%0 Journal Article %J APPLIED PHYSICS LETTERS %D 2013 %T High-brightness tapered quantum cascade lasers %A Goekden, Burc %A Mansuripur, Tobias S. %A Blanchard, Romain %A Wang, Christine %A Goyal, Anish %A Sanchez-Rubio, Antonio %A Turner, George %A Federico Capasso %X An index-guided tapered quantum cascade laser emitting near 9.5 mu m with sloped sidewalls and no anti-reflection coating is presented, and the performance for devices with taper half-angles of 1 degrees and 2 degrees is investigated. The 1 degrees device delivers up to 2.5 W of peak optical power at room temperature with beam quality-factor M-2 = 2.08, while the two-degree device outputs 3.8 W with M-2 = 2.25 for a maximum brightness of 1.87 MW cm(-2) sr(-1). (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4791557] %B APPLIED PHYSICS LETTERS %I AMER INST PHYSICS %C CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA %V 102 %8 FEB 4 %G eng %N 5 %9 Article %R 10.1063/1.4791557