Helium-neon laser stabilized on iodine: design and performance.

A helium-neon laser operating at 633 nm was frequency stabilized on a hyperfine component of (127)I(2) with saturated absorption. The stability achieved was 2.5 x 10(-12) at an averaging time of 400 sec. The frequency was reproducible to 5 x 10(-11).

Variable interference reflectors with independently settable wavelength and reflectance.

This paper describes the principles and design of interference reflectors whose reflectance at any desired wavelength can be adjusted continuously over a wide range of reflectances and wavelengths by two independent calibrated adjustments. Some calculated and experimental results are given for reflectors with a reflectance range of 0-90% suitable for interference microscopy, 80-100% for laser research, and 0-2% for low loss attenuators.