Tm:YAP

Tm doped crystals embrace several attractive features that nominate them as the material of choice for solid-state laser sources with emission wavelength tunable around 2um. It was demonstrated that Tm:YAG laser can be tuned from 1.91 up to 2.15um. Similarly,Tm:YAP laser can tuning range from 1.85 to 2.03 um.The quasi-three level system of Tm:doped crystals requires appropriate pumping geometry and good heat extraction from the active media.On the other hand,Tm doped materials benefit from a long fluorescence life time,which is attractive for high-energy Q-Switched operation.Also,the efficient cross-relaxation with neighbouring Tm3+ ions produces two excitation photons in upper laser level for one absorbed pump photon.This makes the laser very efficient with quantum efficiency approaching two and reduces thermal loading.

Tm:YAG and Tm:YAP found their application in medical lasers, radars and atmospheric sensing.

Properties of Tm:YAP depends on crystals orientation.Crystals cut along the 'a' or 'b' axis are mostly used. 

Basic Properties:

Space group
D162h  (Pnma)
Lattice constants(Å)
a=5.307,b=7.355,c=5.176
Melting point()
1850±30
Thermal conductivity(W·cm-1·K-1)
0.11
Thermal expansion(10-6·K-1)
4.3//a,10.8//b,9.5//c
Density(g/cm-3)
5.35
Refractive index

1.943//a,1.952//b,1.929//c

 at 0.589 mm

Hardness(Mohs scale)
8.5-9