Ultra wideband, high sensitivity magneto-optic field sensor

Using the bismuth rare-earth iron garnet thick films we have demonstrated a magneto-optic (MO) field sensor. The sensor made of all dielectric materials is nearly noninvasive, and is operated at room temperature. The sensor's sensitivity is scalable; the same sensor design can be used for a low-field sensor to measure fields below nano-Tesla or for a high-field sensor to measure several hundred Tesla. The highest sensitivity that we have achieved with the sensor is about 30 pico-Tesla/(Hz)$^{1/2}$. Presently its frequency range is limited from DC to 2 GHz. We have carried out several different experiments with this sensor to explore a few interesting applications, such as electromagnetic signal interception tests over a very broad frequency range. In this presentation we will report our experimental results obtained from this MO field sensor.