It was noted that monocrystalline diamond, grown by chemical vapour deposition, often exhibited strain-induced birefringence arising from bundles of edge dislocations lying almost parallel to the [001] growth axis. The birefringent pattern changed when the crossed-polarizers were rotated with respect to the underlying lattice. For polarizers parallel to <110> directions, the birefringence pattern consisted of four bright petals with dark arms along <110>. For polarizers parallel to <100>, the birefringence pattern consisted of eight petals of weaker intensity with dark arms along <110> and <100> directions. The birefringence intensity was evaluated by using isotropic elasticity theory and it was found that these patterns could be explained by a specific dislocation arrangement which was consistent with X-ray topographic studies. Theory of the Birefringence Due to Dislocations in Single Crystal CVD Diamond. H.Pinto, R.Jones: Journal of Physics - Condensed Matter, 2009, 21[36], 364220