Firstly, coherent spectra of free-induction decay (FID) are studied for ZnO-Nb_2O_5-TeO_2:Er_2O_3 at room temperature using femtoseeond laser pulses with the excitation wavelength of 800 nm.

• 2) 在同样条件下研究了ZnO-Nb_2O_5-TeO_2：Er_2O_3的另一飞秒相干光谱：光子回波。