news july 2009

High m-value polarizing supermirror: high reflectivity meets high polarization

Recently, SwissNeutronics performed a campaign to improve the performance of Fe/Si polarizing supermirror. The preparation process could be refined by a careful investigation of the influence of various deposition parameters on the growth of the supermirror. The achieved improvements motivated us to test the new recipes for a high m polarizing supermirror. Therefore, we produced a Fe/Si supermirror with m = 4.5 on 11-Jul-09. The spin dependent reflectivity and the polarization of the mirror are shown below. The reflectivity reaches 75% at the critical edge of the supermirror. The polarization is on a very high level across the entire range of the supermirror with an average polarization of 0.987 from m = 1.5 to 4.5.

The substrates for the test had a format of 50 mm x 450 mm. These high performance supermirror are now available for our customers to realize new polarizing devices.