HAL Id: jpa-00227016
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Submitted on 1 Jan 1987
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STABILIZED Ar-ION LASER FOR INTRA CAVITY EXCITATION OF HIGH RESOLUTION GAS RAMAN
SPECTRA
J. Bendtsen, S. Brodersen, F. Rasmussen
To cite this version:
J. Bendtsen, S. Brodersen, F. Rasmussen. STABILIZED Ar-ION LASER FOR INTRA CAVITY
EXCITATION OF HIGH RESOLUTION GAS RAMAN SPECTRA. Journal de Physique Colloques,
1987, 48 (C7), pp.C7-767-C7-767. �10.1051/jphyscol:19877190�. �jpa-00227016�
JOURNAL DE PHYSIQUE
Colloque C7, supplbment au n012, Tome 48, decembre 1987
STABILIZED Ar-ION LASER FOR INTRA CAVITY EXCITATION OF HIGH RESOLUTION GAS RAMAN SPECTRA
J. BENDTSEN, S. BRODERSEN and F. RASMUSSEN
D e p a r t m e n t of C h e m i s t r y , A a r h u s U n i v e r s i t y , DK-8000 A a r h u s , Denmark
I n o r d e r t o be a b l e t o measure Raman s p e c t r a o f gases w i t h a r e s o l u - t i o n o f 0.01 cm-1 a Michelson i n t e r f e r o m e t e r w i t h maximum o p t i c a l p a t h d i f f e r e n c e o f 1 m and a beam d i a m e t e r o f 16 cm has been c o n s t r u c t e d . The i n t e n s i t y and t h e w i d t h o f t h e Raman l i n e s a r e dependent o f t h e i n t e n s i t y and s p e c t r a l w i d t h o f t h e e x c i t a t i o n r a d i a t i o n . A i m i n g a t h i g h r e s o l u t i o n Raman s p e c t r a t h e o b v i o u s c h o i c e o f t h e e x c i t a t i o n source i s a s i n g l e moded A r - I o n l a s e r o p e r a t i n g a t 488 nm.
The l a s e r was b u i l t p l a c i n g t h e o p t i c a l components on an o p t i c a l bench o f g r a n i t e . The bench as w e l l as t h e i n t e r f e r o m e t e r i s i s o l a t e d v i b r a t i o n a l l y f r o m t h e surroundings. The c a v i t y i s formed b y a s p h e r i c a l t o t a l l y r e f l e c t i n g m i r r o r and a h a l f Brewster p r i s m separated by 200 cm.
The B r e w s t e r p r i s m i s mounted on t h r e e p i e z o e l e c t r i c ceramics. Mode se- i e c t i o n i s performed b y a s o l i d , uncoated and t h e r m o s t a t e d d t a l o n . The wavelength o f t h e l a s e r i s s t a b i l i z e d b y l o c k i n g i t t o a c o n f o c a l r e f - erence Fabry-Perot i n t e r f e r o m e t e r . The e r r o r s i g n a l i s d i g i t i z e d and used by a m i c r o p r o c e s s o r t o c o n t r o l t h e l e n g t h o f t h e c a v i t y b y means o f t h e p i e z o e l e c t r i c ceramics c a r r y i n g t h e B r e w s t e r prism.
The sample c e l l i s p l a c e d i n s i d e t h e c a v i t y t o o b t a i n t h e h i g h e s t p o s s i b l e i n t e n s i t y . I t c o n s i s t s o f a m e t a l t u b e equipped w i t h p l a n e p a r a l l e l windows p l a c e d p e r p e n d i c u l a r t o t h e l a s e r beam. T h i s c o n f i g u r a t i o n a1 lows t h e n e a r l y D o p p l e r - f r e e f o r w a r d s c a t t e r e d l i g h t i n an a n n u l a r cone determined by t h e s p h e r i c a l c a v i t y m i r r o r and t h e c o l l e c t i n g l e n s t o be c o l l e c t e d and t r a n s m i t t e d t o t h e i n t e r f e r o m e t e r .
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19877190
