Fu Jinxin, Yoon Beom-Jin, Park Jung Ok, Srinivasarao Mohan
School of Materials Science and Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332, USA.
Center for Advanced Research on Optical Microscopy (CAROM), Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332, USA.
Interface Focus. 2017 Aug 6;7(4):20170016. doi: 10.1098/rsfs.2017.0016. Epub 2017 Jun 16.
A new optical method is proposed to investigate the reflectance of structurally coloured objects, such as butterfly wing scales and cholesteric liquid crystals. Using a reflected-light microscope and a digital single-lens reflex (DSLR) camera, we have successfully measured the two-dimensional reflection pattern of individual wing scales of butterflies. We demonstrate that this method enables us to measure the bidirectional reflectance distribution function (BRDF). The scattering image observed in the back focal plane of the objective is projected onto the camera sensor by inserting a Bertrand lens in the optical path of the microscope. With monochromatic light illumination, we quantify the angle-dependent reflectance spectra from the wing scales of by retrieving the raw signal from the digital camera sensor. We also demonstrate that the polarization-dependent reflection of individual wing scales is readily observed using this method, using the individual wing scales of . In an effort to show the generality of the method, we used a chiral nematic fluid to illustrate the angle-dependent reflectance as seen by this method.
提出了一种新的光学方法来研究结构色物体的反射率，如蝴蝶翅膀鳞片和胆甾相液晶。使用反射光显微镜和数码单反（DSLR）相机，我们成功测量了蝴蝶单个翅膀鳞片的二维反射图案。我们证明这种方法能够测量双向反射分布函数（BRDF）。通过在显微镜的光路中插入一个伯特兰透镜，在物镜后焦平面观察到的散射图像被投射到相机传感器上。在单色光照明下，我们通过从数码相机传感器中检索原始信号来量化来自蝴蝶翅膀鳞片的角度相关反射光谱。我们还证明，使用这种方法，通过蝴蝶的单个翅膀鳞片可以很容易地观察到单个翅膀鳞片的偏振相关反射。为了展示该方法的通用性，我们使用手性向列型流体来说明通过该方法观察到的角度相关反射率。
