Beat frequency measurement of the stabilized He-Ne laser 633 nm calibration in SNSU-BSN

Abstract

In the metrology area, typical stabilized lasers are used as length primary standard. KIM-1, i.e. the iodine stabilized He-Ne laser in National Measurement Standards Laboratory-National Standardization Agency of Indonesia (SNSU-BSN) has been traceable to SI through CCL-K11 inter-laboratory comparison. The result was suitable for KIM-1 to be used as the length primary standard in SNSU-BSN. Beat frequency measurement has been applied in the optical frequency and wavelength calibration system for stabilized He-Ne laser 633 nm using KIM-1 as a reference standard. In the calibration replica, a dual-frequency mode (Agilent 5519B) took a role as DUT laser, which emits a pair of beams with a central wavelength of 632.991 354 nm in the vacuum with frequency difference 3.4 to 4.0 MHz and ±0.02 ppm stability for a typical lifetime. As a measurement result, the beat frequencies of the 1st and 2nd polarized beam of Agilent 5519B against KIM-1 are (121.33±0.06) MHz and (118.59±0.06) MHz.

The Surface Plate Calibration Comparison Based on The Grid Method

“…There are a few different methods that can be used to evaluate the flatness of a surface plate. The most typical way to assess whether a surface is flat is to utilize an instrument capable of detecting small angles, e.g., an autocollimator, a laser interferometer, laser scanning, or a leveltronic [15][16][17][18][19] .…”

MEASUREMENT UNCERTAINTY OF THE OPTICAL WAVELENGTH CALIBRATION 633 nm BY BEAT FREQUENCY MEASUREMENT METHODS

“…KIM-1 is iodine stabilized He-Ne laser (Neoark Beat frequency measurement method (Leach, 2014) had been applied on the optical wavelength calibration in SNSU-BSN, i.e. frequency comparison between KIM-1 as reference laser and UUC laser (Hapiddin et al, 2020). The other method is a direct measurement method, usually for non-stabilized He-Ne laser calibration.…”