Luminescence and Optical Properties of Tm 3+ :TeO 2 - ZnO-TiO 2 Glasses for Fiber Optic Applications

Transcription

1 Luminescence and Optical Properties of Tm + :TeO - ZnO-TiO Glasses for Fiber Optic Applications İdris Kabalcı 1, Turgay Tay Tuğba Duran, Mustafa Özdemir, Gönül Özen 4 1 Department of Physics Education,, Şanlıurfa, Turkey Department of Chemistry, Anadolu University, Eskişehir, Turkey Department of Physics, Marmara University İstanbul, Turkey 4 Department of Physics, Istanbul Technical University İstanbul, Turkey

2 Outline Motivation Synthesis of Tm + :TeO -ZnO-TiO glass Thermal, Optical and Spectroscopic Measurements Fluorescence Properties Results

3 Volume Glass and Structure Stable Liquid Rapidly cooled liquid (a) Crystalline and Amarphous Structures (b) Glass Crystal Temperature T g T m T g : Glass transition T m : Melting temperature Figure: Atomic arrangement in two dimension (a) crystal and (b) glass. Ref: MAP Silva et al., 00, Journal of Physics and Chemistry of Solids,6, 605. Ref: Yamane and Asahara, Glasses for Photonics, Cambridge Un. Press, 000

4 Glass Types (a) (b) Glass Nonoxide glass Organic polimeric glass Chalco. glass Halogen glass Floride glass Oxide glass Nonsilicate glass Silicate glass (a): Nonsuitable materials for fiber optics (b): Suitable materials for fiber optics TeO glass Low silicate glass

5 Tm + :TeO -ZnO-TiO Glasses Potential applications Fiber-optic nm Infrared fiber nm Physical properties: Low melting temperature High dielectric constant High refractive index Resistant to atmospheric moisture Transmission window in the IR region (0.5-5 m) Low phononenergies: Borate (1400 cm -1 )>Phosphate (1100 cm -1 )>Silica (1000 cm -1 )> Germanate (900 cm -1 )>Tellurite (780 cm -1 ) >Fluorides (500 cm -1 )>Chalcogenides (00 cm -1 ) Ref:

6 Synthesis of Tm + : TeO - ZnO-TiO Glasses Three sets of samples: ytm + : (95-x)TeO -(x) ZnO-5TiO Set 1: x=05, 10, 0, and 0 mol%, undoped. Set : y=1.0 mol, x=05, 10, 0, and 0 mol%. Set : x=0 mol, y=0., 0.5, and 1.0 mol%. Batch size=7 gm Melting temperature=850 0 C (60 minutes, platinum crucible) Rapid quenching between graphite slabs

7 Laser Photonics Lab., Department of Physics Education, Harran Un. Synthesis of Tm + :TeO -ZnO-TiO Chemicals Furnace TeO : % purity,sigma- Aldrich ZnO : 99+% purity, Sigma-Aldrich TiO : 99+% purity, Merck Tm O : 99.9% purity, Aldrich

8 Density (g/cm ) Density measurements Laser Photonics Lab., Department of Physics Education, x (mol%) x mol% ZnO Tellurite glass samples

9 Exo Up Thermal Analysis (DTA) 0 o C/min (1-x)TeO -(x)zno-5tio T p DTA + (T s -T r ) + (d) T g (c) T g T x T p - (b) T g T p1 T p T p T m T s HEATER T r (a) T g T m (a): 5mol% ZnO (b): 10mol%ZnO (c): 0mol%ZnO (d): 0mol% ZnO Temperature ( o C) T m T g : Glass transition temperature T p : Crystallization temperature T m : Melting temperature T s : Sample temperature T r : Reference temperature Ref: (DTA) Prof.Dr. Remzi Gürler, Department of Materials Science, Eskişehir Osmangazi University, Eskişehir

10 Kg Glass Forming Tendency Glass Tendency 0.8 Glass Tendency: K g K g T T c m T T g c x (mol%) Ref: Maharian N.B., Physc. Stat. Sol. (a), 178. p The glass forming tendency is highest at a composition 0 mol.% ZnO

11 Intensity (arb.u) X-Ray Diffraction (1-x)TeO -xzno-5tio (c) : -TeO : -TeO (b) (a) (a): 40 o C, (b): x= o C, (c): x= o C Ref: X-Ray Diffraction, Rigaku, Research Lab.

12 Intensity (arb.u) X-Ray Diffraction (1-x)TeO -xzno-5tio (f) : -TeO : -TeO (e) (d) (d): x=0 490 o C, and (e): x=0 mol,@ 50 o C, (f): x=0 mol% 500 o C

13 Absorbance UV-VIS Absorption Absorption spectrum : (1-x)TeO -xzno-5tio Mott-Davis Theory x=5mol% ZnO x=10mol% ZnO x=0mol% ZnO x=0mol% ZnO ( ) log C( h I 0 l I E n opt ) / h Wavelength (nm) Ref: Perkin Elmer Lamda 5 UV-VIS, M.Durgun, Department of Chemistry,, Şanlıurfa Values of n= ½ and for Direct and indirect transtions, Respectively. Ref: N.F. Mott, E.A. Davis, Electronic Processes in Non-crystalline Materials,Clarendon Press, nd Edition, Oxford, 1979.

