Ua kapa ʻia ka wikiwiki o ka nalu mua o ka mokulele monochromatic ma kona ʻaoʻao maʻamau. ʻO ka wikiwiki o ka holo ʻana o ka ikehu hawewe māmā i kapa ʻia ʻo ka wikiwiki o ka ray. ʻO ke ala e hele ai ka mālamalama e like me ka nānā ʻana o ka maka o ke kanaka, ʻo ia ke ala e hele ai ka mālamalama.

No ka kristal hoʻokahi non-magnetic, ʻo ka wikiwiki o ka hawewe māmā planar e kū pololei i ke kuhikuhi o ka neʻe ʻana o ka uila. D a me ka ikaika o ke kahua magnetic H, oiai e pili pono ana ka aoao hoolaha ikehu o ka nalu malamalama H a me ka ikaika o ke kahua uila E. ʻO ka dielectric mau o ka anisotropic optical media he tensor papa lua.D a E 'A'ole like like, no laila ke kuhikuhi o ka wikiwiki o ka pae v a me ka wikiwiki laina v_r ʻaʻole kūlike. ʻO ka Angle i komo α ma waena o lākou ua kapa ʻia ka discrete angle, he hana ia o ke kuhikuhi o ka velocity phase (a i ole ray velocity) a me ke kuhikuhi o D (a i ʻole E) (e like me ka mea i hōʻike ʻia ma ke kiʻi ma lalo). ʻAʻole like ka wikiwiki o ka pae a me ka laina laina, a ʻo ka pilina ma waena o lākouv=v_rcosα.

ʻO ka ratio o ka wikiwiki e hele ai ka mālamalama i loko o kahi mānoanoa (c) i kona pae velocity v ma kahi kuhikuhi i hāʻawi ʻia i loko o kahi ʻano ʻano ʻano anisotropic ua kapa ʻia ʻo ka huaʻōlelo refractive no kēlā kuhikuhi. Pela no ka ratio oc i ka mama o ke kukuna ma kekahi aoao n_r=c/v_r ua kapa ʻia ʻo ka ʻōlelo kuhikuhi refractive o ka kukuna ma ia ʻaoʻao.

WISOPTIC papa nalu