Total reflection optical waveguide switching through dielectric chip motion

Devices Based on Co-Integrated MEMS Actuators and Optical Waveguide: A Review

The convergence of Micro Electro Mechanical Systems (MEMS) and optics was, at the end of the last century, a fertile ground for a new breed of technological and scientific achievements. The weightlessness of light has been identified very early as a key advantage for micro-actuator application, giving rise to optical free-space MEMS devices. In parallel to these developments, the past 20 years saw the emergence of a less pursued approach relying on guided optical wave, where, pushed by the similarities in fabrication process, researchers explored the possibilities offered by merging integrated optics and MEMS technology. The interest of using guided waves is well known (absence of diffraction, tight light confinement, small size, compatibility with fiber optics) but it was less clear how they could be harnessed with MEMS technology. Actually, it is possible to use MEMS actuators for modifying waveguide properties (length, direction, index of refraction) or for coupling light between waveguide, enabling many new devices for optical telecommunication, astronomy or sensing. With the recent expansion to nanophotonics and optomechanics, it seems that this field still holds a lot of promises.

Optical waveguide 2 x 2 matrix switch using dielectric chip motion

Input and output light angles in a total internal reflection optical waveguide switch, in which a guided light beam is switched by dielectric chip contact with a low-index channel built in a waveguide film, are studied to construct a matrix switch. Output angle depends on channel width, chip contact width, chip position, and input angle. In a single switch experiment, the output angle is larger than the total reflection critical angle for the channel due to narrow chip contact width. By utilizing this property, a nonblocking 2 x 2 matrix switch, driven by PZT bimorphs, is fabricated. Insertion losses of 2.9-6.0 dB, cross talk values of 10.8-28.1 dB, and switching time of 6 msec are obtained for the TE(0) mode at 0.633-microm wavelength.