Inducing forced and auto oscillations in one-dimensional photonic crystals with light

Abstract

We induced forced and auto oscillations in one-dimensional photonic crystals with localized defects when light impinges transversally to the defect layer. The photonic structure consists of a microcavity like structure formed of two onedimensional photonic crystals made of free-standing porous silicon, separated by variable air gap and the working wavelength is 633 nm. The force generation is made evident by driving a laser light by means of a chopper; the light hits the photonic structure and induces a vibration and the vibration is characterized by using a very sensitive vibrometer. Moreover we measured peak displacements and velocities ranging from 2 up to 35 microns and 0.4 up to 2.1 mm/s with a power of 13 mW. Recent evidence showed that giant resonant light forces could induce average velocity values of 0.45 mm/s in microspheres embedded in water with 43 mW light power.