Lasers and Optical Line Terminations for Passive Optical Networks

Abstract

The present invention relates to a laser for a passive optical network and optical line terminal with the laser. A distributed feedback laser is made with an indium, arsenic, nitrogen and gallium alloy as an active layer material. Through tuning the component of each element in the indium, arsenic, nitrogen and gallium alloy, the laser produces laser comprising two coherent laser wavelengths at the same time, and the two coherent laser wavelengths have the same amplitude, signal to noise ratio and line width. The laser wavelengths generated by the laser are increased with the increase of the nitrogen element in the indium, arsenic, nitrogen and gallium alloy and are increased with the increase of the temperature of the indium, arsenic, nitrogen and gallium alloy. With the random distribution of the nitrogen atom in the indium, arsenic, nitrogen and gallium alloy and the fluctuation of the content of the nitrogen element, the broadening of a guide band bottom is generated, thus a nitrogen localized state cluster is caused near the guide band bottom to generate direct lasing. Based on the optical line terminal of the laser provided by the invention, the laser and the optical line terminal have the advantages of low cost and low power consumption, and the network upgrade and tenability are convenient.

Description

technical field [0001] The present invention relates to optical communication technology, in particular to a laser used in a communication system for a passive optical network and an optical line terminal. Background technique [0002] Wavelength Division Multiplexing Passive Optical Network (WDM-PON: Wavelength Division Multiplexing Passive Optical Network) is considered to be an evolution version for the next generation PON (NG-PON2: Next Generation PON). Through dedicated uplink and downlink wavelength allocation, WDM technology provides virtual point-to-point fiber connections for multiple users. However, the extensive development of WDM-PON still needs to overcome some obstacles. One of the most pressing issues is the design of the optical line terminal (OLT: Optical Line Terminal) laser transmitter. Since the Full Service Access Network Forum (FSAN: Full Service Access Networks) has recently standardized the system requirements of WDM-PON, in this WDM-PON system, NG-...

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Problems solved by technology

[0005] 2) Due to the randomness of broadband ASE light, the characteristics similar to noise and the bandwidth of the channel after spectrum cutting is very wide, it will cause chromatic dispersion, and will seriously reduce the performance of the WDM-PON system with spectrum cutting (for example, intersymbol interference, limited power budget)

[0006] 3) Chromatic dispersion enhances the residual intensity noise (EIN: Excess IntensityNoise) caused by ASE and ASE beating, thus limiting the performance of the system and increasing the receiving bit error rate

[0008] 5) Due to the wide channel bandwidth after spectrum cutting, the spectrum utilization rate is low

[0009] 6) There is multi-mode coexistence in the channel after cutting, which leads to the enhancement of nonlinear effect

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