提出一种使用同一晶体测量电压、电流、电功率的光传感新原理,并在实验上作了验证.简单的分析表明,适宜这种原理的晶体点群只限有8组,它们具有电光效应、旋光性和法拉第旋转效应,适用于这种原理的实际晶体有石英和BSO(硅酸铋)晶体,BSO最适宜这种原理,这是因为它易于光学调整,并且有很好的温度稳定性,用石英和BSO晶体进行的实验表明,与理论的一致性很好. A new theory of optical sensing of voltage, current and electric power using the same crystal is proposed and verified experimentally.The simple analysis shows that there are only 8 groups of crystal points suitable for this kind of principle, they have electro-optic effect , Optical rotation and Faraday rotation effect, the actual crystals suitable for this principle are quartz and BSO (bismuth silicate) crystals, BSO is most suitable for this principle because it is easy to be optically adjusted and has good temperature stability Experiments with quartz and BSO crystals show good agreement with the theory.