Refractive index detector using Zeeman interferometry

Abstract
We discuss the theory and error analysis for an ultrasensitive refractive index detector based on the two frequency Zeeman effect laser. Experimental measurements on gases agree fairly well with predictions. With a 5-cm pathlength, the typical interferometry stability is Δn = 8 × 10-9/h. Resolution is Δn = 1 × 10-9.