FLUORESCENCE DYNAMICS IN SOME SOLID-STATE LASER MATERIALS EMITTING IN THE INFRARED REGION : Ho3+ DOPED LiYF4 SINGLE CRYSTALS AND FLUORIDE GLASSES

(1)

HAL Id: jpa-00227092

https://hal.archives-ouvertes.fr/jpa-00227092

Submitted on 1 Jan 1987

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

FLUORESCENCE DYNAMICS IN SOME

SOLID-STATE LASER MATERIALS EMITTING IN THE INFRARED REGION : Ho3+ DOPED LiYF4

SINGLE CRYSTALS AND FLUORIDE GLASSES

J. Rubin, A. Brenier, R. Moncorge, C. Pedrini, B. Moine, G. Boulon, J.

Adam, J. Lucas, J. Henry

To cite this version:

J. Rubin, A. Brenier, R. Moncorge, C. Pedrini, B. Moine, et al.. FLUORESCENCE DYNAMICS IN SOME SOLID-STATE LASER MATERIALS EMITTING IN THE INFRARED REGION : Ho3+

DOPED LiYF4 SINGLE CRYSTALS AND FLUORIDE GLASSES. Journal de Physique Colloques,

1987, 48 (C7), pp.C7-367-C7-369. �10.1051/jphyscol:1987788�. �jpa-00227092�

(2)

JOURNAL DE PHYSIQUE

Colloque C7, supplbment au n012, Tome 48, dbcembre

1987

FLUORESCENCE DYNAMICS I N SOME SOLID-STATE LASER MATERIALS EMITTING IN THE INFRARED REGION

: ^~ ⁰ ^~

DOPED LiYFq SINGLE CRYSTALS AND FLUORIDE

^'

GLASSES

J. RUBIN, A. BRENIER, R. MONCORGE, C. PEDRINI, B. MOINE, **G. BOULON, J.L. ADAM*, J. LUCAS' and J.Y. HENRY'"**

CNRS U A - 4 4 2 e t C e l p h y r a , U n i v e r s i t e C l a u d e B e r n a r d , Lyon I , 4 3 , B d du 11 n o v e m b r e 1 9 1 8 , F - 6 9 6 2 2 V i l l e u f b a m e C e d e x , F r a n c e

CNRS UA-254, U n i v e r s i t e R e m e s I , F - 3 5 0 4 2 R e m e s C e d e x , F r a n c e

" L E T I , CENG, BP 8 5 X, F - 3 8 0 4 1 G r e n o b l e C e d e x , F r a n c e

I n t h e p r e s e n t work, we r e p o r t on t h e o p t i c a l p r o p e r t i e s 6 f Er3+ and Ho3+ i o n s embedded i n some s o l i d - s t a t e m a t e r i a l s . YLiF4 s i n g l e c r y s t a l s a r e one o f them. The o t h e r c l a s s c o n s i s t s o f f l u o r i d e glasses, well-known f o r t h e i r wide range of t r a n s - parency p a r t i c u l a r l y i n t h e m i d - i n f r a r e d r e g i o n . T h e i r c o m p o s i t i o n s a r e t h e f o l l o - wing : z @ L A : E ~ ~ + : H o ~ + : 57ZrF4

-

34EaF2

-

( s - x - ~ ) L a F

-

4A1F3

-

xHoF3

-

yErF

3 3

BATY :tr3+:Ho3+ : 2013aF2

-

28.75A1F3

-

22.5ThF

-

(28.75-x-y)YF3- xHoF3 - YFrF, 4

BIZYT:E~~*:HO~* : 30BaF2

-

301nF3

-

20ZnF7

-

(10-x-r)YF3

-

?0ThF4

-

xPoF,

--

-

^yErF3.

