| | Olympus Microscopy Resource Center: Light and Color - Optical Birefringence |
 | | Birefringence is formally defined as the double refraction of light in a transparent, molecularly ordered material, which is manifested by the existence of orientation-dependent differences in refractive index. |
| | In contrast, birefringence refers to the physical origin of the separation, which is the existence of a variation in refractive index that is sensitive to direction in a geometrically ordered material. |
| | The maximum brightness for the birefringent material is observed when the long (optical) axis of the crystal is oriented at a 45 degree angle with respect to both the polarizer and analyzer, as illustrated in Figure 8(c). |
| www.olympusmicro.com /primer/lightandcolor/birefringenceintro.html (4733 words) |
