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LGS(La3Ga5SiO14) Electro-Optical Q-Switch Crystal

22 May 2019

Description

LGS(La3Ga5SiO14 )is a multifunctional intraocular crystal that can be used as an electro-optic crystal after considering and studying the interaction between electro-optic effect and optical rotation in functional crystals. The LGS electro-optic Q switch passes light along the Z direction of the crystal and applies an electric field along the X direction, which can make full use of the lateral electro-optic effect of the crystal to realize the Q-switch function of the LGS crystal. The electro-optic Q-switch made by LGS is actually a new kind of rotation-electro-optical Q-switch. Because of the effect of optical rotation, it can be used as a practical switch and a good Q-modulation result can be obtained. LGS crystal widens the new direction of exploring and discovering new electro-optic crystals from optically active crystals.

Parameter

Material and Specifications

Point group 32
Airborne group P32I
specific resistance 4.0×1012Ω/cm-1
Thickness 0.13-0.5mm
Diameter 50mm
Length 90-100mm
Melting point 1470℃
Density 5.67g/cm3
Mohs hardness 5.5
Thermal expansion coefficient aa=16×10-6/K, ac=4×10-6/K
Photo damage threshold 670MV/cm2
Cell Parameters a=b=0.8162nm,c=0.5087nm
Dielectric constant ε11=18.27
ε33=55.26
Electro-optical coefficients γ11=2.3×10-12m/V
γ33=1.8×10-12m/V
Piezoelectric strain constant
(10-12)C/N
d11=6.3
d14=-5.4
Phase velocity,m/s 2750~2850
Electromechanical coupling coefficient, K[ %] 0.28~0.46
Solubility None
Coefficient of thermal expansion α11=5.15×10-6K-1
α33=3.65×10-6K-1

LGS crystal for Q-switch

Maximum operating frequency 50KHz  
Maximum output power 7.5W  
Pulse width 46ns  
Energy output -40℃ 155mJ  
Energy output +50℃ 163mJ  
Room temperature energy output 167mJ  
Electro-optic conversion efficiency 1.26%

Comparative properties of piezoelectric crystals

Propertie        
Quartz LGS Li2B4O7 LiTaO3
Electromechanical Coupling Factor K, %(BAW) 7 15.8 24 47
Frequency Spacing Δf, % 0.25 0.9 4 7
Q-Factor Q, ×103 100 50 10 2
Temperature Frequency Coefficient TFC,×10-6/℃ 0.5 1.6 6 4

SAW properties of langasite and Quartz

Properties   

Quartz  LGS
   
Density, g/cm³ 2.65 5.746
SAW Velocity Vef, m/s

(0°, 132.75°, 0°)

3157

(0°, 140°, 25°)

2756

Electromechanical coupling factor K2emc, %(SAW) 0.14 0.36
Second order temp. coef.α2, ×10-8/℃ -3.2 -6.8
Temp. Coef. TTO, ℃ 25 23
Dielectric Constant e 4.92 27
Power flow angle , ° 0 0.5

Dielectric, piezoelectric, elastic stiffness constants and their first order temperature coefficients of langasite crystal

Constant Relative Dielectric Constant Piezoelectric Constant (pC/N) Elastic Stiffness(1011 Pa)
ε11 ε33 d11 d14 c11 c12 c13 c14 C33 C44
Value 18.96 50.19 5.66 -5.48 1.898 1.058 1.022 0.144 2.626 0.535
First Order Temp. Coef.(10-6·K-1) 150 -760 329 -342 -66 204 -75 -335 -94 -63

Features

  • High damage threshold

  • Good optical rotation

  • Can withstand high and low temperature changes

  • Stable physical and chemical properties

  • High electromechanical coupling coefficient (3 times of quartz)

  • Low equivalent series resistance

Applications

  • electro-optic Q-switch

  • SAW device

  • BAW device

  • Sensor

  • High power high repetition rate all solid state laser

  • High and low temperature change laser

CONTACT DETAILS
Nanjing Crylink Photonics Co.,Ltd
No.3, Hengda Road, Economic and Technological Development Zone, Nanjing, China
No.200,Zhaoxian Road,Jiading District,Shanghai City
Nanjing
Jiangsu
210038
China
Tel: (86)025-68790684
Fax: (86)025-68790685
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