Chakraborty Dipanjan, Georgiev Rosen, Toal Vincent, Naydenova Izabela, Cody Dervil, Martin Suzanne
Opt Express. 2024 May 20;32(11):20385-20400. doi: 10.1364/OE.522326.
The holographic recording of gratings that have very large diffraction angles and/or slants is challenging because recording requires beam angles that are not possible without the use of prisms. However, by using a recording wavelength that is different from (usually shorter than) the intended operating wavelength, it is possible to record with less challenging beam angles. In this paper, a recently developed model that allows systematic investigation of the potential and limits of this wavelength-shift recording technique is extended to include a reflection format. Transmission and reflection recording options are compared systematically for the first time, and it is shown that in reflection recording, some couplers can be recorded more easily when the recording wavelength is longer than the operating wavelength. This opens up new design options for previously challenging regions of the spectrum. Experimental validation of the reflection version of the model is carried out by holographic recording in reflection mode at 532 nm in Bayfol HX 200 photopolymer, demonstrating the coupling of blue light.
记录具有非常大衍射角和/或倾斜度的光栅的全息图具有挑战性，因为记录所需的光束角度在不使用棱镜的情况下是不可能实现的。然而，通过使用与预期工作波长不同（通常较短）的记录波长，可以用难度较小的光束角度进行记录。在本文中，一个最近开发的模型被扩展到包括反射格式，该模型允许对这种波长偏移记录技术的潜力和限制进行系统研究。首次系统地比较了透射和反射记录选项，结果表明，在反射记录中，当记录波长大于工作波长时，一些耦合器可以更容易地被记录。这为以前具有挑战性的光谱区域开辟了新的设计选项。通过在Bayfol HX 200光聚合物中以532 nm的反射模式进行全息记录，对该模型的反射版本进行了实验验证，证明了蓝光的耦合。
