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:
Feb. 27, 1979
Filed:
Aug. 05, 1977
Roger L Aagard, Richfield, MN (US);
Robert P Ulmer, Minneapolis, MN (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
In thin film optical systems including thin film optical waveguides, of such materials as Nb.sub.2 O.sub.5, it is desirable to fabricate thin film lenses. One of the types of lenses which can be made is the step-in-thickness type. This type of thin-film lens can be fabricated by plasma etching through a photoresist mask in such materials as Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5. Plasma etching yields an etch wall with smooth steep sides which is important for good quality thin-film lenses; however, the etch rate is too variable for reproducible etch depth based upon etch time, and the bottom of the etch is very rough, causing excessive scattering loss. It has been found that a sandwich-like structure of Nb.sub.2 O.sub.5, TiO.sub.2 and Nb.sub.2 O.sub.5 provides an improved arrangement in that a good control of the etch depth and a smooth flat bottom in the etch areas have been achieved by introducing the layer of TiO.sub.2 as an etch stop.