Korea Advanced Institute of Science and Technology

Lg-Nortel Co., Ltd.

Ki-Man Choi

Chang-Hee Lee

Jung-Hyung Moon

Sil-Gu Mun

Jin-serk Baik

Hyun-Sik Min

Keun-Youl Park

Hoon-Keun Lee

The present invention discloses a wavelength-division multiplexing passive optical network (WDM-PON) capable of high-bandwidth transmission for optical signals by using modulation format having high spectral efficiency. The WDM-PON according to the present invention provides a larger capacity and higher bandwidth transmission economically (at lower costs) by using a modulation format where spectral efficiency (a transmission bit number per a unit band width) is high, while using a low noise part of a light source.

Wavelength division multiplexed-passive optical network capable of high-speed transmission of an optical signal by using modulation format having high spectral efficiency

Disclosed is a wavelength division multiplexing passive optical network for simultaneously providing a broadcasting service and a data service by employing a broadband light source, which uses mutually injected Fabry-Perot laser diodes, as well as a central office used for the same.

Wavelength division multiplexing passive optical network for providing both of broadcasting service and communication service and central office used thereof

The present invention relates to a wavelength-division multiplexed passive optical network (WDM-PON) which embodies wavelength-independence of wavelength-locked Fabry Perot-Laser Diode (F-P LD). A WDM-PON of the present invention comprises an optical fiber being used for optical transmission to and from a broadband light source (BLS) with a low noise characteristic; first arrayed waveguide Gratings (AWG) for filtering light transmitted from the BLS which is oscillated in a plural mode into a group of n numbers wherein the first AWG have a bandwidth broader than a bandwidth of one mode of the BLS; n F-P LDs outputting wavelength-locked light by light being injected through the first AWG; a circulator bypassing and outputting wavelength-division multiplexed signals which are inputted through the first AWG and the optical fiber; and second AWG de-multiplexing the WDM signals into a group of n numbers wherein the second AWG have a bandwidth broader than the bandwidth of the BLS to be injected, wherein the number n is either the number of output ports of the first or second AWG or the number of channels of the WDM signals.

Wavelength-division multiplexed passive optical network for embodying wavelength-independent operation of wavelength-locked Fabry-Perot laser diodes by injecting a low noise broadband light source

The present invention relates to an optical modulation method and optical modulation system of a wavelength locked Fabry Perot-Laser Diode (FP-LD) by injecting a broadband light source (BLS) using mutual injection of FP-LDs. More specifically, the present invention relates to a novel modulation technology which embodies a wavelength locked FP-LD capable of being used as an economic light source in an optical network based on a wavelength-division multiplexing passive optical network (WDM-PON). According to the present invention, a light modulation system is suggested comprising: BLS being constructed by mutual injection between two FP-LDs and an optical fiber being used for light transmission; first AWG for filtering light from a plurality of oscillation modes of the BLS into n group; n FP-LDs outputting wavelength locked light which is divided through the first AWG; an encoder being provided at a transmitting end of a subscriber to which the output from the first AWG is transmitted; a circulator outputting light which is inputted through the first AWG; second AWG de-multiplexing WDM signals from the first AWG into n group; and a decoder being provided at a receiving end to which the output from the second AWG is transmitted. Therefore, the present invention makes it possible to provide a more economic light source for WDM-PON subscribers by embodying a wavelength locked FP-LD by injecting a low-cost BLS.

Optical modulation method and system in wavelength locked FP-LD by injecting broadband light source using mutually injected FP-LD

Disclosed is a broadband light source (BLS) necessary to implement wavelength-locked Fabry-Perot (FP) laser diodes (LDs) applicable to an optical subscriber network The BLS is based on a method using mutual injection of low-cost FP LDs and a method using FP LDs undergoing chirping. A power level of a light emitting diodes (LED), an erbium-doped fiber amplifier (EDFA), or a super luminescent diode (SLD) used as the conventional BLS is low and its cost is high, such that the conventional BLS is inefficient. However, the present invention can easily implement a low-cost BLS using proposed FP LDs.

Broadband light source using fabry perot laser diodes

The present invention discloses a network architecture for upgrading a legacy time division multiplexing-passive optical network (TDM-PON) to a wavelength division multiplexing-passive optical network (WDM-PON) based next-generation passive optical network (next-generation PON), wherein the legacy TDM-PON comprises: a central office (CO) having a first optical line termination (OLT); a remote node (RN) having a splitter; a single mode fiber (SMF) connecting the first OLT and the splitter; and a first group of one or more optical network terminations (ONTs) being connected to the splitter by a first group of one or more distribution fibers, and wherein the network architecture further comprises: in case that the next-generation PON is a WDM-PON, a first apparatus for combining and splitting wavelength bands being positioned between the SMF and the first OLT, in order to add a second OLT to be used for the WDM-PON within the CO or within another CO which is located in a position different from the CO, while sharing the SMF; a second apparatus for combining and splitting wavelength bands being positioned at a front terminal of the splitter; and an arrayed waveguide grating (AWG) being connected to the second apparatus for combining and splitting wavelength bands within the RN, and being connected to a second group of one or more ONTs by a second group of one or more distribution fibers within the RN or within another RN which is located in a position different from the RN.

Method and network architecture for upgrading legacy passive optical network to wavelength division multiplexing passive optical network based next-generation passive optical network

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Daegu, South Korea

Ki-Man Choi