Gold-nanorod-facilitated nonlinear optical microscopy under radially polarised beam illumination

Reports on the use of radially polarised beam in gold-nanorod-facilitated nonlinear microscopy and therapy. It has been found that the use of radially polarised beam can greatly reduce the energy fluence threshold for treating cancer cells labelled with gold nanorods. The slight distortion in the polarisation properties of the radially polarised beam after propagating through double-clad photonic crystal fibres makes it promising in the application of fibre-optic based endoscopic system.