A new method for measuring refractivity-based pressure changes using a dual Fabry-Perot cavity utilizing a single laser with off-set sideband locking to the second cavity. The method thus far has shown sensitivity and resolution of 4 mPa.
In short a method to improve upon the current FLOC system, for measuring pressure based on refractivity changes, by using a single laser and direct measure of the difference between the lasers without heterodyne measurement.