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. 15, 1983
Filed:
Jun. 03, 1980
Alfred J Thelen, Santa Rosa, CA (US);
Optical Coating Laboratory, Inc., Santa Rosa, CA (US);
Abstract
A thin film optical filter having a bandpass reflectance characteristic with one of the transition wavelength edges thereof being non-polarizing for radiation incident at a preselected non-normal angle. The filter comprises a transparent substrate and a multilayer thin film optical coating provided on one surface thereof. The optical coating includes a preselected number of alternate layers of a first higher refractive index dielectric material and a second lower refractive index dielectric material arranged as a sequence of dielectric multilayer stacks with intervening spacer layers formed of one of the dielectric materials. The optical thickness of the spacer layers is detuned from half-wave optical thickness to shift either the low wavelength transition edges or the high wavelength transition edges for the separate bandpass response characteristics for the two principal polarization planes substantially into alignment with each other. Various other dielectric stack designs utilizing detuned layers to accomplish the same alignment of wavelength transition edges are described. Simplex and duplex fiber optic communications systems utilizing non-polarizing edge filters of the thin film type are also disclosed.