The s t u d y c o n s i s t s o f r e c o r d i n g and a n a l y z i n g t h e e x p e r i m e n t a l time-dependences o f e m i t t i n g l e v e l f l u o r e s c e n c e s i n t h e i n f r a r e d and v i s i b l e ranges. The o p t i c a l p r o c e s s e s a r e d e s c r i b e d i n terms o f r a t e e q u a t i o n s u h i c h a p p l y because f a s t d i f f u - s i o n i s g e n e r a l l y i n v o l v e d between t h e Er3+ s e n s i t i z e r s .

We have s t u d i e d i n d e t a i l s t h e e m i s s i o n p r o c e s s e s i n ~ rs i n g l y doped YLiF ~ + 4 s i n g l e c r y s t a l s [1,2] and shown t h a t i n h e a v i l y doped samples, energy t r a n s f e r mechanisms o c c u r t h r o u g h s e v e r a l modes i n c l u d i n g u p - c o n v e r s i o n a n d c r o s s - r e l a x a t i o n t r a n s f e r s ( r i g h t p a r t o f f i g u r e 1 ) . The same dynamics i s o b s e r v e d i n t h e f l u o r i d e

3+

.

g l a s s e s . I n p a r t i c u l a r , s e l f - q u e n c h i n g mechanisms w i t h i n E r Tons o f t h e g r e e n f l u o r e s c e n c e o r i g i n a t i n g f r o m 4 ~ 3 / 2 , r e p r e s e n t e d as 4 4 4

4 4 '3/2' 4 1 ~ 5 / 2 + '9/2' 3:~3/2

and S31Z, 4 ~ 1 5 1 2 - 4 ~ 9 / 2 , a r e shown t o be v e r y e f f i c i e n t a s t h e Er c o n c e n t r a t i o n i n c r e a s e s ( t a b l e 1 ) .

The i n f r a r e d f l u o r e s c e n c e p r o c e s s e s o f d i r e c t l y e x c i t e d ~ 0 i o n s were a n a l y z e d ~ '

a s a f u n c t i o n o f t h e ~ 0 c o n c e n t r a t i o n . The i n c r e a s e o f t h e ~ ' 5 I7 l e v e l l i f e t i m e w i t h Ho 3+ c o n c e n t r a t i o n i n YLiF4 and i n f l u o r i d e g l a s s e s o n l y a t low c o n c e n t r a t i o n s , i s i n t e r p r e t e d by a r e a b s o r p t i o n o f t h e 2 p m e m i s s i o n by t h e 5~ g r o u n d s t a t e . Such

8

"03+ c o n c e n t r a t i o n dependence i s n o t o b s e r v e d f o r 'I6. The h i g h Ho3+ c o n c e n t r a t i o n b e h a v i o u r (> 1 I ) f o r 5I i s t h e same a s f o r 5i6 : t h e decrease o f t h e l i f e t i m e i s

7

due t o t h e d i f f u s i o n and t r a p p i n g o f energy.

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1987788

(3)

C7-368 JOURNAL

DE

PHYSIQUE

3+ 3+

A d e t a i l e d a n a l y s i s o f t h e Er +Ho energy t r a n s f e r mechanisms was c a r r i e d

3+ 3+

.

o u t i n YLiF4:Er

,

Ho s i n g l e c r y s t a l s f o r v a r i o u s Laser e x c i t a t i o n s i n t h e e x c i t e d s t a t e s o f ~ ri o n s i n t h e v i s i b l e and i n f r a r e d r e g i o n s ~ +

C

³

1.

I n f l u o r i d e glasses, t h e s e t r a n s f e r s were s t u d i e d o n l y under i n f r a r e d l a s e r e x c i t a t i o n i n t h e 4

'13/2 and 4~,1,2 l e v e l s . The f l u o r e s c e n c e dynamics i s w e l l d e s c r i b e d by o u r models and t h e r e - f o r e q u i t e w e l l u n d e r s t o o d . I n t h e t a b l e 2 a r e g a t h e r e d t h e quantum e f f i c i e n c i e s o f some energy t r a n s f e r s i n t h e i n f r a r e d . S p e c i a l a t t e n t i o n was drawn on t h e d i f f e r e n t e x c i t a t i o n c h a n n e l s which p o p u l a t e 'I7 Lowest e x c i t e d s t a t e o f Ho

