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. 03, 1998
Filed:
Jul. 30, 1996
James Francis Ryley, Drexel Hill, PA (US);
Joseph Anthony Perrotto, Landenberg, PA (US);
Moshe Oren, Waltham, MA (US);
Ronald Jack Riegert, Newark, DE (US);
E.I. du Pont de Nemours and Company, Wilimingon, DE (US);
Abstract
A waveguide sensing element has a substrate having an input opening adapted to house an input optical fiber and an output opening adapted to house an output optical fiber. The input optical fiber transmits electromagnetic radiation, and the output optical fiber emits the electromagnetic radiation. The waveguide sensing element also has a guiding layer disposed adjacent the substrate. The guiding layer has a beveled end face. The angle of the bevel is chosen so that the guiding layer selects only those modes within a given range--i.e., high order modes. This increases the spectral absorption measurement sensitivity as compared to a waveguide sensing element which uses the complete mode spectrum. Such a highly sensitive waveguide sensing element has been found to be particularly useful as an internal reflection spectroscopic sensing element. Moreover, the waveguide sensing element of the present invention is particularly useful in a process environment, where the corrosive effects of chemicals make on-line spectral absorption measurements difficult. Thus, the waveguide sensing element of the present invention may be rear-fired, which is particularly attractive from a process seal integrity standpoint.