Pitch-variable transmission-type bulk gratings driven by shape memory alloy actuator

This paper describes a novel pitch-variable transmission-type bulk grating fabricated by silicon micromachining technology driven by a shape memory alloy (SMA) actuator. The grating is specially designed to change the pitch easily with a small force and assured moderate stress by finite element method. Using deep reactive ion etching (deep-RIE) technology, the grating has a high aspect ratio more than 10. In the diffraction experiment, more than 10% extension ratio has been obtained. The SMA actuator has been installed to the grating. Due to the two-way shape memory effect, the translation mechanism is simple and is easily controlled.