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Neodymium
Doped Yttrium Vanadate (Nd:YVO4)As one of the most efficient and
excellent laser crystals, Neodymium doped Yttrium vanadate (or
orthovanadate, Nd:YVO4 ) is used most suitably to build stable, cost
effective and powerful diode-pumped solid-state IR, green lasers, due
to its obvious advantages: low threshold, large stimulated emission
cross-section at lasing wavelength, high slope efficiency, large
absorption coefficient and wide absorption peak at pump wavelength,
low intrinsic optical loss, high laser induced damage threshold,
strong polarized output and good physical, optical and mechanical
properties as well.
Our
improved growth technologies ensure Beijing Gospel OptoTech Co. (GOT)
as a stable supplier of Nd:YVO4 crystals (as large as f (30〜40)x(40〜42)mm3
ingots) with consistent high optical quality, unbeatable price and
prompt delivery, for R&D, industrial and commercial users. GOT's
strong production capability, for example, about 3,000〜
5,000 pieces of the laser-grade polished wafers with the most standard
dimensions (3x3x0.5, 3x3x1 and 3x3x2 mm3, A-cut) used in miniature
DPSS lasers per month, makes us a reliable supplier for OEM customers.
Please refer to the following background data and technical
information to assist you in its use.
Basic Properties
◆Density
3.01 g/cm3
◆Atomic
Density
〜1.37x1020
atoms/cm3
◆Crystal
Structure
Zircon
Tetragonal,space group Dth
◆Lattice
Parameters
a = 7.12A,
b = 7.12 A, c = 6.29 A
◆Melting
Point
〜1700° C
◆Mohs
Hardness
〜 5
(Glass-like)
◆Thermal
Expansion Coefficient
α
a=4.43x10-6/° C, α c=11.37x10-6/° C
◆Thermal
Conductivity Coefficient
‖C:0.0523 Wcm/° C, ⊥C:0.0510
Wcm/° C
(typically
for A-cut 1 atm% Nd:doped-YVO4 crystals)
Optical
and Laser Properties
◆Lasing
Wavelength
1064 m m, 1.342 mm
◆Crystal
Class
positive uniaxial, no=na=nb, ne=nc
no=1.9573, ne=2.1652 @1.064 mm
no=1.9721, ne=2.1858 @0.808 mm
no=2.0210, ne=2.2560 @0.532 mm
◆Sellmeier
Equation (pure YVO4 crystal)
no2 = 3.77834+0.069736/(λ2-0.04724)-0.0108133λ2
ne2 = 4.59905+0.110534/(λ2-0.04813)-0.0122676λ2
◆Thermal
Optical Coefficient
dna/dT = 8.5x10-6/° C, dnc/dT = 3.0x10-6/° C
◆Absorption
Coefficient
31.4 cm-1
@0.808 mm
◆Absorption
Length
0.32 mm @0.808 mm
◆Intrinsic
Loss
0.02 cm-1 @1.064 mm
◆Gain
Bandwidth
0.96 nm (257 GHz) @ 1.064 m m
◆Fluorescence
Lifetime
90m s @0.808 mm (about 50m s for 2 atm% Nd doped)
◆Polarized
Laser Emission
p polarization, parallel to optic axis (C-axis)
◆Stimulated
Emission Cross-Section
2.5x10-18 cm2 @1.064 mm
◆Diode
Pumped Optical to Optical Efficiency
>60%
DPSS Lasers - the Main
Application of Nd:YVO4
CrystalsComparing
with Nd:YAG, Nd:YVO4 has higher absorption coefficient at pumping
wavelengths, it means that Nd:YVO4 with shorter lengths (e.g. 1mm) can
be constructed more compact lasers. The stimulated emission
cross-section at 1.064 m m of A-cut Nd:YVO4 is about 4 times that of
the Nd:YAG. Moreover, when the laser cavity is properly designed, the
slope efficiency of Nd:YVO4 can be very high because of its high pump
quantum efficiency (h p). Furthermore, the wider absorption bandwidth
(801-820 nm) permits a less sensitivity of diode laser selection, and
pump wavelength drift due to the variations of temperature or aging of
diode. These features guarantee Nd:YVO4 as one kind of laser host
which is most suitable to construct more compact and significantly
more efficient diode-pumped solid-state (DPSS) lasers. Over 350 mW
1.064 m m output was obtained while a 1 mm length, A-cut Nd:YVO4 was
pumped by one 1 W diode laser.
