Stability, Reproducibility, and Absolute Wavelength of a 633-nm He–Ne Laser Stabilized to an Iodine Hyperfine Component

Abstract

A 633-nm He-Ne laser has been stabilized on a hyperfine component of an absorption line of natural iodine vapor by means of a servo system utilizing the zero crossing of the third harmonic of an applied modulation frequency. In its present form the laser has a 1000-sec stability of 1 x 10(-11) lambda, and by virtue of the great reduction in background offset problems resulting from the third harmonic servo, a reproducibility without manual interference of 2 x 10(-10) lambda; improvement in both of these characteristics appears straightforward. The absolute wavelength measured against the Kr(86) standard is 632, 991.398 +/- 0.003 pm.

Optical frequency measurement: 40 years of technology revolutions

“…Our NBS/NIST frequency measurement [23] was confirmed by Layer et al [19] and later improved by several labs. Precision 633-nm wavelength measurements, made by NRC [24] in Canada, NPL [25] in the UK, NRLM [26] in Japan, PTB [27] in Germany and the NBS [28] in Gaithersburg, could be then used to "measure" the speed of light. Similar frequency and wavelengths measurements were made by NPL [29] for a CO laser.…”

Development of a Traceable Laser-Based Displacement Calibration System with Nanometer Accuracy

“…For maximum traceability, the measured displacement must be traced to the standard of length as directly as possible. In this case the standard laser, which is an iodine stabilised He-Ne laser [5]. and the sensor undergoing calibration are connected by only two elements i.e.…”

Laser wavelength measurements

“…Usually several interference maxima from each source are recorded simultaneously (by chopping at different frequencies) as the path difference changes slowly. Air pressure scanning, either at atmospheric pressures with a piston [Rowley and Wallard, 1973;Blaney et al, 1977] or from vacuum with a controlled leak Hanes et al, 1973;Ito and Tanaka, 1978;$chweitzer et al, 1973], is the most usual way of achieving a smooth linear scan. Problems of nonlinearity arise from the linear rate of volume (rather than pressure) change with piston scanning and from temperature changes induced by the pressure changes.…”

“…Systematic errors may also occur owing to the use of separate amplification systems for the two radiations, which may have slightly different time responses introducing different signal delays, particularly if the fringes have different widths [Rowley and Wallard, 1973]. Such electronic problems are avoided in the photographic recording arrangement of Baird et al [1973] and Hanes et al [1973], which uses a spectrograph with a linearly moving photographic plate behind the pinhole to record the intensity changes of both radiations simultaneously. A fundamental disadvantage of continuous scanning methods for a high-finesse interferometer is that it is only for a small fraction of the total recording time that any significant optical flux is detected.…”