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:
Aug. 26, 2025
Filed:
Feb. 16, 2022
Centre for Development of Telematics, Kamataka, IN;
Prasanta Halder, New Delhi, IN;
Vivek Kumar, New Delhi, IN;
Roshan Lal Sharma, New Delhi, IN;
Atul Kumar Gupta, New Delhi, IN;
Prashant Kumar Rathore, New Delhi, IN;
CENTRE FOR DEVELOPMENT OF TELEMATICS, Karnataka, IN;
Abstract
The present disclosure relates to the field Quantum Key distribution (QKD) and discloses an apparatus () and method () for adjusting the phase modulator's modulating signal time reference in a phase-based QKD system. The QKD system comprises a pulse generator () that generates optical pulses and a phase modulator () that modulates the phase of each of the pulses. The apparatus () comprises abeam splitter/tap (), a 1-bit delay interferometer (), two photodetectors (), and a processing device (). The splitter feeds the phase modulated optical pulses to the interferometer (). Two photo detectors are connected to the constructive and destructive output legs () of the interferometer (). The photo detectors' output are then converted to digital signals and fed to the processing device (). The processing device () measures the average power at both the legs of the interferometer () to detect delay between optical signal and modulating signal and adjusts the delay to accurately align the phase modulator () with the pulse generator ().