Research On Gain Enhancement Of Piber Optical Parametric Amplifier Via Controlling Ideler Light

Optical amplifier plays an important role in the modern optical communication system. Fiber optical parametric amplifier which is based on the theory of four wave mixing possesses some advantages, such as providing high gain over wide wavelength range, high signal gain within larger bandwidth, low noise figure, phase sensitivity and so on. Therefor the research of the Fiber optical parametric amplifier has attracted increasing attencion recently as a hot. In the optical fiber the phase changes and the energy cyclical shifts, it is necessary to implement the phase matching for the realization of the gain enhancement of the signal wave. In order to implement the phase matching and enhance the amplification gain, a cascade configuration by inserting a fiber Bragg grating between two high nonlinear fibers is used in this paper. Then the Fiber optical parametric amplifier is studied as follows:Combing the four-wave-mixing coupling equations, the transfer matrix of the cascade structure (idler light modulator and fiber optical) dual pump Fiber optical parametric amplifier are derived when considering the different boundary condition, then the expression of output power, phase and gain of the signal are given. Meanwhile, based on the phase matching method which by changing the power and phase of the idler to compensate the phase mismatch, simulating the response of the signal amplified gain caused by the changes of the idler phase、idler power and the cascade position of the idler light modulator, the regulation of parametric gain with idle light is obtained.Designning the idler light modulator to enhance the amplified gain of the single signal, using fiber Bragg grating as idle light modulator. The requirements of parameters of the idler light modulator and the cascade position to enhance the amplified gain of the signal are got by numerical calculation; Combing the coupling equations the expression of transmissivity and phase of the fiber Bragg grating are derived, with the transmission spectrum of the fiber Bragg grating and the requirements of the idler light modulator, simulating the signal gain of the cascade structure, the numerical calculation results show that fiber Bragg grating with reasonable parameters can be used as the idler light modulator to improve the gain of the signal light.