Am Montag (19.12.22) um 12.00 Uhr c.t. findet der nächste Termin unseres Physikalischen Kolloquiums statt.
Referent ist Dr. Nahan Jukam (RUB) mit seiner Antrittsvorlesung zum Thema: „Investigation of Quantum Cascade Lasers Using Time Domain Spectroscopy „.
Due to their small size and potential for mass fabrication, quantum cascade lasers are promising sources of terahertz (THz) radiation. In contrast to interband laser diodes, the laser transition in quantum cascade lasers takes place between intersubband levels. By careful control of the lengths and composition of quantum wells and barriers during molecular beam epitaxy growth, the injection rates into intersubband levels and intersubband lifetimes can be designed to achieve population inversion.
In this talk THz time-domain spectroscopy is used to measure the stimulated emission resulting from the injection of THz probe pulses into quantum cascade lasers. This allows the alignment of the intersubband levels to be in investigated both above and below threshold and gives unique insights into gain mechanisms. By operating the quantum cascade lasers in a transient regime, the gain above threshold is enhanced which results in large amplification of the THz probe pulses. Injecting a second THz probe pulse into the quantum cascade laser enables two-dimensional spectroscopy to be per-formed and the gain recovery and spatial hole burning response of the quantum cascade lasers to be investigated.
Abstract Vortrag Dr. Nathan Jukam
Die Einführung erfolgt durch Prof. Dr. Ilya Eremin.
Die Fakultät lädt alle Interessierten herzlich ein. Die Veranstaltung findet im Hörsaal HNC 10 und hybrid via Zoom statt. Vor dem Kolloquium bieten wir Ihnen Kaffee und Kekse an.
Über diesen Link gelangen Sie zur Zoom-Veranstaltung (Meeting–ID: 632 5520 9938, Passwort: 526977). Alle Termine des Physikalischen Kolloquiums finden Sie hier.