The circular intensity differential scattering (CIDS), which is the normalized Mueller matrix element -S14/S11, has been measured from single biological particles as a function of scattering angle. CIDS is valuable for its potential in detecting chiral particles that may include the helical structures of DNA or RNA molecules in biological samples, and as such is a potential method for detecting biological particles. Optical trapping is employed to levitate single particles within a custom-designed elliptical reflector for CIDS measurements. The advantage of optical levitation in light-scattering measurements is that single particles can be suspended in air with sufficient working distance to prevent interference from the suspending apparatus. To measure the phase function, the reflector is used to collect the angle-dependent scattering signals. We demonstrated that we can obtain two-dimensional angular optical scattering (TAOS) patterns that cover a wide angular range from single levitated particles. These TAOS patterns are generated using 532 nm illumination of left-handed and right-handed circular polarizations and recorded from trapped single particles (silica, English Oak, Ragweed, Mulberry, Glycine, and l-Aspartic acid).

中文翻译：

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测量来自单个光学捕获生物颗粒的圆强度差分散射 （CIDS）


圆强度差分散射 （CIDS） 是归一化的 Mueller 矩阵元素 -S14/S11，已从单个生物颗粒中作为散射角的函数进行测量。CIDS 因其在检测手性颗粒方面的潜力而很有价值，这些颗粒可能包括生物样品中 DNA 或 RNA 分子的螺旋结构，因此是检测生物颗粒的潜在方法。采用光阱将单个颗粒悬浮在定制设计的椭圆反射器内，用于 CIDS 测量。光悬浮在光散射测量中的优势在于，单个颗粒可以悬浮在空气中，具有足够的工作距离，以防止来自悬浮装置的干扰。为了测量相位函数，使用反射器来收集与角度相关的散射信号。我们证明我们可以获得二维角度光散射 （TAOS） 图案，该图案覆盖了单个悬浮粒子的宽角度范围。这些 TAOS 图案是使用左旋和右旋圆极化的 532 nm 照明生成的，并从捕获的单个颗粒（二氧化硅、英国橡树、豚草、桑树、甘氨酸和 l-天冬氨酸）中记录下来。