Demi onde fonctionnant sur tout le spectre visible. Idéale Holographie en couleurs. Diametre 1/2"= 12.7mm. High contrast half waveplate for the visible bandwidth. Rotate linear polarized light or retard linear polarized light by 1/2 of a wave. A glass laminated component with optically fused multi layer polymers sandwiched in between BK-7 windows....