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.