In compact
cavity design of Nd:YVO4+KTP, high power green output can be generated
in a diode-pumped Nd:YVO4 laser. When pumped by 1 W diode laser, more
than 150 mW TEM00 532 nm output was reached with a 3x3x1 mm3 Nd:YVO4
and a 3x3x5 mm3 intracavity KTP. Fig. 1 shows the scheme for compact
design of diode-pumped green laser (Nd:YVO4 + KTP).
Fig. 1 Scheme for compact design of DPSS green laser
Because of
its very large stimulated emission cross section at 1.34 m m (18 times
larger than that of Nd:YAG), Nd:YVO4 is efficient and has good
performance in diode-pumped 1.34 m m laser. When 1 mm long Nd:YVO4
crystal pumped by an 850 mW diode laser at 808 nm, 50 mW output at
1.34 mm has been observed, compared to 34 mW from 2 mm long Nd:YAG.
Standard Specs. of Nd:YVO4 Crystals
◆Nd
Doping Level
0.5, 1, 2, 3 ±0.2 atm%
◆
Standard Dimension :
1) 3x3x0.1, 0.2 mm (laser polished only)
2) 3x3x0.5, 1, 2 mm (laser polished or coated)
3) 3x3x4, 5, 8, 10, 12, 15, 20 mm (as item 2)
4) other apertures (such as 2x2, 4x4 mm, 5x5 mm,
etc.)
◆
Aperture Tolerance
+0.1/-0.0 mm
◆
Wavefront Distortion
< l /8 @633 nm
◆
Scattering Sites
invisible, probed with
a He-Ne laser
◆
Orientation
A-axis or C-axis cut, ±0.2°
◆End
Surfaces Configuration
1) plano/plano ends
2) plano/Brewster-cut ends
3) Brewster-cut/Brewster-cut end
4) Other angle-wedge ends
◆
Surface Finish
10/5 scratch/dig as per MIL-O-13830A
◆
Flatness
λ /10 @633 nm
◆
Parallelism
< 10 arc seconds
◆
Perpendicularity
< 5 arc minutes
◆
Clear Aperture
> Central 90%
◆
Typical Coatings
I) Both ends AR @1064 nm (R1064nm<0.1%);
II) S1 - HR @1064 nm & HT @808 nm
(R1064nm>99.9% & T808nm>97%);
S2 - AR @1064 nm (R1064nm<0.1%);
III) S1 - HR @1064&532 nm & HT @808 nm
(R1064nm>99.9%, R532nm>99.5%,T808nm>97%)
S2 - AR @1064 nm & 532 nm
(R1064nm<0.1% & R532nm<0.2%);
IV) Other kinds of AR, HR coating upon request.
Special Notes for Nd:YVO4 Crystals
・ The large side surfaces, such as 3x15, 20mm, can be
polished to lambda/8 (flatness) and 10/5 scratch/dig (surface quality)
for the Nd:YVO4 slabs (with plano/plano ends, plano/Brewster-cut ends
or both Brewster-cut ends).
・ To meet the rapid development of DPSS green laser
market, GOT prepares large quantities of KTP as well as Nd:YVO4 with
standard dimensions (3x3x0.5, 1 or 2 mm3, etc.) with GOT''s coating
type I, II in stock, and can deliver goods off-shelf.
・ Free Nd:YVO4 samples are available from GOT for the
purpose of long term technical and business cooperation, and the
evaluation of OEM customers as well.
・ Our engineers will provide specific designs and the
latest technical information for KTP.
・ Special large discounts for industrial customers!
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