Fabrication of PDMS-based volume Bragg gratings by stitching of femtosecond laser filament
Fabrication of PDMS-based volume Bragg gratings by stitching of femtosecond laser filament
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DOI：
10.35848/1347-4065/abe05e
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发表时间：
2021-03-01
影响因子：
1.5
通讯作者：
Watanabe, Wataru
中科院分区：
文献类型：
--
作者：
Homma, Kentaro;Watanabe, Wataru
利用飞秒激光丝拼接技术制作了基于聚二甲基硅氧烷（PDMS）的体布拉格光栅（VBGs）。在PDMS中，由飞秒激光脉冲引起的折射率变化很低（10（-4）到10（-3）的数量级）。因此，VBG厚度是在PDMS中制备高效VBG的关键参数。以提高衍射效率为目的，本文提出了基于PDMS的多层VBG的制备方法。我们使用飞秒脉冲激光器（100 fs脉冲宽度，1 kHz重复频率）产生10 μ m线间距的VBG。通过改变纤维在不同深度处的相对位移和层间距离，可以控制改性区的厚度。通过在PDMS中深度多路复用350 μ m长的介电改性来产生高效VBG。光栅厚度为0.63 mm时，衍射效率达到87.2%。
This work demonstrates the fabrication of poly-(dimethylsiloxane) (PDMS)-based volume Bragg gratings (VBGs) by stitching of femtosecond laser filament. The refractive index change induced by femtosecond laser pulses is low (orders of 10(-4) to 10(-3)) in PDMS. Therefore, the VBG thickness is the key parameter to fabricate high-efficiency VBGs in PDMS. With the intention of increasing diffraction efficiency, this paper presents fabrication of multi-layered PDMS-based VBGs. We produce VBGs with 10 mu m line pitch using a femtosecond pulse laser (100 fs pulse width, 1 kHz repetition frequency). The modified zone thickness can be controlled by arranging the relative displacement of filament at different depths and the distances between layers. High-efficiency VBGs were created by depth multiplexing of 350 mu m long filamentary modification in PDMS. Diffraction efficiency of 87.2% was realized by forming 0.63 mm grating thickness.