Strain-tuning of periodic optical devices: tunable gratings and photonic crystals

We demonstrate strain-tuning of periodic optical devices-diffractive gratings and photonic crystals-on a deformable membrane piezoelectrically actuated with sub-nanometer resolution. In the tunable gratings implementation, period changes up to 8.3 nm (0.21% membrane strain) and diffracted order angular changes up to 486 /spl mu/radians at 10 V are measured, in agreement with the theoretical model. For the strain-tunable photonic crystal microcavity, first-order perturbation theory suggests a 4.2 nm wavelength shift in resonance at C-band optical signals. The fabricated microcavity, with 130 nm minimum feature size, shows resonance at 1555.4 nm and Q of 159.