E and EC Department, PEC University of Technology Sector 12, Chandigarh, India __________________________________________________________________________________________ Abstract: In this paper we have discussed the importance of YDFA and obtained optimized Gain and maintained Noise Figure in single stage and double stage YDFA (Ytterbium Doped Fiber Amplifier) with the help of simulation models of different Lengths (1m, 4m, 6m, 8m and 10m) using pumping wavelength 975nm and 910nm then the results are designed with an influence of various Pump power (0.25, 0.5, 0.75, 1 and 1.5) watt. The offered simulation model consists of input source with 90 channels ranging from (950-1150nm) with power of each channel 10 -9 watt, WDM coupler, pumping source, Ytterbium doped fiber of various length and optical spectrum analyzer to measure output. It simulates maximum noise figure, minimum noise figure, maximum gain, minimum gain, mid-level gain etc. Simulation models given in this paper can be operated with high pump power levels and different parameters like (Gain and Noise Figure) can be optimized without changing values of YDF length, and input source. This paper is divided into six segments. In I segment Introduction of YDF (Ytterbium Doped Fibre), YDFA’S (Ytterbium Doped Fibre Amplifiers) is discussed. In II segment Background of YDFA work is understood and method for our work is discussed, whereas segment III & IV shows the Simulation model details and analysis of multistage YDFA models. Segment V presents the tables, results and discussions. Segment VI presents the conclusion of our simulation work. Lastly, in segment VII future scope of our work is discussed.