Patent ID: 6798939
Filing Date: 2004-09-28
Classification: G02B

Abstract:
In a method of fabricating an optical switch having a microheater in heat-transfer relationship with a liquid-containing trench that is intersected by an optical waveguide, wherein said optical switch has a transmissive state in which liquid is at an interface of said trench with said optical waveguide and said optical switch has a reflective state in which a bubble is at said interface, said method comprising the steps of:using first and second substrates in forming said microheater and said trench and said optical waveguide, including intentionally modifying surface features of at least one of said first and second substrates to control escape of said bubble from said trench when said optical switch is in said reflective state, wherein intentionally modifying surface features includes forming raised barriers on at least one of said first and second substrates; and connecting said first substrate to said second substrate such that spacing exists between said first and second substrates adjacent to said trench, including designing said first and second substrates such that said intentionally modified surface features control the position of said bubble relative to said trench and said spacing.