Calibrating an ultra-low expansion cavity for high precision spectroscopy from 630 THz to 685 THz using molecular tellurium lines

Abstract

We report on the calibration of a temperature stabilized ultra-low expansion (ULE) cavity using previously measured molecular tellurium and atomic cesium lines. By means of a dual frequency modulation technique, the frequency dependence of the free spectral range of the ULE cavity is measured and was found to vary by less than 60 Hz over the ∼55 THz range of the calibration. This method of calibration enables the ULE cavity to measure absolute frequencies to better than 1.5 MHz.

Spectroscopic study of the 7p1/2 and 7p3/2 states in cesium-133

“…Chen [20] also reported the octopole moment, C = 0.0029(4) kHz. ULE cavity [23]. Dual frequency modulation is used to both stabilize and scan the frequency of the laser light [25].…”

“…Thus scanning the frequency of the high frequency EOM results in scanning the laser itself. The procedure and results for determining the frequency of the ULE cavity modes are described by Patterson et al [23].…”

“…For example, the magnetic dipole constant for the 6p 1/2 state is A = 291.9309 (12) MHz [4]. Johnson et al were able to extract the magnetic dipole, electric quadrupole, and magnetic octopole constants for the 6p 3/2 state: A = 50.28825 (23) MHz, B = −0.4940 (17) MHz, C = 0.56 (7) kHz [11]. The most precise value for the hyperfine constant for the 7p 1/2 state was measured by Feiertag et al [16] and the most precise value for the hyperfine constants for the 7p 3/2 state were measured by Svanberg et al [17].…”

“…In this paper, a frequency doubled titanium sapphire laser stabilized to a calibrated temperature stabilized ultra-low expansion (ULE) optical cavity [23] is used to perform hyperfine Doppler free spectroscopy on the 7p 1/2 and 7p 3/2 states in neutral cesium-133. A simplified Grotrian diagram for this work is shown in figure 1.…”

A simple, low cost and robust method for measurement of the zero-crossing temperature of an ultralow expansion cavity

“…Ultralow expansion (ULE) cavity is a Fabry-Pérot optical interferometer, which is made of ULE material with zerocrossing temperature (ZCT) [1] and coated optical mirrors with high reflectivity. It can provide a stable frequency reference to achieve a narrow laser linewidth [2][3][4][5], and thus becomes a key instrument in many applications, such as optical clock [6][7][8][9], characteristic measurement of light and particle [10,11], gravitational wave detection [12] and frequency criterion [13,14].…”