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:
May. 10, 2022
Filed:
Apr. 28, 2021
Amazon Technologies, Inc., Seattle, WA (US);
Jeff Clark Adams, Seattle, WA (US);
Donald Mitchell Cornwell, Bellevue, WA (US);
AMAZON TECHNOLOGIES, INC., Seattle, WA (US);
Abstract
Light is modulated at a source to encode data. An additional tracking signal is imposed on the light using polarization modulation (PM). PM modulates one or more values of polarization rotation or polarization ellipticity of the light. These values may be dithered within constraints to provide a specified modulation index at the optical receiver, without impairing the encoded data. At the optical receiver, a polarization analyzer is used to recover the tracking signal, converting the polarization modulation to amplitude modulation. For example, after the light passes through the analyzer, an array of optical photodetectors detects the changes in apparent intensity resulting in the interaction between the light and the analyzer that correspond to the tracking signal. Due to a high modulation index, the recovered signal exhibits a high signal to noise ratio (SNR). The high SNR improves a noise equivalent angle, improving tracking performance.