Laser Materials YALO3 » Yttrium Orthoaluminate

Laser Materials YALO3 - Yttrium Orthoaluminate

General Information

SMC offers high quality Yttrium Orthoaluminate, also referred to as yttrium aluminum perovskite (YAP), doped with Tm, Nd, Pr, Er and Cr.

YAP´s hardness and thermal conductivity are similar to YAG, but exhibits a highly anisotropic thermal expansion coefficient and is birefringent. YAP is an orthorhombic negative biaxial crystal belonging to the D162h (Pnma) space group. Emission wavelengths are polarized, and emission and absorpton cross sections are dependant upon the crystalographic orientation. SMC (along with references [1] and [3] below), use the Pnma space group convenion for defining the crystalographic a, b, and c-axis lattice constants. Others (including reference [2]) use the Pbnm convention. In the table below, we related the two conventions thru their common lattice constants.

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Dopant Ion

Emission Wavelength 1.99 μm (E || a) 1.073 μm
  1.94 μm (E || c)  
Laser Transition 3F43H6 4F3/24I11/2
Pump Wavelength 795 nm lamp
Y3+ Site 1.96 x 1020 cm-3
Al3+Site (IV) 1.96 x 1020 cm-3
Al3+Site (VI) NA

Physical Properties

Coefficient of Thermal Expansion [3] 2.32 x 10-6 K-1 (a)
  8.08 x 10-6 K-1 (b)
  8.7 x 10-6 K-1 (c)
Thermal Diffusivity [3] 0.039 cm2 s-2 (a)
  0.045 cm2 s-2 (c)
Thermal Conductivity [3] 11.7 W m-1 K-1 (a)
  10.0 W m-1 K-1 (b)
  13.3 W m-1 K-1 (c)
Specific Heat (Cp) ¹ 0.557 J g-1 K-1
Refractive Index @ 632.8 nm 1.96(a)
dn/dT (Thermal Coefficient of Refractive Index) @ 1064nm [3] 7.7 10-6 K-1 (E || a)
  11.7 10-6 K-1 (E || b)
  8.3 10-6 K-1 (E || c)
Molecular Weight 163.89 g mol-1
Melting Point 1870°C
Density 5.35 g cm-3
MOHS Hardness 8.5
Crystal Structure Orthorhombic
Standard Orientation a-axis or c-axis
Y3+ Site Symmetry C1h

Lattice Constant

  (Pnma space group) (Pbnm space group)
5.330 Å a-axis b-axis
7.375 Å b-axis c-axis
5.180 Å c-axis a-axis


1) 1.94 micron and 1.99 micron emission of Tm:YAP is studied in Stoneman et. al.,

2) Emission and absorption properties of Nd:YAP are summarized in A. A. Kaminskii, "Laser Crystals: Their physics and properties", Second Edition, Springer-Verlag New York, 1990 Chapter 6.3; ISBN 0-387-09576-4

3) Thermo-optic properties of YAP and other laser host materials are studied in: R. L. Aggarwal, et. al., JOURNAL OF APPLIED PHYSICS 98, 103514 (2005)

Absorption Coefficient Chart

passive q-switch
passive q-switch

Data Sheet Downloads

pdf YALO3