John Furneaux

Cavity dispersion tuning spectroscopy of tellurium near 444.4 nm

We present saturation absorption spectroscopy of transitions in Te2 near 444.4 nm. These spectra were taken using a blue diode laser locked to a Fabry–Perot (FP) cavity that is in turn locked to a Zeeman-stabilized helium–neon laser. Tuning of the diode laser frequency is accomplished by N2 pressure tuning of the FP cavity. The result is a tuning frequency that is proportional to the dispersion of the index of refraction between the helium neon and diode laser wavelengths. We assess the stability of the blue laser frequency by scanning over a single Te2 absorption line repeatedly over a 48 h period. This work is motivated by our desire to produce a versatile frequency-locked source of radiation for use in molecular optical polarization experiments.