Comb spectrum generation system based on cyclic frequency shift pattern and application method thereof

Abstract

The invention relates to a comb spectrum generation system based on a cyclic frequency shift pattern and an application method of the comb spectrum generation system based on a cyclic frequency shift pattern. The comb spectrum generation system based on the cyclic frequency shift pattern comprises an external-cavity semiconductor laser, a 3 dB coupler, a polarization controller, an intelligence quotient (IQ) modulator, a phase modulator, an optical frequency spectrum analyzer, a cosine microwave signal source, a phase shifter, an erbium-doped optical fiber amplifier, an optical filter, an adjustable optical delay line, a direct current bias supply and a section of optical fiber. Cosine radio-frequency signals, reversed cosine radio-frequency signals, sine radio frequency signals with same frequency, and reversed sine radio frequency signals with same frequency are inputted into the IQ modulator. Down-converted signals of optical carrier can be produced through adding appropriate bias voltage to a direct current electrode. The down-converted frequency is four radio frequency (RF) electrode incoming frequency. Elements of coupled seed light and the down-converted light of the optical carrier are modulated by the IQ modulator in a loop circuit. Flat comb spectrum can be obtained through reasonable gain conditions of the erbium-doped optical fiber amplifier and choices of the optical carrier bandwidth.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to a comb spectrum generation system based on a cyclic frequency shifting method and an application method thereof. Background technique [0002] Access network is an important part of modern communication network. In recent years, access networks, especially optical access networks, have developed rapidly, and concepts such as APON, EPON, GPON, Hybrid WDM / TDM-PON, and OFDM-PON have emerged rapidly. Especially OFDM-PON has aroused people's great attention. The use of optical methods to generate multi-wavelength coherent light sources is the basis for realizing all-optical continuous OFDM-PON communication. At present, it is known that methods such as "photoelectric hybrid modulation multi-harmonic generation technology", "cyclic frequency shifter" and "nonlinear optical spread spectrum" are expected to obtain multi-wavelength coherent light sources. A technology came into bei...

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Problems solved by technology

However, it is basically based on the realization of the ideal environment in the laboratory. From the perspective of system structure, the system is complex and the devices are expensive, so it is difficult to achieve commercialization and practicality; 2) Direct generation method: 16 can be generated internationally. There are few schemes for directly generating flat comb spectrum with root and above numbers, which requires a huge RF drive power, low work efficiency, and difficult to be applied in practice; 3) Frequency shift generation method: the scheme is firstly composed of The University of Ottawa, Canada proposed that the modulator carrier suppression modulation technology is mainly used. The system requires two modulators and a bidirectional optical filter. The system structure is also relatively complicated, and it is difficult to be popularized in practical applications.

The existing comb spectrum generator technology is difficult to meet key requirements such as stability, flatness, and simple structure, and there are still many problems to be solved urgently

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