Susan P Lyman

US Patent:

44392656, Mar 27, 1984

Filed:

Jul 17, 1981

Appl. No.:

6/284472

Inventors:

Rodney C. Alferness - Holmdel NJ
Lawrence L. Buhl - New Monmouth NJ
Janet L. Jackel - Holmdel NJ
Susan P. Lyman - Matawan NJ
Vellayan Ramaswamy - Lincroft NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

C30B 3106

US Classification:

156606

Abstract:

A simple, inexpensive, and reliable technique for substantially preventing the unwanted formation of a surface guiding layer during manufacture of light-guiding structures in LiNbO. sub. 3 and LiTaO. sub. 3 substrates is disclosed. The technique involves addition of an effective amount of a gaseous hydrogen donor to the processing atmosphere during high-temperature processing. A particularly convenient hydrogen donor is water vapor, which can be added to the atmosphere by, for instance, bubbling of the feed gas through a water column. A partial pressure of more than about 9 Torr of H. sub. 2 O has been found effective in the practice of the technique.