Eaton Shane, Zhang Haibin, Herman Peter, Yoshino Fumiyo, Shah Lawrence, Bovatsek James, Arai Alan
Opt Express. 2005 Jun 13;13(12):4708-16. doi: 10.1364/opex.13.004708.
High-repetition rate femtosecond lasers are shown to drive heat accumulation processes that are attractive for rapid writing of low-loss optical waveguides in transparent glasses. A novel femtosecond fiber laser system (IMRA America, FCPA muJewel) providing variable repetition rate between 0.1 and 5 MHz was used to study the relationship between heat accumulation and resulting waveguide properties in fused silica and various borosilicate glasses. Increasing repetition rate was seen to increase the waveguide diameter and decrease the waveguide loss, with waveguides written with 1-MHz repetition rate yielding ~0.2-dB/cm propagation loss in Schott AF45 glass. A finite-difference thermal diffusion model accurately tracks the waveguide diameter as cumulative heating expands the modification zone above 200-kHz repetition rate.
高重复率飞秒激光被证明能驱动热积累过程，这对于在透明玻璃中快速写入低损耗光波导很有吸引力。使用一种新型飞秒光纤激光系统（美国IMRA公司，FCPA muJewel），其重复率可在0.1至5 MHz之间变化，以研究热积累与熔融石英及各种硼硅酸盐玻璃中所得波导特性之间的关系。结果发现，随着重复率的增加，波导直径增大，波导损耗降低，在肖特AF45玻璃中，以1-MHz重复率写入的波导产生的传播损耗约为0.2 dB/cm。当重复率高于200 kHz时，由于累积加热使改性区域扩大，有限差分热扩散模型能准确跟踪波导直径。
