Future Trends in Microelectronics: Up the Nano Creek

Wavelength Tuning of Interband Cascade Lasers Based on the Stark Effect

S. Suchalkin, M. Kisin, S. Luryi, G. Belenky

State University of New York at Stony Brook, Stony Brook, NY 11794-2350, U.S.A.

F. Towner, J. D. Bruno

Maxion Technologies, Inc., Hyattsville, MD 20782-2003, U.S.A.

C. Monroy and R. L. Tober

Army Research Laboratory, Adelphi, MD 20873-1197, U.S.A.

1.   Introduction

Tunable mid-IR lasers are in high demand for various military and civilian applications, such as free space communication, remote sensing, and environmental monitoring. The Stark effect, that is the energy level shift in an external electric field, provides an attractive mechanism for semiconductor laser tuning in that it allows an ultrafast and fully electrical control over a broad range of emission wavelengths. This mechanism is especially promising for cascade lasers, both type-I quantum cascade lasers (QCLs) and type-II interband cascade lasers (ICLs), where the spatially indirect lasing transition can be easily tuned with a strong first-order Stark shift. There is one major obstacle, however, on the way to a practical implementation of the Stark-effect tunable device. The laser generation condition (gain equals loss) usually pins the carrier concentration in the laser active region above threshold at a fixed level (the so-called concentration clamping effect). The concentration clamping does not allow any changes of the electric field in optically active layers by pinning the field to its threshold ...