A novel proposal for ultra-high resolution and compact optical displacement sensor based on electromagnetically induced transparency in ring resonator

In this paper a novel method for ultra-high-resolution, compact and tunable optical displacement sensor using ring resonator and electromagnetically induced transparency (EIT) is proposed. The introduced technique uses ring resonator as an interesting element including high quality factor. We show that the proposed sensor can easily detect well below nanometer ranges. It is shown that the proposed idea of using EIT the resolution of the sensor is so high for displacement below mm range and for ranges larger than mm the sensitivity of the proposed sensor in both EIT and traditional cases is same approximately. Also, the proposed sensor is optically tunable. So, depends on required resolution optical control field can be used to tune the sensitivity of the proposed device.