3+ ,

owing t o t h e

5 5

p r i m e i n t e r e s t o f t h e 17, I 2 p m i n f r a r e d l a s e r t r a n s i t i o n . Three main chan- n e l s , c a l l e d I R I , I R 2 and RED a r e shown t o be e f f i c i e n t , a s i n d i c a t e d i n t h e l e f t p a r t o f t h e f i g u r e 1. The r e l a t i v e c o n t r i b u t i o n s o f each channel o f e x c i t a t i o n t o t h e 5 I7 L e v e l o f ^~ ⁰ a r e c a l c u l a t e d and a r e r e p r e s e n t e d i n t a b l e 3 a s a f u n c t i o n ^~ ^' o f t h e ~ re x c i t a t i o n l e v e l f o r t h r e e bi-doped 'fLiF4:S0 % E r ~ ' 3+

,

x % ^~ ⁰ ^{( X}^~ = ^' 0.5, 2, 5 ) s i n g l e c r y s t a l s .

ACKNOWLEDGMENTS

T h i s work was 9 u p p o r t e d by t h e DRET g r a n t s # 84.071 and # 85/27?.

REFERENCES

1. R. RUBIFI, A. BREMIER, R. MOFICORGE and C. PEDRINI J. Lumin.

36,

3 9 (1986).

2. A. BREF!IER, J. RUBIF!, R. MOFICORGE and C. PEDRIF!I J. L e s s Common M e t a l s

126,

203 (1P86).

3. J. RUBIW, A. BRENIER, R. MONCORGE and C. PEDRIF!I To be p u b l i s h e d i n J. Phys. Paris, October 1087.

Ex 10"crn-'

t

3+ 3

+

^{? A}

Main c h a n n e l s o f Ho e x c i t a t i o n v i a Er -Ho energy t r a n s f e r and s e l f - w e n c h i n g mechanisms w i t h i n ~ ri o n s ~ +

(4)

T a b l e ^I

T a b l e 2 Ouantum e f f i c i e n c i e s o f eneray t r a n s f e r s

4 5 4 5

(i) VT? : I ~ ~ / ) , ~ ~ - - - a . I ? ? / ? * - 1 7

4 5: 4 4 3+

(ii)

bT2

^:

I,,~

^,2,

^I*..-

^I^,5,7, ^{5 ~ 6}⁽e x c i t a t i o n i n of F r 1

4 5 5

(iii) I j T ? : Ill,,2, 18-4~15,2, - I 6 ⁽e x c i t a t i o n i n 4 ~ 1 1 /2 o f ~ r " ) Samples

YLiF4

*

BIZYT

EPTY

~ r ~ *

50

Q 5 1

i17.75 HO"

0.5

2 5

1 5 9 1

T a b l e 3

P e l a t i v e c o n t r i b u t . o n o f each channel o f e x c i t a t i o n t o t h e 5 ~ 7

3+

L e v e l o f Ho 3+ a s a f u n c t i o n of t h e Er e x c i t a t i o n L e v e l .

53

Exc 4

'13/2 4

11112 4

19"

4~ 9 / 2

-.

-F

bT1

75 93 96 23 76

55

53

tIo3+ c o n c e n t r a t i o n

0.5 f% 2 % 5 Z

I

/)

^T2

50 73 83 1 9 46 24 31

I R 1 100 % IRq

+

I R ?

57% 4x4

I R 1

+

I R 2

922 8%

IR1

+

FED

? ?

100 ID1 X

ljT2

24 3 8 50

--- .

I R 1 100 % I R 1 + I F 2 79% 21%

I R 1 + I R 2 82% 18i:

I P 1

+

PED 8

IR, + I R z 72Z 28X ^,

I R 1 100 % IR1

+

I R 2

94% 6%

I R 1 + I R 2 66Y. 3LI.

I F 1

+

FED 26%

----

74%

IR1 + If?