A reflective light modulator for optical network unit of twdm-pon system

Abstract

The invention provides an optical network unit reflected light modulator for a TWDM-PON (Time and Wavelength Division Multiplexed Passive Optical Network) system. The reflected light modulator comprises a U-type waveguide and a coupled micro ring resonator, wherein the U-type waveguide comprises a first branch and a second branch; and the coupled micro ring resonator is coupled between the first branch and the second branch and comprises two mutually-coupled ring resonators. The coupled micro ring resonator receives uplink seed indicator optical signals comprising multiple uplink seed wavelengths via the first branch. The coupled micro ring resonator is configured to filter out target uplink seed wavelengths from the uplink seed indicator optical signals, modulate uplink data to the target uplink seed wavelengths so as to form uplink optical signals, reflect the uplink optical signals to an optical line terminal via the first branch, and output the remaining of the uplink seed indicator optical signals to the air via the second branch.

Description

technical field [0001] The present invention relates to a passive optical network (PON), and more particularly, to a reflective optical modulator for an optical network unit of a TWDM-PON system. Background technique [0002] In recent years, a Passive Optical Network (PON) has been widely used to provide high-speed services to users. In order to provide multiple access to end users, Time Division Multiplexing (TDM) technology is applied in the current PON infrastructure. In a TDM-based PON, the transmitter sends an aggregated signal on a single wavelength, and the branching device is an optical splitter that distributes the same signal to multiple Optical Network Units (ONUs), each receiving all downstream signals . Currently, TDM-based EPON or XG-PON can provide up to 10Gb / s capacity. [0003] Recently, FSAN and ITU-T are studying NG-PON2 technology to achieve further increase in bandwidth. NG-PON2 is committed to providing 40Gb / s, even a total transmission capacity of...

AI Technical Summary

Problems solved by technology

Therefore, traditional reflective optical modulators (such as RSOA and FP-LD) cannot meet the bandwidth requirements of future TWDM-PON

[0009] 2) An additional uplink adjustable optical filter is required

This makes the ONU very complex and bulky

And, because of the use of an additional adjustable optical filter, the cost of the ONU will be further increased accordingly

[0011] Therefore, although RSOA and FP-LD are widely used components, their modulation rate is limited within 2.5Gb / s

At the same time, an additional upstream adjustable filter is required for the RSOA-based solution, which will inevitably increase the cost and complexity of the ONU

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