Nathan Lundblad

High power single frequency 780nm laser source generated from frequency doubling of a seeded fiber amplifier in a cascade of PPLN crystals

We report on the generation of over 900 mW of tunable cw light at 780 nm by single pass frequency doubling of a high power fiber amplifier in a cascade of two periodically poled Lithium Niobate (PPLN) crystals. Over 500 mW is generated in the first crystal. In the limit of low pump power, we observe an efficiency of 4.6 mW/W2-cm for a single crystal, and 5.6 mW/W2-cm for a combination of two crystals, with an enhancement of the doubling efficiency observed with two crystals due to the presence of second harmonic light from the first crystal acting as a seed for the second. We have frequency locked this laser source relative to a rubidium D2 hyperfine line and demonstrated its utility in a sophisticated laser cooling apparatus.

Two-species cold atomic beam

We generate a bright atomic beam containing laser-cooled rubidium and cesium, and we use this beam to load a mixed-species ultrahigh-vacuum (UHV) magneto-optical trap. We have characterized our two-species atomic beam over a range of operating conditions, and we obtain similar atom fluxes for each species. Within the UHV trap, interspecies inelastic collisions are observed in the form of enhanced decay rates of a given species in the presence of a second trapped species. We analyze the trap decays to obtain a loss rate due to heteronuclear cold collisions, and we compare our result to similar measurements in vapor-cell traps Phys. Rev. A 63 , 033406 (2001).

Clocks and Accelerometers for Space Tests of Fundamental Physics

In this chapter we discuss a technology development program at JPL to address the diminished opportunities for experimental tests of fundamental physics in space. By developing instruments that can serve multiple functions, we hope to gain flight opportunities that would otherwise be unavailable, due to recent refocusing of the space science mission in support of manned flights. We discuss the development of a liter-sized clock based on trapped mercury ions that can serve one-way navigation functions, as well as provide high stability for sensitive tests of general relativity, and possible variation of fine structure constant. We also describe progress in the development of an atom interferometer-based gravity gradiometer. This instrument is aimed at providing detailed subsurface mapping of earth and planetary bodies. It can also be used, with minor modifications, to serve as an instrument to test the equivalence principle. Finally, we report on recent progress for the development of a dual-beam atom laser based on spinor condensates, for future advanced instrumentation supporting fundamental physics studies in space.

Initial experiments with an all-optical spinor BEC

We report on experiments performed with an all-optical spinor BEC, including gravity-aided evaporation, a novel atom laser and a measurement of the density dependence of the spinor dynamics.

Loading, guiding, and manipulating neutral atoms in atom chip magnetic traps

We describe a method of efficiently loading and manipulating neutral atoms in atom chip traps. Cooled 87Rb from a MOT is transported via coil-based magnetic traps into chip-based wire traps and precisely directed in wire-guides.

Spinor dynamics-driven formation of a dual-beam atom laser.

We demonstrate a novel dual-beam atom laser formed by outcoupling oppositely polarized components of an all-optical F = 1 spinor Bose-Einstein condensate whose Zeeman sublevel populations have been coherently evolved through spin dynamics. The condensate is formed through all-optical means using a single-beam running-wave dipole trap. We create a condensate in the magnetic field-insensitive m(F) = 0 state, and drive coherent spin-mixing evolution through adiabatic compression of the initially weak trap. Such dual beams, number-correlated through the angular momentum-conserving reaction 2m(0) ?m(+1) +m(-1), have been proposed as tools to explore entanglement and squeezing in Bose-Einstein condensates, and have potential use in precision phase measurements.