14 Absorption Direct Band Gap, E g Indirect Band Gap, E g TZT1 TZT1 TZT TZT TZT TZT TZT4 TZT4 5 4 TZT1 TZT1 TZT TZT TZT TZT TZT4 TZT TZT1: x=5 mol% ZnO : E g =.94; E g =.6 ev TZT: x=10 mol% ZnO: E g =.96; E g =.67 ev TZT: x=0 mol% ZnO: E g =.97; E g =.7 ev TZT4: x=0 mol% ZnO: E g =.0; E g =.74 ev

15 Absorbance Tm + :TeO -ZnO-TiO Absorption spectrum : 1 mol % Tm + : 0.90TeO -0.05ZnO-0.05TiO Energy Level of Tm + 1 D mol% Tm + : (95-x)TeO -xzno-5tio 1 G 4 T=00 o K 1 G F, F F 4 F H 5 F H nm 1470 nm H 5 H Wavelentgth (nm) 1800 nm Ref: M.J.F. Digonnet, Rare-Earth Doped Fiber Lasers and Amplifiers, 199. H 6 Ref: Shimadzu UV-VIS-NIR, T.Tay, Department of Chemistry, Anadolu University, Eskişehir

16 Absorption 1 G 4 F, F 4 H 5 Tm + :TeO -ZnO-TiO Absorption spectrum : 1 mol % Tm + :(TeO ) (1-x-y) -(ZnO) (x) -(TiO ) (y) T=00 o K 1.0mol% Tm + : (TeO ) (1-x-y) (ZnO) (x) (TiO ) (y) x=5mol% H 4 x=10mol% x=0mol% x=0mol% Wavelength (nm)

17 Judd-Ofelt Theory Tm + : 4f-4f transition Laporte rules: u g ; g u Russel Saunders : S+1 L J Judd-Ofelt theory: Intensity parameters (, 4, ), 6 Radiative transition probability, A(J,J ) Radiative lifetime, R Luminescence quantum efficieny, η Branching ratio, (I,J) Ref: B.M. Walsh, NASA Langley Research Center, Erice, Italy (June 005). Tm + : 1s s p d 10 4f 1 5s 5p 6 Ref: R.C. Powel, Physics of Solid-State Laser Materials.

18 Einstein s Coefficient E N ij ( E j Ei ) h B 1 A 1 B 1 B 1U 1 N1 A1N B1U 1 N E 1 N 1 Einstein s Coefficients: A 1 : Spontaneous emission prob. B 1 : Stimulated emission pob. B 1 : Absorption transition pob. U 8 h c 1 exp h kt ed A1 B1 S ( J, J ') hc

19 Judd-Ofelt Parameters Judd-Ofelt intensity 8 e ( parameters n ) N0 ( J, J ) x ch 9n (J 1) ( t) f cal t SLJ U S L J t,4,6 f ( ) d den S ed band ( J, J ) t,4,6 t.0 log 10( I o / I) ( ) l SLJ U ( t) S L J band 8 e ( n ) N0 ed ( )d S ( J, J ) ch 9n (J 1), 4, 6 = Judd-Ofelt intensity parameters c = speed of light, cm/sec; n= refractive index = mean wavelength, SLJ=Quantum number N 0 = Tm + concentration (t) U = irreducible tensor operator

20 Judd-Ofelt Theory A( J, J ) 4 64 e h(j 1) n( n ) 9 x t,4,6 t SLJ U ( t) S L J 1 R J A ( J, J ) W R A ( J, J ) W R F R

21 Intensity Parameters TeO -ZnO-TiO glasses Refractive index =.05 Ref: E.R. Taylor, L.N. Ng, N.P. Sessions, J. Appl. Phys.9(1), , (00). t,10-0 cm x, mol%

22 Luminescence Measurements PbS DETECTOR PREAMPLIFIER LOCK-IN AMPLIFIER SCANNING SPECTROMETER M1 Tm-GLASS L1 CHOPPER DIODE LASER (785 nm) OSCILLOSCOPE COMPUTER Ref: A. Sennaroglu, A. Kurt, Laser Research Lab., Department of Physics,Koç University

23 Intensity Photoluminescence 0.40 T=00 o K 0. mol% Tm F 4 H mol% Tm 1.0 mol% Tm (a) 0. Cross relaxation rates Tm + Tm + F 4 F (b) Pump (785 nm) 1 H 5 H 4 H 5 H (c) Wavelength (nm) H 6 H 6 y = 0. mol % Tm + (a) y = 0.5 mol % Tm + (b) y = 1.0 mol % Tm + (c) Ref: Kabalci I., Özen G., Kurt A., and Sennaroglu A., MRS (Material Research Society), Proc. Volume 89, Boston, 004 x=0mol% ZnO

24 Results 1.0 mol% Tm + Concentration (mol %) R ( s) F 4 R ( s) H 4 E opt1 (ev) E opt (ev) d(g/c m ) Radiative life time decrease for increasing glass compositions Optical energy band gap increases with glass compositions

25 Conclusions x = 5, 10, 0, and 0 mol.% (95-x)TeO -xzno-5tio new glasses doped with Tm + ion are synthesized, Spectroscopic investigation of luminescence in Tm + :TeO -ZnO-TiO as a function of glass composition. Radiative Lifetimes, Radiative transition probabilities and branching ratios: Judd-Ofelt analysis. Energy band gaps (E g ) calculated, Density, UV-VIS, and UV-VIS-NIR measurements were reported for these samples.

26 Collaborators Prof. Dr. Gönül Özen, Physics Department, I.T.U., Maslak, İstanbul, Turkey Prof.Dr. Alphan Sennaroğlu, Laser Research Laboratory, Koç University, Sarıyer, İstanbul, Turkey Prof.Dr. M. Lütfi Öveçoğlu, Ress. Asst. Hasan Gökçe, Department of Metallurgical and Materials Engineering, İ.T.Ü., Maslak, İstanbul,Turkey Acknowledgements This research has been supported by TÜBİTAK, under the project number 108T694.