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. 10, 1992
Filed:
Nov. 13, 1990
Liang D Tzeng, Fogelsville, PA (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A test apparatus and method is disclosed for determining the absolute noise figure of an optical amplifier. The apparatus comprises an optical receiver and functions to measure the output power of a test noise source, such as a lamp or LED. A plot of input power versus output power yields a linear relationship, with a y-intercept at the test apparatus (first) noise floor (N.sub.0). An optical amplifier to be tested is then inserted in the signal path between the noise source and the receiver. A new plot is generated and a second system noise floor value is determined (N.sub.1). The difference between the two noise floor values (N.sub.1 -N.sub.0) is then defined as the amplifier absolute noise figure (N.sub.A). The inventive technique is equally applicable to semiconductor and fiber optical amplifiers.