Intensity-dependent frequency shift in surface plasmon amplification by stimulated emission of radiation

摘要

The operation of a surface plasmon amplification by stimulated emission of radiation- (spaser)-based nanolasernis theoretically investigated.We find that the lasing frequency undergoes a shift as the lasing intensity increases, anresult that agrees with recent experiments.We show that the mechanism of the intensity-dependent shift involvesna spatial deformation of the lasing mode, which is induced by the spatial hole burning in the surrounding gainnmedia.We develop a general analytical scheme to account for the mode deformation. Our numerical calculationsndemonstrate good correspondence of the lasing frequency shift with the experimental data for the simplestn(spherical) geometry of the spaser.