Patent ID: 7872212
Filing Date: 2011-01-18
Classification: B41J,H01L,Y10T

Abstract:
1. A method for making an optical switch comprising a planar light circuit (PLC), an integrated circuit (IC) and a mesa structure, the method comprising: forming a passivation layer atop the IC; forming the mesa structure atop the passivation layer such that the mesa structure is separated from the IC by the passivation layer and operably connected to metal leads corresponding thereto; forming a waveguide and a trench in an underside of the PLC, the trench being configured to intersect the waveguide at a cross-point disposed above the mesa structure, and forming, for positioning between the mesa structure and the PLC, at least top and bottom resistive layers, the top and bottom resistive layers being separated by an insulating layer disposed therebetween, a first portion of the bottom resistive layer not covered by the metal leads having a surface area larger than a second portion of the top resistive layer not covered by the metal leads, the top and bottom resistive layers being configured to heat the liquid in the trench and thereby effect a change in an index of refraction of the liquid in response to electrical current passing through the top and bottom resistive layers; wherein at least portions of the mesa structure project upwardly above the passivation layer and the top surface of the IC, and at least a portion of the bottom resistive layer is conformably disposed above the upwardly projecting portion of the mesa structure and thereby placed within close proximity to the liquid in the trench to effect efficient heating of the liquid.