Er 3+ – Yb 3+ codoped polymeric optical waveguide amplifiers

Codoping of erbium $({\mathrm{Er}}^{\text{3+}})$ and ytterbium $({\mathrm{Yb}}^{\text{3+}})$ rare-earth ions in polymer was studied for optical amplifier applications. The absorption spectrum confirms that the presence of ${\mathrm{Yb}}^{\text{3+}}$ ions enhances the absorption efficiency of ${\mathrm{Er}}^{\text{3+}}$ ions. Typical ${\mathrm{Er}}^{\text{3+}}$ luminescence at ∼1540 nm wavelength was observed, and the full width at half maximum bandwidth is ∼47 nm wide. Multimode ${\mathrm{Er}}^{\text{3+}}–{\mathrm{Yb}}^{\text{3+}}$ codoped polymeric channel waveguides were fabricated using electron beam direct writing. With an input signal power of <−18 dB m, an optical gain of 13 dB at a wavelength of 1533 nm was measured in an 18 mm long multimode channel waveguide.