Measurement of Zeeman Shift of Cesium Atoms Using an Optical Nanofiber

Nanofibers have many promising applications because of their advantages of high power density and ultralow saturated light intensity. We present here a Zeeman shift of the Doppler-broadened cesium D_2 transition using a tapered optical nanofiber in the presence of a magnetic field. When a weak magnetic field is parallel to the propagating light in the nanofiber, the Zeeman shift rates for different circularly polarized spectra are observed. For the \sigma^+ component, the typical linear Zeeman shift rates of F=3 and F=4 ground-state cesium atoms are measured to be 3.10(\pm0.19) MHz/G and 3.91(\pm0.16) MHz/G. For the \sigma^- component, the values are measured to be -2.81(\pm0.25) MHz/G, and -0.78(\pm0.28) MHz/G. The Zeeman shift using the tapered nanofiber can help to develop magnetometers to measure the magnetic field at the narrow local region and the dispersive signal to lock laser frequency.