Abstract

Recently, single crystals of organic and organometallic salts¹-³ have been shown to possess extremely large second order (χ⁽²⁾) NLO effects leading to a high second harmonic generation (SHG) efficiency. The naturally non-centrosymmetric crystal structures of these compounds eliminates the need for external poling as required for guest-host polymeric systems. Furthermore, these salts have a high optical damage threshold and sufficient stability with respect to temperature to withstand many conventional semiconductor fabrication processes. In particular, highly pure single crystals of the salt, 4'-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST)¹, have been shown to have a value of χ⁽²⁾ at least 10³ times greater than that of urea.

© 1995 Optical Society of America