New Multiple Function Rare-Earth (Re) Calcium Oxyborate Crystals Ca4ReO(BO3)3 (Re = Y or Gd) and Re3+: Ca4ReO(BO3)3 (Re3+ = Nd3+ or Yb3+)
Ca4ReO(BO3)3 and Nd3+ (or Yb3+) doped Ca4ReO(BO3)3 crystal like Ca4YO(BO3)3 (YCOB), Ca4GdO(BO3)3 (GdCOB), Nd:Ca4YO(BO3)3 (Nd:YCOB),Nd:Ca4GdO(BO3)3 (Nd:GdCOB), Yb:Ca4YO(BO3)3 (Yb:YCOB) and Yb:Ca4GdO(BO3)3 (Yb:GdCOB) have gained tremendous interest for their excellent properties. These crystals possess large effective nonlinear coefficients, broad transparency range, high damage threshold, non-hygroscopicity and good mechanical properties.
Nd:YCOB, Nd:GdCOB, Yb:YCOB, Yb:GdCOB, YCOB and GdCOB crystals can be grown by the Czochralski method. The first four crystals can be used for infrared laser crystals and Type-I phase matching as self-frequency-doubling (SFD) crystal.
We can now supply both of the pure crystals and their doped ones.
PROPERTIES OF Nd:YCOB, Nd:GdCOB, Yb:YCOB
CRYSTAL DATA
Nd:YCOB Nd:GdCOB Yb:YCOB Yb:GdCOB YCOB GdCOB
Crystal Symmetry Monoclinic Monoclinic Monoclinic Monoclinic Monoclinic Monoclinic
Point Group[1] m m m m m m
Lattice Constants (nm)
a 0.8076(7) 0.8046 0.80937
b 1.6020(10) 1.5959 1.6013
c 0.3527(2) 0.3517 0.35579
b 101.23° 101.19° 101.27°
OPTICAL PROPERTIES
Optical transmission(nm) 236-2600 236-2600 200-2500 200-2500
Absorption Coefficient(cm-1)
812 nm 2.88
976.4nm 8.45
NONLINEAR OPTICAL PROPERTIES
Laser damage threshold
( GW/cm2 ) [2] ~1 ~1 ~1 ~1 ~1 ~1
Nonlinearity[1] pm/v ~1.1 ~1.3 ~1.1 ~1.3 ~1.1 ~1.3
THERMAL PROPERTIES
Melting point, ℃ 1510 1480 1510 1480 1510 1480
Thermal Expansion Coefficient (10-6/K )
X 11.6 12
Y 5.4 3.3
Z 5.9 6.6
Specific Heat(cal/g.K) 0.1589 0.1734
(330K)
LASER PROPERTIES
Pumped Threshold(mW)
(cw Ti:sapphire) 190[9] 90~288[11] 370[7]
Slope Efficiency(%) 44[9] 28~34[11] 28.6[7]
SFD PROPERTIES
Pumped Threshold (mW)
(cw Ti:sapphire) 23[9] 25[8]
(LD) 47[8]
Laser Output (mW)
(cw Ti:sapphire, 1W 40[9] 64[8]
pumping power)
(LD, 800 mW pumping power) 21[8]
(LD, 1250 mW pumping power) 114[12]
The Sellmeier equation for GdCOB crystal[1]: