Gain Enhancement Of Polymer Waveguide Amplifier Based On Nayf4 : Er3+, Yb3+ Nanocrystals Using Backward Pump Scheme

Optical waveguide amplifiers based on NaYF4 : Er3+, Yb3+ nanocrystals prepared by high-temperature thermal decomposition method with forward and backward pump schemes are designed. The gain characteristics of the two schemes are compared through simulation and experiment. For an input signal power of 0.1 mW and a pump power of 270 mW, relative gains of 5 and 5.6 dB are obtained by forward and backward pumping, respectively, in a 9-mm-long waveguide at a wavelength of 1530 nm. Simulation and experimental results show that the gain of backward pumping was higher than that of forward pumping by 12%. The utilization rate of pump light power is greatly improved, which is beneficial to the optimization design of waveguide amplifiers.