans

In: Photonics Technology Letters (IEEE), 2002, vol. 14, no. 1, p. 18-20

Two different high performance quantum cascade distributed-feedback lasers with four quantum-well-based active regions and InP top cladding layers are presented. The first device, which emitted at 9.5 μm, was mounted junction down in order to get high average powers of up to 71 mW at -30°C and 30 mW at room temperature. The other device, which lased at 9.1 μm, was optimized for...