PRECISE QUANTIZATION OF PHASE CONTRAST MICROSCOPE FOR OBSERVATION OF A BIOLOGICAL SAMPLE USING LIQUID CRYSTAL PHASE MODULATOR

相差显微镜(PCM)是观察生物样品的关键设备。但传统的相变显微镜不适用于定量观察。我们已经有了一个想法，通过使用可变移相器，如液晶器件，而不是固定的相位板来量化相衬图像。1)利用向列相液晶(LC)移相器的共光路干涉仪对二维位相物体的位相分布进行了量化。2)为了观察活体生物样品，需要高速的数据访问。研究了表面稳定铁电LC和反铁电LC作为高速移相器的性能。我们发现这些器件为PCM中的移相器提供了所需的特性。3)研究了绿茶的非线性光学特性以及由此产生的相位调制特性。通过改变吸收功率，可以实现从0到2pi的全范围相位调制。4)在实验的基础上制作了光管外的等效光瞳平面与物镜分离的PCM。具有对应于环形狭缝的环形电极的LC移相器被放置在光瞳平面上。提出了一种基于+pi/2和-pi/2相移图像相减图像去卷积的相位量化方法，并给出了分析结果。

Phase contrast microscope (PCM) is a key device to observe biological samples. But conventional PCM is not suited for quantitative observation. We have had an idea to quantize phase contrast image by using a variable phase shifter such as liquid crystal devices instead of a fixed phase plate. To realize the idea, following investigations have been done.1) A common path interferometer with nematic liquid crystal (LC) phase shifter was equipped to quantize phase distribution of a 2-D phase object. Accuracy of 30/lambda was attained.2) To observe live biological samples, high speed data access is required. Surface stabilized ferro-electric LC and antiferro-electric LC were investigated as high speed phase shifters. We found that these devices prepare required characteristics for phase shifters in PCM.3) Nonlinear optical properties of green tea extra and resultant phase modulation properties were investigated. Full range phase modulation from 0 to 2pi is possible by changing absorbed power. Applications of this phenomena as a self-align phase filter were demonstrated.4) A PCM made on experimental basis having an equivalent pupil plane out of the optical tube separated from the objective lens was equiped. The LC phase shifter having a ring-shape electrode corresponding to the ring slit is placed on the pupil plane. Phase quantization method based on deconvolution of a subtracted image between +pi/2 and -pi/2 phase shift images was proposed and analyzed results were demonstrated.