cutoff region
2.Nonlinear optical borates LiB 3O 5,CsB 3O 5 and CsLiB 6O 10 contain B 3O 7 anionic groups as basic structural units. They have similar linear and nonlinear optical features,such as a short ultraviolet cutoff,a relatively large nonlinear optical coefficient and a high optical damage threshold,which make them suitable for frequency conversion in the ultraviolet region.

