Total internal reflection optical switches employing thermal activation

A switching element for use along an optical path comprising:

• a waveguide substrate having at least two optical waveguide segments on a first surface of said waveguide substrate, including first and second waveguide segments having ends that intersect a gap, said first and second waveguide segments being in fixed relation and generally parallel to said surface;
• a heater substrate having first and second heaters, said heater substrate being joined to said waveguide substrate such that said first heater is aligned with said gap;
• and
• a liquid disposable within said gap, said liquid being responsive to activation of said first and second heaters, said liquid having an index of refraction such that optical transmission from said first waveguide segment to said second waveguide segment is determined by presence of said liquid within said gap;
• wherein said first and second heaters are controllable for generating a gas bubble and for selectively attracting said gas bubble, said first and second heaters being spaced apart and said first heater being positioned to attract said gas bubble to said end of said first waveguide segment.

A switching element for use along an optical path comprising:

• a substrate having a surface;
• a first optical waveguide segment having a first end that is in fixed relation to said substrate and directed generally parallel to said surface;
• a second optical waveguide segment having a second end that is in fixed relation to said substrate and directed generally parallel to said surface, said second end and said first end intersecting a gap;
• a liquid disposable within said gap, said liquid having an index of refraction such that optical transmission from said first optical waveguide segment to said second optical waveguide segment is determined by a presence of said liquid within said gap;
• and
• a jet mechanism aligned relative to said gap to displace said liquid in a direction generally perpendicular to said surface, said jet mechanism including a heater for generating thermal energy.

A switching arrangement for defining a transmitting state and a reflecting state comprising:

• a waveguide substrate having first and second waveguides aligned for optical communication when said transmitting state is defined, said first and second waveguides each having first and second waveguide segments, with each waveguide segment extending to a fluid chamber;
• a heater substrate bonded to said waveguide substrate, said heater substrate having heater means in thermal communication with said fluid chamber for forming one of a gas bubble and a vapor bubble between said waveguide segments of said first and second waveguides in response to activation of said heater means;
• and
• control means for activating and deactivating said heater means to initiate manipulation of fluid within said fluid chamber, said manipulation including an operation of thermal degassing and attraction if said bubble is a gas bubble and including an operation of vaporization and condensation if said bubble is a vapor bubble.

An optical routing matrix comprising:

• a waveguide substrate;
• an array of generally parallel first waveguides extending parallel to said waveguide substrate to define first optical paths;
• an array of generally parallel second waveguides extending parallel to said waveguide substrate to define second optical paths that intersect said first optical paths at fluid chambers;
• and
• a heater substrate joined to said waveguide substrate, said heater substrate having microheaters in thermal communication with said fluid chambers to form bubbles within said fluid chambers, each fluid chamber being operatively associated with one of said microheaters and being configured such that fluidic changes as a result of activation of said operatively associated microheater determine a presence of fluid in said fluid chamber.

A method of fabricating a switching element for an optical path comprising steps of:

• forming a waveguide substrate having first and second intersecting waveguides;
• forming a trench at an intersection of said first and second waveguides a trench for receiving a liquid having an index of refraction such that optical transmission between said first and second waveguides is determined by presence of said liquid at said intersection;
• forming a heater substrate having a heating element;
• aligning said heater substrate with said waveguide substrate such that said heating element is aligned with said intersection;
• and
• bonding said aligned heater and waveguide substrates.