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arXiv · 1601.00251

A high-finesse Fabry-Perot cavity with a frequency-doubled green laser for precision Compton polarimetry at Jefferson Lab

A. Rakhman·M. Hafez·S. Nanda·F. Benmokhtar·A. Camsonne·G. D. Cates·M. M. Dalton·G. B. Franklin·M. Friend·R. W. Michaels·V. Nelyubin·D. S. Parno·K. D. Paschke·B. P. Quinn·P. A. Souder·W. A. Tobias
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Abstract

A high-finesse Fabry-Perot cavity with a frequency-doubled continuous wave green laser (532~nm) has been built and installed in Hall A of Jefferson Lab for high precision Compton polarimetry. The infrared (1064~nm) beam from a ytterbium-doped fiber amplifier seeded by a Nd:YAG nonplanar ring oscillator laser is frequency doubled in a single-pass periodically poled MgO:LiNbO$_{3}$ crystal. The maximum achieved green power at 5 W IR pump power is 1.74 W with a total conversion efficiency of 34.8\%. The green beam is injected into the optical resonant cavity and enhanced up to 3.7~kW with a corresponding enhancement of 3800. The polarization transfer function has been measured in order to determine the intra-cavity circular laser polarization within a measurement uncertainty of 0.7\%. The PREx experiment at Jefferson Lab used this system for the first time and achieved 1.0\% precision in polarization measurements of an electron beam with energy and current of 1.0~GeV and 50~$\mu$A.

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A. Rakhman, M. Hafez, S. Nanda, F. Benmokhtar, A. Camsonne, G. D. Cates, M. M. Dalton, G. B. Franklin, M. Friend, R. W. Michaels, V. Nelyubin, D. S. Parno, K. D. Paschke, B. P. Quinn, P. A. Souder, W. A. Tobias. 2016-01-03. A high-finesse Fabry-Perot cavity with a frequency-doubled green laser for precision Compton polarimetry at Jefferson Lab. https://doi.org/10.1016/j.nima.2016.03.085

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