A method for instant splicing of an optical fiber to an optical waveguide or bulk material comprises forming a nanometric conductive layer at the interface between the optical fiber and the optical waveguide or bulk material to be spliced, and applying laser radiation to the interface through the fiber optical internally or through the bulk material externally, to produce an arc discharge due to the laser light electric field. The arc discharge melts and diffuses the conductive layer to produce a permanent splice having a low optical loss.