Enhancement of 1.53 μm emission band in NaYF₄: Er³⁺,Yb³⁺,Ce³⁺ nanocrystals for polymer-based optical waveguide amplifiers

NaYF₄:Er³⁺,Yb³⁺,Ce³⁺ nanocrystals (NCs) were synthesized by using a solvothermal approach. Under the excitation of a 980nm laser, the 1.53μm emission band of Er³⁺ ions in the NCs was enhanced by 6 times after codoping Ce³⁺ ions owing to the efficient energy transfer between Ce³⁺ and Er³⁺: ⁴I11/2 (Er³⁺)+ ²F5/2 (Ce³⁺) → ⁴I_13/2 (Er³⁺)+ ²F_7/2 (Ce³⁺). By dispersing the NaYF4:Er³⁺,Yb³⁺,Ce³⁺ NCs into SU-8 2005 polymer matrix, we constructed Er³⁺-doped polymer-based optical waveguide amplifiers (EDPOWAs) and measured their performances. The measured optical gain of the EDPOWA doped with NaYF4: Er³⁺,Yb³⁺,Ce³⁺ NCs was enhanced by ~2dB in comparison with that doped with NaYF₄:Er³⁺,Yb³⁺ NCs. These results showed that NaYF₄:Er³⁺,Yb³⁺,Ce³⁺ NCs are promising candidates for building high gain EDPOWAs.