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US 6,185,355 B2Granted
Process for making high yield, DC stable proton exchanged waveguide for active integrated optic devices
OwnerHenry H. Hunginventor
Life of this patent
Estimating the term…
Abstract
A process for greatly improving the DC drift problem associated with LiNbO3 and LiTaO3 substrates. The process immerses the substrates in a heat bath comprised of a strong acid and then subjects the substrates to cyclical annealing.
Claims17
An active integrated optic (IO) device, comprising
- (a) a crystalline material substrate having at least one surface;
- (b) an integrated optic circuit, including an optical waveguide and at least one electrode disposed in juxtaposition on said surface to provide at least one integrated optic region thereon;
- as characterized by:
- (c) said optical waveguide being formed in said surface by a two step proton exchange process comprising the steps of:
- (i) immersing said substrate for a period of time in a heated bath including at least 70% by weight of a strong acid, and
- (ii) cyclically differentially annealing said substrate by heating and cooling said substrate through at least
- a first annealing cycle comprising
- first heating said substrate through an up-ramp to a first elevated temperature above room temperature, and
- cooling said substrate from said elevated temperature through a down-ramp to a first low temperature which is at least seventy-five degrees C. lower than said elevated temperature, and
- a second annealing cycle subsequent to said first annealing cycle and comprising
- first heating said substrate through an up-ramp to a second elevated temperature above room temperature and above said low temperature, and
- cooling said substrate through a down-ramp to a second low temperature which is at least seventy-five degrees C. lower than said second elevated temperature.
9 more elements
A method of fabricating a proton exchanged integrated optic device, comprising the steps of
- (a) preparing a crystalline material substrate with at least one surface;
- (b) forming at least one channel in said surface to produce a selected integrated optic device waveguide;
- (c) immersing said substrate in a heated bath of strong acid;
- and,
- (d) cyclically differentially annealing said substrate by heating and cooling said substrate through at least
- a first annealing cycle comprising
- first heating said substrate through an up-ramp to a first elevated temperature, and
- cooling said substrate from said elevated temperature through a down-ramp to a first low temperature which is at least seventy-five degrees C. lower than said elevated temperature, and
- a second annealing cycle subsequent to said first annealing cycle and comprising
- first heating said substrate through an up-ramp to a second elevated temperature above room temperature and above said low temperature, and
- cooling said substrate through a down-ramp to a second low temperature which is at least seventy-five degrees C. lower than said second elevated temperature.
8 more elements
A method of fabricating a proton exchanged integrated optic device, comprising the steps of
- (a) preparing a crystalline material substrate with at least one surface;
- (b) forming at least one channel in said surface to produce a selected integrated optic device waveguide;
- (c) immersing said substrate in a heated bath of strong acid;
- and,
- (d) cyclically differentially annealing said substrate by heating and cooling said substrate through at least
- a first annealing cycle comprising
- first heating said substrate through an up-ramp to a first elevated temperature, and
- cooling said substrate from said elevated temperature through a down-ramp to a first low temperature which is at least seventy-five degrees C. lower than said elevated temperature,
- a second annealing cycle subsequent to said first annealing cycle and comprising
- first heating said substrate through an up-ramp to a second elevated temperature above said low temperature, and
- cooling said substrate through a down-ramp to a second low temperature which is at least seventy-five degrees C. lower than said second elevated temperature, and
- a third annealing cycle subsequent to said second annealing cycle and comprising
- first heating said substrate through an up-ramp to a third elevated temperature above said second low temperature, and
- cooling said substrate through a down-ramp to a third low temperature which is at least seventy-five degrees C. lower than said third elevated temperature.
11 more elements
Dependencies are inferred from the claim text.