Patent ID: 7031564

Claim:
A switching element comprising: a bubble chamber that holds fluid, the bubble chamber including: a trench within a planar light circuit, and a trench within an integrated circuit attached to the planar light circuit the trench within the integrated circuit having a bottom surface and at least one wall extending in a direction substantially perpendicular to the bottom surface; a heater under the trench within the integrated circuit; and, a heat conductor attached to the integrated circuit, the heat conductor being placed so as to conduct sufficient heat along the at least one wall so that for a predetermined operating range of the heater, fluid adjacent to the at least one wall is kept above an evaporation point for the fluid, the heat conductor being more heat conductive than the fluid within the bubble chamber, wherein the heat conductor extends in a direction away from the heater so as to conduct heat to fluid at locations in the trench not adjacent to the heater.