Planar Photonic Crystal Nanolasers (II): Low-Threshold Quantum Dot Lasers

Tomoyuki YOSHIE  Oleg B. SHCHEKIN  Hao CHEN  Dennis G. DEPPE  Axel SCHERER 

Publication
IEICE TRANSACTIONS on Electronics  Vol.E87-C  No.3  pp.300-307
Publication Date: 2004/03/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Photonic Crystals and Their Device Applications)
Category: INVITED
Keyword: 
photonic crystal,  low-threshold laser,  coupled cavity,  square lattice,  single quantum dot laser,  strong coupling, 

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Summary: 
We have demonstrated low-threshold two-dimensional photonic crystal lasers with self-assembled InAs/GaAs quantum dots. Coupled cavity designs of whispering gallery modes are defined in square lattice photonic crystal slabs. Our lasers showed a small 120 µW input pumping power threshold. Actual absorption power is evaluated to be less than 20 µW. Our lasers show high spontaneous emission coupling (β) factors0.1. The mode volumes are expected to be 0.7-1.2 times cubed wavelength by our modelling. Based on threshold analysis, 80 QDs are the effective number of QDs defined as the number of QDs needed to make PC cavities transparent if they are on maximum optical field points. Using the same analysis we found that single quantum dot lasing is likely to occur both by proper alignment of the single quantum dot relative to geometries of photonic crystals and by using sharp QD emission lines in high-Q localized modes.