Author Affiliations

Alex Soibel,^*,1 Milton L. Peabody,¹ A. Michael Sergent,¹ Deborah L. Sivco,¹ Alfred Y. Cho,¹ Federico Capasso,² Claire Gmachl,³ Roberto Paiella,⁴ Harold Y. Hwang,⁵ H. C. Liu,⁶ Christian Jirauschek,⁷ and Franz X. Kärtner⁷

¹Bell Laboratories, Lucent Technologies, 600 Mountain Ave, Murray Hill, NJ, 07974, USA.

²Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.

³Department of Electrical Engineering, Princeton University, Princeton, NJ, 08544, USA.

⁴Department of Electrical and Computer Engineering, Boston University, 8 St. Mary’s Street, Boston, MA, 02215, USA.

⁵Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan.

⁶Institute of Microstructural Science, National Research Council, Ottawa, Ontario, K1A R6 Canada.

⁷Department of Electrical Engineering, MIT, Cambridge, MA, 02139, USA.

^*Corresponding author: hsasha@lucent.com