The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 22, 2005
Filed:
Oct. 10, 2002
Dorothea W. Wiesmann, Zurich, CH;
Folkert Horst, Zurich, CH;
Bert Offrein, Langnau am Albis, CH;
Gian-luca Bona, Hedingen, CH;
Dorothea W. Wiesmann, Zurich, CH;
Folkert Horst, Zurich, CH;
Bert Offrein, Langnau am Albis, CH;
Gian-Luca Bona, Hedingen, CH;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of inducing phase changes in a FIR filter is provided. The FIR filter consists of a concatenation of tunable couplers and tunable delay lines made of planar waveguides fabricated in SiON technology, forming a plurality of interferometers, at least one of which carries a heater on at least one of its waveguide arms. The method includes the step of exposing at least one of the arms of the interferometers to an irradiation at UV or a smaller wavelength, thereby inducing a change in the refractive index of the waveguide arms which induces the phase difference change. The method provides a procedure that will lead to temperature-stable changes of the refractive index of the waveguides. The resulting device is temperature-stable such that it can be afterwards be heated with chromium heaters to dynamically tune its spectral response without destroying the UV-induced changes.