Tm:YLF has a large emission cross section of nearly 2 μm, and the fluoride has moderate hardness and thermal conductivity and is commonly used as a laser substrate. Under the same pumping conditions, the thermal lensing effect of YLF is much weaker than that of YAP. therefore, Tm:YLF is also widely used in the medical field. The 2 μm laser has important applications in high-precision surgery, mainly because water molecules absorb light in this band, thus reducing its penetration into the body. The cutting accuracy is on the order of microns, resulting in minimal damage to the nearby area.
2000nm Laser (Tm:YLF)
- M1 and M2 are endoscopes
- L1 and L2 are cylindrical lenses
L1 is a cylindrical lens with a focal length of 150 mm and L2 is a cylindrical lens with a focal length of 100 mm. They act as focal points.
- λ/2 is 1/2 glass at 792 nm
The pump wavelength is 791.5 nm, and the absorption is enhanced by rotational polarization through 1/2 glass parallel to the YLF.
- Tm:YLF crystals
Tm:YLF has a large emission cross section at 2 μ m and is a natural birefringent crystal, which can achieve linear polarization output. Most importantly, it has a negative thermal dispersion coefficient, which can compensate the positive lensing effect caused by thermally induced end-face deformation and mitigate the thermal lensing effect.