title: Hybrid immersion-polarization method for measuring birefringence applied to spider silks.
abstract: A technique for accurate measurement of the principle refractive indices and birefringence for silklike samples is presented. It is based on rotating the linear polarization of the illuminating light on a silk immersed in reference liquid to achieve index matching at the silk/liquid interface. The technique was used to measure the principal refractive indices of a P. eburnus radial silk at different strains. This in turn allows the calculation of strain-optic coefficients. The first measurement of the strain-optic coefficients of spider silk is presented. The technique is more generally applicable to strain-optic study of birefringent micro-optic samples.
authors: MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, Sydney, NSW, Australia. douglas.little@mq.edu.au
authors: Douglas J
authors: DJ
authors: Little
authors: Deborah M
authors: DM
authors: Kane
mesh_terms: D000465:Algorithms; D000818:Animals; D001718:Birefringence; D007101:Immersion; D019476:Insect Proteins / Q000737:chemistry*; D012031:Refractometry / Q000379:methods*; D047011:Silk; D013112:Spiders / Q000737:chemistry*; D013314:Stress, Mechanical
chemical_list: D019476:Insect Proteins; D047011:Silk