A multi-parameter process hybrid cascading method for ultra-low noise optical multi-carrier transmission

Abstract

The invention discloses an ultra-low-noise optical multi-carrier transmission method with multi-parameter process hybrid cascading. The pulse signal generated by the pulse light source enters the photonic crystal fiber, and a forward parametric process occurs to generate multiple sub-carriers; the generated sub-carriers are After the carrier is phase-matched, it is injected into a parametric optical fiber, and the reverse optical parametric process occurs, and the signal optical power is amplified; the amplified signal is detected by the idler light suppression detection module, and when the idler light needs to be suppressed, the signal is returned to the upper In the first-stage phase matcher, the reverse parametric amplification is performed again; when the idler light does not need to be suppressed, the signal is directly injected into the next-stage photonic crystal fiber to continue multi-carrier generation, and then output iteratively for multiple times. The present invention cascades multiple parameter processes and applies them to the generation of multi-carriers. The generated light source has more carriers, lower carrier-to-noise ratio, and relatively stable frequencies between carriers.

Description

technical field [0001] The invention relates to an optical multi-carrier transmitting method, in particular to an ultra-low-noise optical multi-carrier transmitting method in which multi-parameter processes are mixed and cascaded. Background technique [0002] With the rapid development of services such as cloud computing, mobile Internet, and big data, people's demand for network bandwidth is increasing exponentially. Super-channel is the basis for constructing future high-spectrum efficiency and large-capacity optical communication systems. Whether it is in a standard single-mode single-core system or a space-division multiplexing system, it involves the key technology of the super-channel system. The use of multi-carrier light sources can greatly reduce the number of lasers required in super-channel systems, and is an important part of building super-channel systems. Since there is no relative frequency drift between subcarriers, the guard interval can be completely remo...

AI Technical Summary

Problems solved by technology

Based on the cyclic frequency shifter, the light source wavelet number is relatively large and can be adjusted, the frequency interval is adjustable, and the carrier flatness is good, but the disadvantage is that the carrier stability is poor and the carrier-to-noise ratio is also low.

The scheme based on multi-modulator cascading has a complex implementation structure, high modulator cost, limited number of subcarriers generated, and low carrier flatness

Although the multi-carrier light source based on the four-wave mixing effect has a simple structure, the power will gradually decrease when the number of carriers increases. When the power is lower than the four-wave mixing threshold, it cannot be cascaded to further excite new carriers. The number of carriers generated is limited

Although the sub-carrier can be amplified by using the erbium-doped fiber amplifier, and then continue to use the four-wave mixing effect to excite a new carrier, but this amplification method generates more noise, resulting in a low carrier-to-noise ratio of the light source

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