提出了利用液晶菲涅尔波带透镜实现光学相干层析成像(OCT)动态聚焦的方法。根据扭曲相液晶空间光调制器(TN-LCSLM)的光学特性,设计了适用于OCT动态聚焦的菲涅耳波带透镜。利用TN-LCSLM型菲涅耳波带透镜进行了变焦控制实验,焦距实测结果与设计值比较吻合。此外,本文讨论了采用TN-LCSLM型菲涅耳波带透镜实施动态聚焦涉及到的一些问题。
An approach to realize dynamic focusing in Optical Coherence Tomography (OCT) is proposed by using liquid crystal Fresnel zone lens. Fresnel zone lens suitable for dynamic focusing in OCT is designed based on optical characteristics of Twisted Nematic Liquid Crystal Spatial light Modulator (TN-LCSLM). Experiments on dynamic focusing control of the TN-LCSLM based on Fresnel zone lens are carried out. Measured focal lengths are in good agreement with the designed ones. Discussion on associated problems with the TN-LCSLM based on Fresnel zone lens for dynamic focusing is carried out as well.