Huang L, Salter P S, Payne F, Booth M J
Opt Express. 2016 May 16;24(10):10565-74. doi: 10.1364/OE.24.010565.
The depth dependent spherical aberration is investigated for ultrafast laser written waveguides fabricated in a transverse writing geometry using the slit beam shaping technique in the low pulse repetition rate regime. The axial elongation of the focus caused by the aberration leads to a distortion of the refractive index change, and waveguides designed as single mode become multimode. We theoretically estimate a depth range over which the aberration effects can be compensated simply by adjusting the incident laser power. If deeper fabrication is required, it is demonstrated experimentally that the aberration can be successfully removed using adaptive optics to fabricate single mode optical waveguides over a depth range > 1 mm.
研究了在低脉冲重复率条件下，利用狭缝光束整形技术以横向写入几何结构制备的超快激光写入波导的深度相关球差。由球差引起的焦点轴向伸长导致折射率变化失真，设计为单模的波导会变成多模。我们从理论上估计了一个深度范围，在该范围内仅通过调整入射激光功率就可以补偿球差效应。如果需要更深的制备，实验证明使用自适应光学技术可以成功消除球差，从而在大于1毫米的深度范围内制备单模光波导。
