Multi-light-source frequency stabilization system and method in multi-subcarrier system

Abstract

The invention discloses a multi-light-source frequency-stabilization system and method in a multi-subcarrier system, and relates to the field of photo-communication. The multi-light-source frequency-stabilization system comprises n independent laser devices, an N*2 combiner, two arrayed waveguide gratings, n sets of detection devices and n feedback circuits, wherein the N>=n>=1, the n independent laser devices are used as a multi-wavelength light source, the N*2 combiner converges n paths of light with the different wavelengths, and evenly outputs the light to the two arrayed waveguide gratings, the arrayed waveguide gratings conduct smoothing and output two paths of monitoring light corresponding to different light sources, each detection device comprises two photodiodes which respectively receive the two paths of monitoring light corresponding to the same light source, and the feedback circuits are respectively connected with the detection devices and the laser devices corresponding to the feedback circuits, conduct comparison on two luminous powers detected by each detection device and conduct fine adjustment on the output wavelength of the laser devices corresponding to the feedback circuits according to the result. The multi-light-source frequency-stabilization system can be used in a DWDM and Nyquist-WDM system, the cost is low, and the wavelength intervals of the independent light sources are kept stable.

Description

technical field [0001] The invention relates to a DWDM and multi-subcarrier system in the field of optical communication, in particular to a frequency stabilization system and method for multiple light sources in a multi-subcarrier system. Background technique [0002] The development of high-speed optical communication makes the spectral bandwidth resource of optical fiber become tight. In a large-capacity optical transmission system based on DWDM (Dense Wavelength Division Multiplexing) and multi-subcarrier technology, in order to reduce the crosstalk between adjacent channels, it is necessary to keep the channel spacing large enough, which often reduces the spectrum efficiency. Therefore, controlling the wavelength drift of the light source and stabilizing the center wavelength spacing are very necessary for multiple independent light sources in DWDM and multi-subcarrier systems. [0003] Existing multi-subcarrier generation technologies mostly use high-performance narr...

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Problems solved by technology

[0003] Existing multi-subcarrier generation technologies mostly use high-performance narrow-linewidth light sources, and the high cost of a single light source limits its wide commercial use

Mature commercial lasers such as DFB cannot meet higher wavelength control requirements. The central wavelength fluctuation of DFB can reach ±2.5GHz, while the minimum channel spacing set in the high-capacity Nyquist-WDM system based on high-order modulation format is 200MHz. The wavelength shift of individual light sources can easily cause channel overlap

Because the wavelength and frequency of mature light sources such as DFB are not stable enough, and when multiple independent light sources are used to generate multi-carriers, it is necessary to ensure that the wavelength interval of the light sources is stable, so currently mature light sources such as DFB cannot be used stably in the Nyquist-WDM system

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