Doornbos R M, Schaeffer M, Hoekstra A G, Sloot P M, Grooth B G, Greve J
Appl Opt. 1996 Feb 1;35(4):729-34. doi: 10.1364/AO.35.000729.
We have developed an instrument for determination of the angular light scattering of beads and biological cells. The instrument uses radiation pressure for levitation of particles inside a cuvette. The setup consists of two 780-nm diode lasers in a vertical double-beam trapping configuration. In the horizontal direction a weakly focused 633-nm probe beam is used to illuminate the trapped particle. One can detect scattered light over the range of from - 150 to 150 deg with an angular resolution of 0.9 deg using an avalanche photodiode. With this setup light scattering from polystyrene beads was measured, and the obtained scattering patterns were compared with theoretical scattering patterns from Lorenz-Mie theory. The results show that the setup is stable, gives reproducible patterns, and qualitatively agrees with the calculations. Trapping of biological cells is more difficult than trapping of beads, because smaller forces result from smaller refractive indices. We present an angular scattering pattern measured from a human lymphocyte measured from 20 to 60 deg.
我们开发了一种用于测定珠子和生物细胞角向光散射的仪器。该仪器利用辐射压力使比色皿内的颗粒悬浮。该装置由处于垂直双光束捕获配置的两台780纳米二极管激光器组成。在水平方向，使用一个弱聚焦的633纳米探测光束来照射捕获的颗粒。使用雪崩光电二极管，可以在-150至150度的范围内以0.9度的角分辨率检测散射光。利用该装置测量了聚苯乙烯珠子的光散射，并将获得的散射图案与洛伦兹-米氏理论的理论散射图案进行了比较。结果表明，该装置稳定，能给出可重复的图案，并且在定性上与计算结果相符。捕获生物细胞比捕获珠子更困难，因为较小的折射率会产生较小的力。我们展示了从人淋巴细胞在20至60度范围内测量得到的角散射图案。
