Because of the big difference in refractive indices, 1 ray will go through the crystal at a slower amount than another ray. To paraphrase, the velocity of your slower ray will probably be retarded with respect on the speedier ray. This retardation price (the relative retardation) is often quantitatively identified making use of the next equation:
The polarization dependence of your refractive index can have a range of consequences, some of that are extremely crucial in nonlinear optics and laser technological innovation:
直光纤只有很小的随机双折射，即使这样其中的光传输一段距离后偏振状态也会发生变化。存在保偏光纤，是利用了很强的双折射来抑制这些效应。
If waves with unique polarization directions propagate together inside the waveguide, their section relation is restored following integer multiples on the propagation defeat length.
The normal and remarkable wavefronts in uniaxial crystals coincide at either the slow or the fast axis of your ellipsoid, dependent upon the distribution of refractive indices inside the crystal (illustrated in Figure six). The optical route variation or relative retardation in between these rays is determined from the lag of 1 wave guiding another in surface wavefronts together the propagation course.
In laser technological know-how and nonlinear optics, the phenomenon of birefringence occurs mostly from the context of non-isotropic crystals:
For bulk optical resources, It is additionally widespread to contemplate the difference of refractive indices for The 2 polarization Instructions. The more substantial that difference, the much larger the acquired retardance per millimeter of propagation length.
, along with the refractive index for specified wavelength depends on the relative orientation of electric discipline director and optical axis:
双折射是光束入射到各向异性的晶体，分解为两束光而沿不同方向折射的现象。光在非均质体中传播�?，其传播速度和折射率值随振动方向不同而改变，其折射率值不止一个；光波入射非均质体，除特殊方向以外 ，都要发生双折射，分解成振动方向互相垂直、传播速度不同、折射率不等的两种偏振光，此现象即为双折�?。
For incredible waves, wherever the refractive index depends upon the angular orientation, You will find a spatial wander-off: the way of energy propagation is a bit tilted from that on the k vector.
In contrast, birefringence refers back to the Actual physical origin of the separation, that's the existence of the variation in refractive index that is sensitive to course inside of a geometrically purchased material. The difference in refractive index, or birefringence, among the click here remarkable and standard rays touring via an anisotropic crystal is usually a measurable amount, and will be expressed being an absolute worth with the equation:
A broad spectrum of products Screen varying levels of birefringence, but those of distinct fascination for the optical microscopist are People specimens which might be transparent and easily noticed in polarized light-weight.
Microscopists classically check with this orientation as being a posture of extinction with the crystal, which is crucial being a reference point for pinpointing the refractive indices of anisotropic supplies with a polarizing microscope. By eradicating the analyzer in the crossed polarizing microscope, The only permitted path of sunshine vibration passing throughout the polarizer interacts with only one electrical ingredient during the birefringent crystal.
For propagation alongside the optical axis, the electrical area can only be perpendicular to that axis, in order that one particular obtains the everyday index for almost any polarization course. In that condition, no birefringence is expert.
在激光器技术和非线性光学中，双折射现象通常发生在非各向同性晶体中：