Carrier dynamics investigation in quantum cascade lasers using Mid-IR ultrafast pulses

Sheng Liu; Elaine Lalanne; Peter Q. Liu; Xiaojun Wang; Anthony Johnson; Claire Gmachl

doi:10.1117/12.875787

21 February 2011 Carrier dynamics investigation in quantum cascade lasers using Mid-IR ultrafast pulses

Sheng Liu, Elaine Lalanne, Peter Q. Liu, Xiaojun Wang, Anthony Johnson, Claire Gmachl

Proceedings Volume 7937, Ultrafast Phenomena in Semiconductors and Nanostructure Materials XV; 79370Q (2011) https://doi.org/10.1117/12.875787
Event: SPIE OPTO, 2011, San Francisco, California, United States

Abstract

Quantum cascade lasers (QCLs) are unipolar devices composed of repeated stack of semiconductor multiple quantum well heterostructures utilizing intersubband transitions and resonant tunneling. In this paper, 120 fs Mid-IR pulses are used to investigate the nature of carrier transport through the quantum wells and barriers of a pulse biased, room temperature operating ultrastrong coupling design QCL. Despite the low average power of Mid-IR pulses, we managed to efficiently couple these pulses into the QCL waveguide so as to observe distinct phenomena by varying the pump and probe's power. Biased just below the threshold, we observed a strong gain depletion dip at t=0 which is mainly caused by the depletion of electrons from the upper lasing state mainly by stimulated emission. Ultrafast gain recovery within the first 200 fs was observed. This is mainly attributed to phonon scattering and electrons resonantly tunneling through a much thinner injector barrier, which overcomes the interface-roughness-induced detuning of resonant tunneling. Electron transport through the injector region contributes to a slower gain recovery lifetime of 2-3 ps.

Citation Download Citation

Sheng Liu, Elaine Lalanne, Peter Q. Liu, Xiaojun Wang, Anthony Johnson, and Claire Gmachl "Carrier dynamics investigation in quantum cascade lasers using Mid-IR ultrafast pulses", Proc. SPIE 7937, Ultrafast Phenomena in Semiconductors and Nanostructure Materials XV, 79370Q (21 February 2011); https://doi.org/10.1117/12.875787

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available