What Does Birefringent Crystal Mean?
What Does Birefringent Crystal Mean?
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各向异性透明晶体如方解石、石英等的折射率，是其固有的特性，称为永久双折射。
In the same way, the polarization condition of the laser beam in a laser crystal with thermally induced birefringence is distorted. The sort of distortion is determined by the situation, since the birefringent axis incorporates a different (e.
As talked about higher than, light that is doubly refracted by means of anisotropic crystals is polarized with the electric vector vibration Instructions in the regular and extraordinary mild waves currently being oriented perpendicular to each other. The actions of anisotropic crystals below crossed polarized illumination within an optical microscope can now be examined.
One of the rays passing by an anisotropic crystal obeys the legal guidelines of regular refraction, and travels Along with the very same velocity in each and every direction from the crystal. This light ray is termed the common ray. Another ray travels which has a velocity which is dependent upon the propagation way inside the crystal, and is termed the amazing ray.
Mild entering an isotropic crystal is refracted at a relentless angle and passes in the crystal at one velocity with no being polarized by conversation Along with the electronic components of your crystalline lattice.
Calcite and various anisotropic crystals act as whenever they were being isotropic resources (for instance glass) below these situation. The optical route lengths of The sunshine rays emerging in the crystal are equivalent, and there is no relative phase change.
The habits of an ordinary light-weight ray within a birefringent crystal can be explained with regards to a spherical wavefront dependant on the Huygens' theory of wavelets emanating from a degree source of light-weight within a homogeneous medium (as illustrated in Determine 5). The propagation of such waves through read more an isotropic crystal happens at constant velocity because the refractive index expert by the waves is uniform in all directions (Determine five(a)).
Note that these axes are perpendicular to one another. The crystal optical axis, which makes an equal angle (103 levels) with all three crystal faces joined within the corner, can be indicated in the lessen part of the crystal. The diploma of birefringence in calcite is so pronounced that the pictures from the letter A shaped via the standard and amazing rays are completely separated. This high standard of birefringence is not observed in all anisotropic crystals.
光纤和其它波导中，采用有效折射率差值描述更好。这与传播常数虚部的差值直接相关。
In some instances, mechanical worry has that effect. That can easily be noticed with a piece of acrylic amongst two crossed polarizers: when worry is applied to the acrylic, one particular observes coloured patterns resulting through the wavelength-dependent outcome of tension-induced birefringence.
而在非线性光学和激光器技术中，双折射则是一些非各向同性透明介质的折射率依赖于偏振方向（即电场方向）的性质。后者的性质时非偏振光束入射到该材料上时产生双折射。
A broad spectrum of elements Exhibit various degrees of birefringence, but the ones of particular desire into the optical microscopist are Those people specimens which have been clear and commonly observed in polarized gentle.
Anisotropic crystals, which include quartz, calcite, and tourmaline, have crystallographically distinct axes and interact with mild by a mechanism that is certainly dependent on the orientation with the crystalline lattice with regard into the incident gentle angle. When gentle enters the optical axis of anisotropic crystals, it behaves within a manner much like the conversation with isotropic crystals, and passes via at just one velocity.
For propagation along the optical axis, the electrical field can only be perpendicular to that axis, making sure that 1 obtains the standard index for any polarization course. In that scenario, no birefringence is expert.
Alternatively, the amazing wave deviates for the left and travels with the electrical vector perpendicular to that in the ordinary wave. Since calcite is actually a negatively birefringent crystal, the ordinary wave could be the slow wave as well as remarkable wave is the rapid wave.