基于Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)可饱和吸收体的锁模光纤激光器

摘要

Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)薄膜具有宽光谱吸收和高稳定性的特点。在金镜上采用磁控溅射制备了40 nm厚的Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)薄膜,将其在150℃下退火20 min,退火后Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)由非晶态转变为晶态。测试发现晶态Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)可饱和吸收体的调制深度提高到了原来的1.4倍,基于晶态Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)可饱和吸收体实现了脉冲宽度为1.52 ps、信噪比为47 dB的光纤锁模激光器。制备了40、60、80 nm的Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)薄膜,分析表明,随着Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)薄膜厚度的增加,光吸收率明显增加,这说明Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)薄膜的光学性质具有可控性,Ge_(2)Sb_(1.5)Bi_(0.5)Te_(5)材料在超快激光器中有应用潜力。