arXiv:physics/0604125 · Applied Physics Letters
Balanced homodyne detection of second-harmonic generation from isolated subwavelength emitters
Loc Le Xuan, Sophie Brasselet, François Treussart, Jean-François Roch, François Marquier, Dominique Chauvat, Sandrine Perruchas, Cédric Tard, Thierry Gacoin
Abstract
The authors demonstrate the association of two-photon nonlinear microscopy with balanced homodyne detection for investigating second-harmonic radiation properties at nanoscale dimensions. Variation of the relative phase between second-harmonic and fundamental beams is retrieved, as a function of the absolute orientation of the nonlinear emitters. Sensitivity down to a few photons per second in the spatiotemporal mode of the local oscillator is obtained. This value is high enough to efficiently detect the coherent second-harmonic emission from a single KTiOPO4 crystal of subwavelength size.