Photonic crystal-based MOEMS devices

In this paper, a new class of microoptoelectromechanical system (MOEMS) devices combining photonic crystals (PCs) formed in in-plane waveguiding membranes (in-plane 1-D or 2-D large contrast modulation of the optical index) and a multilayer stack (1-D "vertical" modulation of the optical index) according to the so-called 2.5-D micronanophotonics approach is reported. The operation of the devices is based on the resonant coupling between radiated optical modes and slow Bloch modes waveguided in the particular membranes of the stack, which are laterally patterned to form a PC. Use of high-index contrast PC gratings result in enhanced lateral compactness of the devices. The MOEMS functionality is achieved via micromechanical subwavelength vertical displacement of some of the suspended membranes. Recent demonstrations of devices (including tunable filters and surface-emitting microsources) operating along these principles are presented.