Optical rotation, circular dichroism and other manifestations of optical activity are measured routinely for isotropic samples, serving as hallmarks of chirality in applications ranging from the determination of sugar concentrations to the investigation of virus structures. In contrast, measurements of optical activity are seldom reported for anisotropic samples, the main reason being that anisotropic samples usually exhibit linear birefringence, linear dichroism and other effects that convolve with and partially suppress optical activity.

RPC is working in close collaboration with ZEISS on interference-contrast optical activity (ICOA); a new, chirally sensitive imaging technique designed to overcome these difficulties using a subtle interplay of phase, polarisation and intensity [1]. Potential applications include the use of ICOA to help monitor the growth of chiral crystals in the pharmaceutical industry.


  1. R. P. Cameron, U. Vogl and N. Trautmann, Royal Society Open Science 7, 192201 (2020).