Simulation And Research Of Ytterbium And Erbium Ions Co-doped Waveguide Amplifier Gain Characteristics

With the rapid development of optical communication technology and integrated optoelectronics, the research of optical waveguide amplifiers used in optical communications has drawn more and more attentions. Optical waveguide have many merits such as: high gain, small volume, compact structure, convenient integration and low loss. Other loss apparatus can be integrated easily with erbium doped optical waveguide amplifier and ytterbium and erbium ions co-doped phosphate waveguide amplifier. Considering these advantages, ytterbium and erbium ions co-doped phosphate waveguide amplifier will become more and more popular in future optical communication. The higher concentration of ions asked by optical waveguide amplifier at excited energy level brings on up-conversion. Ytterbium doped optical waveguide amplifier can reduce up-conversion and increase the gain of optical waveguide amplifier. Efficiency of pumping and characteristic of waveguide gain are increased by using ytterbium and erbium ions co-doped phosphate waveguide amplifier.Considering the structure of energy level and transition processes of the ions, rate equations and transmitting equations of quasi-four energy level system of ytterbium and erbium co-doped phosphate waveguide amplifier have been presented and analyzed. Efficiency of pumping power, concentration of ytterbium and erbium ions and the gain of waveguide amplifier had been analysed in theoretical. And some other factors which affect the optical waveguide amplifier have also been discussed and simulated in Matlab software.The rate equations and transmitting equations is solved by using Runge-Kutta methods. Concentration of ytterbium and erbium ions, waveguide length, ions of energy levels and gain of optical waveguide amplifier are analysed by using numerical simulation methods. The relationship between waveguide gain and pump power, concentration of ytterbium and erbium ions are researched deeply. Optimal waveguide length and concentration of ytterbium and erbium ions are got through numerical simulation. Reason of appearing optimal waveguide and concentration of ytterbium and erbium ions are explained from the aspect of particle number of energy level. Reasons of omitting particle number of energy level three and four are also analysed, when rate equations are analysed and calculated. Then ways of improving waveguide and decreasing influence caused by up-conversion are brought up. Relationship between gain and yawp of waveguide is given by numerical simulation taking account of waveguide yawp equation and explained from aspect of theoretical. The way of how to improve waveguide gain and decrease waveguide yawp at the same time are discussed and given. The parameters of loss of waveguide have been calculated by numerical analysis.