Creating a compact low-power laser threshold magnetometer utilizing the NV center in diamond

Laser threshold magnetometry (LTM) promises a path towards significant reductions in optical power and volume for high sensitivity diamond nitrogen-vacancy (NV) magnetometers. LTM utilizes the difference in laser threshold due to intra-cavity diamond absorption while driving the RF spin resonance. Power consumption is directly related to the sizes of the laser spot on the gain chip and the diamond. By confining the spot size, we can drastically reduce the laser threshold pump power needed (up to ~34x for proposed linear cavity design). By physically connecting all the pieces of our sensor, we also reduce laser noise allowing us to approach closer to threshold, therefore increasing our contrast and decreasing our photon shot noise limit.