The switch combines inkjet technology and planar waveguides, and is a hybrid silicon and silica device. The silica section includes solid optical waveguides intersected, at the cross points, by trenches filled with index-matching fluid. When the device is flip-chip bonded, the heaters are located near the cross points of the waveguides. When the optical signal needs to be rerouted, a bubble is created, filling the trench near the waveguide. Waveguides in the switch are interrupted by trenches filled with index-matching fluid.
Unswitched beams pass straight through the trenches and back into the waveguide.
Switched beams bounce into the new waveguide by total internal reflection off a bubble that overfills the trench. Image courtesy of Agilent Technologies. Speed and crosstalk Switching time for the device, including the control software, is 10 ms. Telecom service providers want to be able to change a connection within 50 ms so they don't drop calls. They need to be able to do the hardware part in 10 ms or less.