A single-frequency, diode-pumped Nd:YLF laser at 657 nm: a frequency and intensity noise comparison with an extended cavity diode laser

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORWe report on a continuous wave, diode-pumped, intracavity frequency-doubled Nd:YLF (yttrium lithium fluoride) single-frequency ring laser designed for high-resolution spectroscopy of the calcium intercombination transition at 657 nm. We measured its frequency modulation (FM) and amplitude modulation (AM) noise and compared it with an extended cavity diode laser (ECDL). The Nd: YLF laser has much lower FM noise, extending to 50 kHz in comparison with 5 MHz for the ECDL, and slightly higher AM noise, transferred from the pump diode laser. This characterization is important for the design of servo-systems for frequency or intensity stabilization, and also for quantum optics experiments. A Nd: YLF laser at 657 nm can become an attractive high-power 'local oscillator' for a calcium optical clock, with a fundamental 'telecom wavelength' that can be directly used for remote transfer in optical fibers.We report on a continuous wave, diode-pumped, intracavity frequency-doubled Nd:YLF (yttrium lithium fluoride) single-frequency ring laser designed for high-resolution spectroscopy of the calcium intercombination transition at 657 nm. We measured its frequency modulation (FM) and amplitude modulation (AM) noise and compared it with an extended cavity diode laser (ECDL). The Nd: YLF laser has much lower FM noise, extending to 50 kHz in comparison with 5 MHz for the ECDL, and slightly higher AM noise, transferred from the pump diode laser. This characterization is important for the design of servo-systems for frequency or intensity stabilization, and also for quantum optics experiments. A Nd: YLF laser at 657 nm can become an attractive high-power 'local oscillator' for a calcium optical clock, with a fundamental 'telecom wavelength' that can be directly used for remote transfer in optical fibers.23214FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP [2006/53713-0]CEPOF [2005/51689-2]2006/53713-0; 2005/51689-2Sem informaçãoSem informaçãoThis work was supported by FAPESP (grant No. 2006/53713-0), CEPOF (grant No. 2005/51689-2), Fotonicom, CNPq and CAPES/COFECUB. We thank Richard Fox from NIST/Boulder for providing the AR-coated diode lasers

Ra+ ion trapping:toward an atomic parity violation measurement and an optical clock

A single Ra+ ion stored in a Paul radio frequency ion trap has excellent potential for a precision measurement of the electroweak mixing angle at low momentum transfer and as the most stable optical clock. The effective transport and cooling of singly charged ions of the isotopes Ra-209 to Ra-214 in a gas filled radio frequency quadrupole device is reported. The absolute frequencies of the transition 7s(2)S(1/)2-7d(2)D(3/2) at wavelength 828 nm have been determined in Ra-212-214(+) with ≤19 MHz uncertainty using laser spectroscopy on small samples of ions trapped in a linear Paul trap at the online facility Trapped Radioactive Isotopes: µicrolaboratories for fundamental Physics (TRIµP) of the Kernfysisch Versneller Instituut

Towards a precise measurement of atomic parity violation in a single Ra+ ion

A single trapped Ra +  (Z = 88) ion provides a very promising route towards a most precise measurement of Atomic Parity Violation (APV), since APV effects grow faster than Z 3. This experiment promises the best determination of the electroweak coupling constant at the lowest accessible energies. Such a measurement provides a sensitive test of the Standard Model in particle physics. At the present stage of the experiment, we focus on trapping and laser cooling stable Ba +  ions as a precursor for radioactive Ra + . Online laser spectroscopy of the isotopes 209 − 214Ra +  in a linear Paul trap has provided information on transition wavelengths, fine and hyperfine structures and excited state lifetimes as test of atomic structure calculations. Additionaly, a single trapped Ra +  ion could function as a very stable clock

Hyperfine structure of the 6d(2)D(3/2) level in trapped short-lived Ra-211,209(+) ions

The hyperfine structure of short-lived trapped Ra-211,209(+) ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B of the 6d(2)D(3/2) level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of Ra-211(+). These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks. (C) 2011 Elsevier B.V. All rights reserved

Test of Lorentz invariance in beta decay of polarized Na-20

Background: Lorentz invariance is key in our understanding of nature, yet relatively few experiments have tested Lorentz invariance in weak interactions.Purpose: Our goal is to obtain limits on Lorentz-invariance violation in weak interactions, in particular rotational invariance in beta decay.Method: We search for a dependence of the lifetime of Na-20 nuclei on the nuclear spin direction. Such directional dependence would be evidence for Lorentz-invariance violation in weak interactions. A difference in lifetime between nuclei that are polarized in the east and west direction is searched for. This difference is maximally sensitive to the rotation of the Earth, while the sidereal dependence is free from most systematic errors.Results: The experiment sets a limit of 2 x 10(-4) at 90% C.L. on the amplitude of the sidereal variation of the relative lifetime differences, an improvement by a factor 15 compared to an earlier result.Conclusions: No significant violation of Lorentz invariance is found. The result sets limits on parameters of theories describing Lorentz-invariance violation