S h a n g h a i I n s t i t u t e o f O p t i c s a n d F i n e M e c h a n i c s , A c a d e m i a S i n i c a G r o w t h o f t h e N o n l i n e a r O p t i c a l O r g a n i c C r y s t a l MMONS ( 3 -m e t h y 1 -4 -met h o x y -4'n 1 t r o s t I 1 b e n e ) f r o m t h e Me 1 t The n o n l i n e a r o p t i c a l o r g a n i c m a t e r i a l MMONS ( 3 -m e t h y l -4 -m e t h o x y -4 -n i t r o --s t i l b e n e ) was r e p o r t e d (TAM e t a l . ) i n 1 9 8 9 t o h a v e t h e h i g h e s t m e a s u r e d p o w d e r SHG e f f i c i e n c y ( 1 2 5 0 t i m e s t h a t o f u r e a ) . The MMONS c r y s t a l s w e r e g r o w n b y t h e s o l v e n t e v a p o r a t i o n m e t h o d f r o m o r g a n i c s o l u t i o n ( B I E R L E I N e t a l . ) . T h e s e a u t h o r s a l s o m e a s u r e d t h e n o n l i n e a r o p t i c a l p r o p e r t i e s . Due t o some a d v a n t a g e s (PAN; M A R C I N I A K , WACLANWEK) m e l t g r o w t h o f org a n i c c r y s t a l i s a l w a y s c o n s i d e r e d a s a p r e f e r e n t i a l m e t h o d . H e r e we p r es e n t r e s u l t s o b t a i n e d w i t h m e l t g r o w t h ( e . g . w i t h t h e K y r o p o u l o s m e t h o d and w i t h t h e B r i d g m a n m e t h o d ) o f MMONS c r y s t a l s . M e l t g r o w t h o f MMONS h a s n o t y e t b e e n r e p o r t e d b e f o r e . We u s e d a s t a r t i n g m a t e r i a l t h a t h a d b e e n p u r i f i e d b y r e c r y s t a l l i z at i o n a n d was p r o v i d e d b y t h e c h e m i s t r y d e p a r t m e n t o f t h e F u d a n U n i v e r s i t y ( C h i n a ) . We also t e s t e d t h e O S C c u r v e o f MMONS s t a r t i n g m a t e r i a l f r o m room t e m p e r a t u r e u p t o 17OOC i n a i r , on w h i c h we knew t h e r e i s o n l y one p h a s e t r a n s i t i o n a t l l O°C , t h e m e l t i n g p o i n t . T h i s r e s u l t s u p p o r t e d u s t o g r o w MMONS c r y s t a l s f r o m t h e m e l t i n a i r . Glass s h i e l d seed clamp S-ed Plexiglas6 insulator Pyrex glass crucible Pyrex glass beakex Melt ThermOCOYPlC Ni-Cr w i r e heater Pedestal F i g . 1. S c h e m a t i c d r a w i n g o f t h e a p p a r at u s f o r t h e g r o w t h o f MMONS c r y s t a l s b y t h e K y r o p o u l o s m e t h o d 32 Cryst.