Dependence of @[email protected] of a sample on the type of @[email protected] of the measuring beam. This @[email protected] may be linear, corresponding to linear dichroism (LD) in which the difference in absorption for two perpendicularly linearly polarized beams is measured, \(\Delta A_{\text{l}} = A_{\text{Z}} - A_{\text{Y}}\), or circular dichroism (CD) in which the difference in absorption for left minus right circularly polarized beams is measured, \(\Delta A_{\text{C}} = A_{\text{L}} - A_{\text{R}}\).