Fig. 2: Amplifier design.
a Relative power fraction in the transverse magnetic (TM) mode that is contained in the Tm3+:Al2O3 gain layer (colorscale, purple contours) and mode-area in the gain layer (dashed black contours) in dependence of the Tm3+:Al2O3 layer height and the Si3N4 waveguide width; cf. “Methods” for definition of the mode-area. The locations of the gain waveguides ("gain"), bends ("bend") and tapers ("taper") in the parameter space are indicated. b Group velocity dispersion (GVD) (colorscale, dashed black contours); axes and labels as in (a). c Simulated intensity profiles for different Si3N4 waveguide widths as they occur in gain, bent and tapered waveguide sections. Their positions along the adiabatic taper-profile are indicated. The simulations are based on a finite-element method model.
