@article { ISI:000259232300019,
	title = {Small-divergence semiconductor lasers by plasmonic collimation},
	journal = {NATURE PHOTONICS},
	volume = {2},
	number = {9},
	year = {2008},
	month = {SEP},
	pages = {564-570},
	publisher = {NATURE PUBLISHING GROUP},
	type = {Article},
	address = {MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND},
	abstract = {Surface plasmons offer the exciting possibility of improving the functionality of optical devices through the subwavelength manipulation of light. We show that surface plasmons can be used to shape the beams of edge- emitting semiconductor lasers and greatly reduce their large intrinsic beam divergence. Using quantum cascade lasers as a model system, we show that by defining a metallic subwavelength slit and a grating on their facet, a small beam divergence in the laser polarization direction can be achieved. Divergence angles as small as 2.4 degrees are obtained, representing a reduction in beam spread by a factor of 25 compared with the original 9.9-mu m-wavelength laser used. Despite having a patterned facet, our collimated lasers do not suffer significant reductions in output power (similar to 100 mW at room temperature). Plasmonic collimation provides a means of efficiently coupling the output of a variety of lasers into optical fibres and waveguides, or to collimate them for applications such as free-space communications, ranging and metrology.},
	issn = {1749-4885},
	doi = {10.1038/nphoton.2008.152},
	author = {Nanfang Yu and Fan, Jonathan and Wang, Qijie and Pfluegl, Christian and Diehl, Laurent and Edamura, Tadataka and Yamanishi, Masamichi and Kan, Hirofumi and Federico Capasso}
}
