Broadband, unpolarized repumping and clearout light sources for Sr${}^{+}$ single-ion clocks

Abstract

Future transportable optical clocks require compact and reliable light sources. Here, broadband, unpolarized repumper and state clearout sources for Sr+ single-ion optical clocks are reported. These turn-key devices require no frequency stabilization nor external modulators. They are fiber based, inexpensive, and compact. Key characteristics for clock operation are presented, including optical spectra, induced light shifts and required extinction ratios. Tests with an operating single-ion standard show a clearout efficiency of 100%. Compared to a laser-based repumper, the achievable fluorescence rates for ion detection are a few tens of per cent lower. The resulting ion kinetic temperature is 1--1.5 mK, near the Doppler limit of the ion system. Similar repumper light sources could be made for Ca+ (866 nm) and Ba+ (650 nm) using semiconductor gain media.

4 pages, 6 figures

References in corpus (3)

• Frequency ratio of two optical clock transitions in ${}^{171}$Yb${}^{+}$ and constraints on the time-variation of fundamental constants
• Dark-state suppression and optimization of laser cooling and fluorescence in a trapped alkaline-earth-metal single ion
• Unpolarized, incoherent repumping light for prevention of dark states in a trapped and laser-cooled single ion

Cited by in corpus (1)

• Broadband lasers for photo-ionization and repumping of trapped ions