Phases and Third-Order Optical Nonlinearities in Tetravalent Metallophthalocyanine Thin Films

Abstract

The third-order optical susceptibilities χ₁₁₁₁ ⁽³⁾(-3ω; ω, ω, ω)s f o r t w o d i f f e r e n t p h a s e s i n v a n a d y l a n d t i t a n y l p h t h a l o c y a n i n e (V O P c a n d T i O P c) v a c u u m-d e p o s i t e d t h i n f i l m s a r e d e t e r m i n e d b y o p t i c a l t h i r d-h a r m o n i c g e n e r a t i o n (T H G) m e a s u r e m e n t s a t w a v e l e n g t h s 1543 n m a n d 1907 n m. T h e r m a l a n n e a l i n g c a u s e s a p h a s e t r a n s i t i o n w h i c h a c c o m p a n i e s a r e d s h i f t i n t h e i r a b s o r p t i o n s p e c t r a a n d a n i n c r e a s e i n t h e χ^(3) v a l u e o f 2-5 t i m e s i n V O P c a n d T i O P c f i l m s. T h e e n h a n c e m e n t o f t h e t h i r d-o r d e r o p t i c a l n o n l i n e a r i t i e s i n t e t r a v a l e n t p h t h a l o c y a n i n e f i l m s i s d i s c u s s e d i n t e r m s o f m o l e c u l a r p a c k i n g.