Configurable quaternary optical addition and subtraction method based on PPLN (periodically poled lithium niobate)

Abstract

The invention discloses a method for realizing configurable quaternary optical addition and subtraction method by using cascaded quadratic nonlinearity effects in PPLN (periodically poled lithium niobate), and belongs to the technical field of all-optical information processing. The method comprises the following steps that a cSFG / DFG (cascaded sum frequency generation / difference frequency generation) effect in the PPLN optical waveguide is utilized, the two paths of light A and B (1550nm waveband) are respectively symmetrical around the QPM (quasi-phase-matching) wavelength of the PPLN, the two paths of light A and B mutually act to generate SFG effects, and SFG light A+B is generated at the 775nm waveband part. The SFG light and the other beam of light C at a 1550nm part generate DFG effects, and novel idle frequency light A+B-C is generated. The phase of the newly generated idle frequency light and the phases of the several original beams of light meet a formula that phi<A+B+C>=phiA+phiB+phiC. The input light is flexibly configured through an optical switch, and the addition and subtraction operation between any two or among three QPSK (quadrature phase shift keying) signals can be realized.

Description

technical field [0001] The invention relates to a method for realizing configurable quaternary optical addition and subtraction by using the cascaded second-order nonlinear effect in the nonlinear device lithium niobate optical waveguide (PPLN) in an optical network, especially in a gateway node, and belongs to all-optical Information processing technology field. Background technique [0002] All-optical signal processing technology is regarded as a very promising technology in the future optical network. With the development of transmission technology in the communication field, broadband Internet has become popular, and the improvement of signal transmission rate and communication capacity has brought many benefits to people. , such as video conferencing, high-definition TV, distance education, etc., but it also brings a lot of pressure to the network. Bear the brunt of the problem is the power consumption. In the wavelength division multiplexing system, it is necessary t...

AI Technical Summary

Problems solved by technology

The existing research on the addition and subtraction operations of QPSK signals only focuses on the fixed number of input signals, and the completed operations can only be A+B, A-B, B-A, -A, -B, A+B-C, A+C-B, B+ C-A, A+B+C and -C (A, B, C respectively represent three input QPSK signals) or several fixed combinations, it is difficult to achieve configurable output in any combination

At the same time, the existing addition and subtraction operations for QPSK signals are mainly implemented using highly nonlinear fibers (HNLF), which are plagued by the problem of stimulated Brillouin scattering (SBS)

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