NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
E Laub, J Huennekens, R K. Namiotka, Zeina J. Kubarych, I Prodan, J La civita, S Webb, I Mazsa
Abstract
We report the results of an optical-optical double resonance experiment to determine the NaK (3 1PI) state potential energy curve. In the first step, a narrow band cw laser (PUMP) is tuned to line center of a particular 2(A) (1 SIGMA+)(v?, J?) <-- 1(X) (1 SIGMA+)(v?, J?) transition, and its frequency is then fixed. A second narrow band tunable cw Ti-Sapphire laser (PROBE) is then scanned, while (3 1PI) --> 1(X) (1 SIGMA+) violet fluorescence is monitored. The Doppler-free signals accurately map the (3 1PI) (v, J) ro-vibrational energy levels. These energy levels are then fit to a Dunham expansion to provide a set of molecular constants. The Dunham constants, in turn, are used to construct an RKR potential curve. Resolved (3 1PI) (v, J) --> 1(X) (1 SIGMA+) (v?, J?) fluorescence scans are also recorded with both PUMP and PROBE laser frequencies fixed. Comparison between observed and calculated Franck-Condon factors is used to determine the absolute vibrational numbering of the (3 1PI) state levels and to determine the variation of the (3 1PI) --> 1(X) (1 SIGMA+) transition-dipole moment with internuclear separation. The recent theoretical calculation of the NaK (3 1PI) state potential reported by Magnier and Milli? (1996, Phys. Rev. A 54, 204) is in excellent agreement with the present experimental RKR curve.
Laub, E.
, Huennekens, J.
, Namiotka, R.
, Kubarych, Z.
, Prodan, I.
, La civita, J.
, Webb, S.
and Mazsa, I.
(1999),
Experimental Study of the NaK (3 1PI) State, Journal of Molecular Spectroscopy
(Accessed October 9, 2025)