| Nd:YVO4 Crystal |
| Basic
Properties: |
|
| > Atomic density: |
~1.37 กม 1020 atoms/cm2 |
| > Crystal structure |
Zircon Tetragonal,space
group D4h
,a=b=7.12,c=6.29 |
| > Density |
4.22g/cm3 |
| > Mohs Hardness |
Glass-like,~5 |
| > Thermal expansion coefficients |
aa=4.43กม10-6/K ac=11.37กม10-6/K |
| > Thermal conductivity coefficients |
?C:5.23W/m/k; ?C:5.10W/m/K; |
Optical Properties(typically
for 1.1 atm% Nd:YVO4,a-cut crystals) |
| Lasing Wavelengths |
914nm,1064nm,1342nm |
| |
Positive uniaxial,no=na=nb,ne=nc |
| Crystal class |
no=1.9573, ne=2.1652,@1064nm |
| |
no=1.9721, ne=2.1858,@808nm |
| |
no=2.0210, ne=2.2560,@532nm |
| Sellmeier equation(for pure YVO4 crystals): |
| |
no2=3.77834+0.069736/(?2-0.04724)-0.0108133•?2 |
| |
ne2=4.59905+0.110534/(?2-0.04813)-0.0122676•?2 |
| Thermal optical coefficient: |
dna/dT=8.5กม10-6/K dnc/dT=3.0กม10-6/K |
| Stimulated emission cross -section |
25.0กม1019cm2,@1064nm |
| Fluorescent lifetime |
90µs,(about
50µsfor 2 atm% Nd doped) @808n |
| Absorption coefficient |
31.4cm-1@808nm |
| Absorption length |
0.32mm@808nm |
| Intrinsic loss |
less
0.1%cm-1@1064nm |
| Gain bandwidth |
0.96nm(257GHz) @1064nm |
| Polarized laser emission |
p
polarization;parallel to optic axis (c-axis) |
Diode pumped optical
to optical efficiency>60% |
Absorption Curves of Different Doping Nd:YVO4
Nd:YVO4shows high absorption coefficient at pumping wavelengths.Therefore,a
crystal short-in-length(e.g.1mm)is preferred,and more compact
lasers can be constructed by Using Nd:YVO4
than using Nd:YAG.Furthermore,it has a wide and smoothly-varied
bandwidth of absorption,so that it allows of less stringent
requirements of diode laser selection And wavelength control
as compared with Nd:YAG.Different doping levels Nd:YVO4
are shown showed as beside:
|
