Abstract:
A photodetector is provided. The photodetector includes first metal layers in which optical signals are converted into electric signals; first vias formed between the first metal layers and doped areas which include doped areas on both ends of an optical waveguide and a doped area on a growing portion, which absorbs a light signal transmitted through the optical waveguide; second metal layer in which optical signals are converted into electric signals; and second vias formed between the first metal layers and the second metal layers.
Abstract:
Provided is a method of selecting a wavelength of an optical network unit including selecting a pre-loaded default wavelength as an available wavelength candidate or the wavelength that has been changed when a preset wavelength changing condition is satisfied as the available wavelength candidate, acquiring frame synchronization for a downstream signal having the same wavelength as the selected available wavelength candidate, and transmitting a registration request message to an optical line terminal (OLT) from which the downstream signal has been transmitted when the frame synchronization is acquired, assigning the available wavelength candidate to an available wavelength used for communication with the OLT and registering the terminal in the OLT when a registration allowance message is received from the OLT.
Abstract:
A wavelength tuning time measurement apparatus and method for a multi-wavelength passive optical network (MW PON) are provided. The wavelength tuning time measurement apparatus for measuring a wavelength tuning time of a wavelength-variable light source included in the MW PON system includes an optical filter configured to pass only light of a certain wavelength bandwidth and a photo detector configured to sense light passing through the optical filter. The wavelength tuning time is a time taken from a time when a wavelength change signal is transferred to the wavelength-variable light source, to a time when light starts to be successively sensed by the photo detector.
Abstract:
A wavelength-division multiplexing optical communication system and a method for measuring optical performance of an output signal for the system. The optical communication system includes: a service-provider device; a local node; and a plurality of subscriber devices. The service-provider device includes: a plurality of first optical transceivers; a first optical multiplexer/demultiplexer (OD/OM) connected to the plurality of first optical transceivers; and a seed-light source providing seed light. Each subscriber device includes a second optical transceiver. The local node connects the service-provider device and the plurality of subscriber devices to each other using aDWDM link comprising: a second multiplexer/demultiplexer (OD/OM); and a single-mode optical fiber for transmission. Here, the optical intensity of an output signal of the second optical transceiver is determined by compensating for the value of the loss caused when the output signal passes through the second OD/OM of the local node.
Abstract:
Provided are a passive optical network reach extender based on a wavelength tunable optical module and a method thereof. According to an embodiment of the invention, a passive optical network reach extender includes a first optical splitter configured to receive an optical signal from an optical line terminal and split the signal into optical signals having a multiplexed wavelength, a wavelength tunable remote relay configured to receive the optical signals split from the first optical splitter, and select and control an available wavelength for each port, a wavelength multiplexer configured to multiplex a wavelength of the optical signal output from the wavelength tunable remote relay, and a second optical splitter configured to split the optical signal multiplexed by the wavelength multiplexer into a plurality of optical network units.
Abstract:
The TWDM-PON system includes a service provider equipment configured to comprise a plurality of Optical Line Terminals (OLTs), wherein each OLT provides a service in a TWDM scheme; a subscriber equipment configured to comprise a plurality of an Optical Network Units (ONUs), wherein each of the plurality of ONUs utilizes a service provided from one of the plurality of OLTs using an optical signal of an arbitrary wavelength; an Optical Division Network (ODN) configured to transmit multi-wavelength downstream optical signals and multi-wavelength upstream optical signals; and a Reach Extender (RE) configured to comprise at least one of a downstream optical amplifier and an upstream optical amplifier, wherein the downstream optical amplifier is configured to amplify the multi-wavelength optical signals simultaneously, and the upstream optical amplifier is configured to amplify the multi-wavelength optical signals simultaneously.
Abstract:
An optical layer monitoring apparatus and method thereof are provided. According to an embodiment of the present invention, an optical layer monitoring apparatus including an optical time domain reflectometer (OTDR) function so as to monitor an optical path of a passive optical network (PON), and a method for improving accuracy of measured monitoring results using the optical layer monitoring apparatus are provided. Therefore, it is possible to enable a user to continuously detect distortion or attenuation along the optical path, and to quickly recover from the distortion or attenuation along the optical path when distortion or attenuation is detected.