APPARATUS AND A METHOD FOR EXTRACTING A CLOCK OF AN OPTICAL SIGNAL, PARTICULARLY FOR EXTRACTING A STABLE CLOCK BY SIMULTANEOUSLY EXTRACTING CENTRAL AND SIDE PEAK WAVELENGTHS AND BEATING THEM, AND ENHANCING THE TRANSMISSION DISTANCE OF AN OPTICAL SIGNAL BY AMPLIFYING A SIZE OF THE SIDE PEAK

• Main Authors: HAN, GI HO, KO, JE SU, CHO, HYEON U, LEE, WANG JU
• Format: Patent
• Language: English; Korean
• Published: 08.12.2004
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

PURPOSE: An apparatus and method for extracting a clock of an optical signal is provided to generate a stable clock by restraining an unnecessary optical component from being extracted between desired two optical components. CONSTITUTION: An optical signal arrived at a receiving end is amplified one time in a pre-amplifier(300) and then is dividedly transmitted into a data path and a clock extraction path in a 2x2 photocoupler(310). The optical signal passing to the data path is photoelectric-converted in a photodiode(330) and then inputted to a data restoring circuit. As for the optical signal used for the clock extraction, a central wavelength and a specific side peak dropped as low as a clock frequency are simultaneously reflected in an optical filter(340) having a specific reflection spectrum, proceed back to the 2x2 photocoupler(310), are amplified in a clock amplifier(350), pass through an ASE(Amplified Spontaneous Emission) filter(360) for noise cancellation, and then are detected as a beating signal in a photodiode(370).