Passive optical network and its optical line terminal optical module

Abstract

The invention discloses a passive optical network and an optical line terminal optical module thereof. The optical module comprises at least two laser transmitting units, wherein each laser transmitting unit comprises a CML (current mode logic) laser device and a driving circuit thereof; the driving circuit in each laser transmitting unit is used for receiving electric signals sent by a switch and driving the CML laser device in the laser transmitting unit to perform laser transmission according to the received electric signals; and the minimal frequency interval of the laser transmitted by the CML laser devices of the different laser transmitting units is not less than 50GHz. As the CML laser devices in an OLT (optical line terminal) are used for controlling the spectrum of the transmitted laser below 0.2nm, thus the center wavelength can be stably locked on an ITU-T (international telecommunications union-telecommunication) grid point, the channel spacing can be reduced, and the purposes of providing more channels, expanding the capacity of a network system and improving the bandwidth of the system can be further achieved.

Description

technical field [0001] The invention relates to optical fiber communication technology, in particular to a passive optical network and an optical line terminal optical module thereof. Background technique [0002] With the continuous growth of users' demand for high-bandwidth services such as high-definition IPTV (Internet Protocol Television, Internet TV), video surveillance, etc., the industry has gradually realized that the existing EPON (Ethernet Passive Optical Network, Ethernet Passive Optical Network) and GPON (Gigabit Passive Optical Network, Gigabit Passive Optical Network) technology is difficult to meet the needs of long-term business development, especially in fiber-to-the-building (FTTB) and fiber-to-the-node (FTTN) scenarios. The optical access network is facing new upgrade requirements in terms of bandwidth, service support capabilities, and access node equipment functions and performance. According to analysis, the per capita bandwidth demand of each family ...

AI Technical Summary

Problems solved by technology

However, the current WDM PON technology is only based on CWDM (Coarse Wavelength Division Multiplexing, coarse wavelength division multiplexing) multiplexing of limited wavelengths (full wave 16 wavelengths, generally only 4 wavelengths in the 1310 band are used), even It is the introduction of DWDM (Dense WaveLength Division Multiplexing, high-density wavelength division multiplexing technology) technology, subject to the limitations of the spectral width and wavelength temperature drift of the externally modulated laser, the channel spacing is only controlled at 100GHz spacing (C-band 45 channels)

That is to say, the existing WDM PON technology still cannot provide enough bandwidth to meet the growing demand of ONU (Optical Network Unit, Optical Network Unit) users for video service bandwidth

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