Simple Laser Stabilization to the Strontium ${}^{88}$Sr Transition at 707 nm

We describe frequency stabilization of a laser at 707.202 nm wavelength using FM spectroscopy in a hollow cathode lamp. The laser is stabilized to the ${}^{88}$Sr metastable ${}^3{\mathrm{P}}_2$ to ${}^3{\mathrm{S}}_1$ optical transition. The stabilized laser is utilized for laser-cooling and trapping of strontium atoms. We also briefly describe the performance of a polarization spectroscopy lock of our blue MOT laser at 461 nm derived simultaneously from the same hollow cathode lamp.