6533b7dafe1ef96bd126ead8

RESEARCH PRODUCT

Sodium vapor cell laser guide star experiments for continuous wave model validation

Ronald HolzlöhnerFelipe Pedreros BustosS. M. RochesterDmitry BudkerSteffan Lewis

subject

Physicsbusiness.industryAstrophysics::Instrumentation and Methods for AstrophysicsPhysics::OpticsSodium layerLaserPolarization (waves)01 natural scienceslaw.invention010309 opticsLaser linewidthOpticsLaser guide starlaw0103 physical sciencesContinuous wavebusinessAdaptive optics010303 astronomy & astrophysicsCircular polarization

description

Recent numerical simulations and experiments on sodium Laser Guide Star (LGS) have shown that a continuous wave (CW) laser with circular polarization and re-pumping should maximize the fluorescent photon return flux to the wavefront sensor for adaptive optics applications. The orientation and strength of the geomagnetic field in the sodium layer also play an important role affecting the LGS return ux. Field measurements of the LGS return flux show agreement with the CW LGS model, however, fluctuations in the sodium column abundance and geomagnetic field intensity, as well as atmospheric turbulence, induce experimental uncertainties. We describe a laboratory experiment to measure the photon return flux from a sodium vapor cell illuminated with a 589 nm CW laser beam, designed to approximately emulate a LGS under controlled conditions. Return flux measurements are carried out controlling polarization, power density, re-pumping, laser linewidth, and magnetic field intensity and orientation. Comparison with the numerical CW simulation package Atomic Density Matrix are presented and discussed.

https://doi.org/10.1117/12.2232524