You will discover generally two possible reasons to the powerful refractive index variation on mild irradiation: heating from the LiNbO3:Fe substrates and, For that reason, from the LC inside the microchannel, and director reorientation in the electric subject induced by mild within the LiNbO3:Fe substrates. could be consulted in Appendix https://-lithiumniobatecrystal57902.blog2freedom.com/32433493/lithium-niobate-crystal-for-dummies