Title :
Carriers density imaging by self-mixing interferometry in a THz quantum cascade laser
Author :
Columbo, L.L. ; Mezzapesa, F.P. ; Dabbicco, M. ; Brambilla, M. ; Scamarcio, G. ; Vitiello, M.S.
Author_Institution :
Dipt. Interateneo di Fis., Univ. degli Studi e Politec. di Bari, Bari, Italy
Abstract :
We propose a THz imaging system based on self-mixing (SM) interferometry in a Quantum Cascade Laser (QCL) to map the distribution of free charges on a semiconductor surface. In our experiment a free electron plasma is photo-generated in a high resistivity n-type silicon wafer using a near infrared (NIR) continuous wave (CW) pump laser. A model based on Drude theory correctly reproduces the experimental results and in prospective promises a quantitative evaluation of free charges densities.
Keywords :
carrier density; elemental semiconductors; light interferometry; microwave photonics; optical pumping; plasma production by laser; quantum cascade lasers; silicon; terahertz wave imaging; Drude theory; QCL; THz imaging system; THz quantum cascade laser; carriers density imaging; free electron plasma; high resistivity n-type silicon wafer; near infrared continuous wave pump laser; self-mixing interferometry; semiconductor surface; Charge carrier density; Imaging; Laser beams; Laser excitation; Quantum cascade lasers; Silicon; Surface emitting lasers; THz imaging; quantum cascade laser; self-mixing interferometry;
Conference_Titel :
SENSORS, 2014 IEEE
Conference_Location :
Valencia
DOI :
10.1109/ICSENS.2014.6985109
