Investigation of spectroscopic properties and laser oscillation of
oxides ceramics manufactured with SHS-MS method
V.V. Zelenogorsky1, S.S. Balabanov2, Yu.V. Bykov1,
S.V. Egorov1, A.G. Eremeev1, E.M. Gavrishchuk2, I.B. Mukhin1, O.V. Palashov1, E.A. Perevezentsev1, D.A. Permin2
1Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
2Institute of Chemistry of High-Purity Substances, Russian Academy of Sciences, Nizhny Novgorod, Russia
Introduction
Nizhny Novgorod:
• Institute of Chemistry of High-Purity Substances stands for preparation of nano-powders
• Institute of Applied Physics stands for baking and samples benchmarking
www.8lcs.iapras.ru
Y2O3 SHS technique from acetate nitrates complexes
SHS precursor Reaction propagation High-disperse oxide
Metal acetate nitrates were prepared by dissolving oxides in an aqueous solution of acetic and nitric acids:
Self-propagating high-temperature synthesis (SHS) means the synthesis of compounds (or materials) in a wave of chemical reaction (combustion) that propagates over starting reactive mixture owing to layer-by-layer heat transfer
1/2Y2O3 + 3x HNO3 + 3(1-x) CH3COOH Y(NO3)3x(CH3COO)3(1-x) aq
Gyrotron-based system for materials processing
6 kW 24 GHz gyrotron system
Utilization of microwave heating is promising due to absence of resistive heating elements which can contaminate material at high temperatures. The additional advantage of this method is its less energy consumption compared to conventional sintering
Impurity composition of powders was investigated using atomic emission spectrometry with inductively coupled plasma (AES-ICP) iCAP6300 (USA) and revealed no significant differences in impurity composition of both starting powders (see table 2) and sintered ceramics.
Ceramics
Scanning electron microscopy of baked Yb:Y2O3 ceramics
Lanthanum
To produce a highly transparent material during sintering several additives are often used, such as ZrO2, La2O3, Gd2O3 and others. We are using lanthanum oxide.
Selecting the best Lantaniumconcentration
0
5
10
15
20
25
30
0 2.5 5 7.5 10 12.5 15 17.5La2O3, mol. %
1/cm
0
1
2
3
4
5
6
7
8
9
10%
Scattering, 1/cm
Absorption, 1/cm
Reflection, %
Absorption and Luminescence spectrums
0
10
20
30
40
50
60
70
80
90
100
900 950 1000 1050
wavelength, nm
sp
ec
tru
m, %
Lasing
Luminescence
Absorption
Lasing experiment
R=100%
R=95%
Lasing results
Lasing power for R=4.5%, W
0
0.5
1
1.52
2.5
3
3.5
0 20 40 60 80
Absorbed power, W
Best slope efficiency was 8%(for 4.5% transmission of output mirror)
Cooling
dT
dn
dT
dllas
æ~10 times
~ 5 times
severaltimes
Measurement of Lifetime
h
PD
exp fit to find τ
Broadening the set of investigated materials
Yb-doped ceramics:
Y2O3 - Japan (provided by Prof. Kaminsky)2% Yb
Sc2O3 - Japan (provided by Prof. Kaminsky)2% Yb
Lu2O3 - Japan (provided by Prof. Kaminsky)2% Yb
Y2O3 – Nizhny Novgorod, Russia5% Yb
Broadening the set of investigated materials
Yb-doped crystals:
YAG - Germany (provided by Moltech Gmbh)10% Yb
YAG - St.-Peterburg, Russia, (Vavilov Institute)10% Yb
YAG - Italy1% Yb
YAG - Erevan, Armenia (Laserayin Tekhnika CSC)1-20% Yb (5 samples)
Lifetime measurements
Lifetime
0
200
400
600
800
1000
1200
1400
1600
50 100 150 200 250 300 350
T, K
mks
YAG Ger
YAG Piter-Rus
YAG1 Erevan
YAG5 Erevan
YAG10 Erevan
YAG20 Erevan
YAG Italy
Lifetime measurements2
Lifetime
0
200
400
600
800
1000
1200
1400
1600
1800
2000
50 100 150 200 250 300 350
T, K
mks
Lu2O3 Jpn
Sc2O3 Jpn
Y2O3 Jpn
Y2O3 NN-Rus
Measurement of Luminiscence
h
Spectrometer
Luminescence spectrum measurements
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1000 1010 1020 1030 1040 1050
80K
110K
170K
200K
230K
260K
295K
Luminescence spectrum measurements
0
200
400
600
800
1000
1200
1400
1000 1010 1020 1030 1040 1050
80K
110K
140K
170K
200K
230K
260K
295K
Luminescence spectrum measurements
Luminescence normalized to room temperature
0
1
2
3
4
5
6
7
8
9
50 100 150 200 250 300 350
T,K
YAG Ger
YAG Piter-Rus
YAG1 Erevan
YAG5 Erevan
YAG10 Erevan
YAG20 Erevan
YAG20 Erevan
YAG Italy
Luminescence spectrum measurements
Luminescence normalized to room temperature
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
50 100 150 200 250 300 350
T,K
Lu2O3 Jpn
Sc2O3 Jpn
Y2O3 Jpn
Y2O3 NN-Rus
Emission cross section
Crosssection
0
2
4
6
8
10
12
14
16
50 100 150 200 250 300 350
T,K
YAG Ger
YAG Piter-Rus
YAG1 Erevan
YAG5 Erevan
YAG10 Erevan
YAG20 Erevan
YAG20 Erevan
YAG Italy
Emission cross section
Crosssection
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
50 100 150 200 250 300 350
T,K
Lu2O3 Jpn
Sc2O3 Jpn
Y2O3 Jpn
Y2O3 NN-Rus
Results• Ceramics manufacturing method was developed in Nizhny
Novgorod. Optical quality was demonstrated to be high enough to get 8% of slope efficiency
• Wide set of optical ceramics and crystals was tested and there were measured lifetime and cross section change while cooling down to 80K
• Wide spread in parameters behaviour observed for YAG crystals
• It was measured 3.5 increase in cross section for ocsidesceramics and decrease of lifetime from 1.1 ms down to 0.9 ms and it was observed similar behavior for SHS-MS manufactured ceramics
• Measured 3.2 increase of cross section and growth of lifetime from 1.1 ms up to 1.6 ms makes Yb:Lu2O3 ceramics quite promising for diode pumped high energy capacity systems
• Measured luminescence spectrums of ceramics showed about several nm spectrum widths at 80K which makes this ceramics promising for amplification of sub-picosecond pulses.