Patent ID: 7532821
Filing Date: 2009-05-12
Classification: H04L

Abstract:
1. An apparatus for optical clock extraction, comprising: an optical circulator for changing a direction of an inputted optical signal; a filter for extracting different frequency components existing a spectrum of the inputted optical signal, removing noise from a reflected and amplified optical signal, and transmitting the resulting signal to the optical circulator, wherein the difference in the frequency components on the spectrum represents a clock frequency; an optical amplifier for performing a primary amplification to equalize two different frequency components outputted from the filter, and performing a secondary amplification on an optical signal reflected and fed back thereto; and a reflector for reflecting the primarily-amplified optical signal to the optical amplifier, wherein the filter is connected between the optical circulator and a first input/output terminal of the optical amplifier, and wherein the reflector is located after a second input/output terminal of the optical amplifier for reflecting the primarily-amplified optical signal to the second input/output terminal of the optical amplifier.