| In this work, the design, simulation and optimization of a Mach-Zehnder 3-wavelength optical demultiplexer (MZ-3WDM) have been performed using a combination of the effective index method (EIM) and the 2D finite difference vectorial beam propagation method (FD-VBPM). Furthermore, the theoretical design and performance predictions of the demultiplexer are verified experimentally through device fabrication and measurements.;The combination of the effective index method based on the Rung-Kutta method and a finite difference vector beam propagation method (FD-VBPM) provide for a computational design tool that yields useful results. The average extinction ratios of the demultiplexer, which were achieved theoretically for the 980nm, 1310nm and 1550nm wavelengths are 34db, 32db and 26db respectively.;The effect of the wavelength deviations, the error in diffusion time and the error in the waveguides' width, on the extinction ratios were studied. The results of the study indicated that a 20db of extinction ratio for the three wavelengths could be obtained over a bandwidth of 32nm range, a +/-12min error in diffusion time and a +/-100nm error in waveguides' width.;The demultiplexer device is experimentally realized, and was made by a one-step thermal K+ - Na+ ion exchange in soda-lime glass substrate. The measured results of extinction ratios, ranging from 19db to 24db, which were achieved at the three wavelengths agreed reasonably well with the FD-VBPM simulations.;The agreement between the theoretical predictions and the experimental results presented in this work clearly demonstrate the feasibility of the demultiplexer device (MZ-3WDM). |
