Intracavity iodine cell spectroscopy with an extended-cavity diode laser near 633 nm

New technologies applied to visible diode lasers allow stabilization of an extended-cavity system using an internal iodine cell. Preliminary results at wavelengths around 633 nm are encouraging and show that such systems may some day replace the He-Ne lasers now used as frequency standards. The tunability of the diode lasers makes it possible to access iodine transitions which absorb more strongly than those usually used with He-Ne lasers.