Fig. 4: Bandwidth and wavelength ranges of different optical amplifiers.
From: Ultra-broadband optical amplification using nonlinear integrated waveguides
a, State-of-the-art bandwidth of continuous-wave optical amplification in the near-infrared regime based on both stimulated-emission and nonlinear optical platforms. b, Theoretical gain spectra of OPAs based on optimized single-mode nonlinear rib Si3N4 integrated waveguides pumped at wavelengths of 1,305 nm (red) or 1,550 nm (green). Both Si3N4 waveguides have the same rib and slab thicknesses (H1 = 300 nm and H2 = 500 nm) and can be integrated on the same wafer but for different widths of 1,600 nm and 1,828 nm. The waveguide lengths are 2 m with an assumed propagation loss of 0.6 dB m−1. BDFA, bismuth-doped fibre amplifier; EDFA, erbium-doped fibre amplifier; PDFA, praseodymium-doped fibre amplifier; PPLN, periodically poled lithium niobate; QD, quantum dot; QW, quantum well; SOA, semiconductor optical amplifier; TDFA, thulium-doped fibre amplifier.
