Senior sales engineer
Arminas Butkus +370 5 219 4884
Tm, Ho:KYW crystals
Please fill out this field
Please fill out this field
Please fill out this field
Please fill out this field
Please fill out this field

One of our 4Lasers team members will contact you as soon as possible.

Go back to homepage

Tm, Ho:KYW crystals

Main features


  • Large and broad polarized absorption and emission bands
  • Efficient energy transfer Tm3+ → Ho3+
  • High dopant concentration with low concentration-quenching
  • Custom crystals available upon request


Application examples


  • 2 μm lasers for remote sensing (LIDAR technology), metrology and medical applications
  • Pump source of mid-IR optical parametric oscillators (OPOs)
Request custom
  • Description
  • Properties
  • Absorption and emission curves
  • Standard specifications

Ho3+ ions are characterized by higher emission cross-sections and longer upper laser level lifetimes compared to their Tm3+ counterparts. These features are desirable for a low-threshold and efficient laser operation. Ho3+ does not possess any strong absorption lines that are well matched to the outputs of commercially available laser diodes, therefore co-doping of Ho3+ with Tm3+ is chosen for an efficient operation across the 2 μm region through the energy transfer route from Tm3+ to Ho3+. Tm, Ho:KYW crystals are characterized by large and broad polarized absorption and emission bands, efficient energy transfer from Tm3+ to Ho3+.

Spectroscopic and thermo-mechanical properties
Absorption peak wavelength 802 nm
Absorption cross-section at peak 7,6 × 10-20 cm2
Absorption bandwidth at peak wavelength ~4 nm
Laser wavelength 2060 nm
Lifetime of 5I7 energy level 1,8 ms
Emission cross-section @2056 nm 4,7×10-20 cm2
Refractive index @1040nm ng=2,05, nm=2,01, np=1,97
Crystal structure Monoclinic
Density 6,5 g/cm3
Mohs hardness 4-5
Thermal conductivity ~3,3 Wm-1K-1
dn/dT dnm/dT= -9,2 × 10-6 K-1
Thermal expansion coefficient αp= 1,83 × 10-6 K-1, αm=10,29×10-6 K-1, αg= 15,94 × 10-6 K-1
Typical doping level 5 at.% [Tm]
0,5 at.% [Ho]

Tm, Ho:KYW crystals
Orientation Ng-cut
Clear aperture >90%
Face dimensions tolerance +0,0/-0,1 mm
Length tolerance ±0,1 mm
Parallelism error <10 arcsec
Perpendicularity error <10 arcmin
Protective chamfers <0,1 mm at 45˚
Surface quality 10-5 S-D
Surface flatness <λ/10@632,8 nm
Coatings AR(R<0,5%)@802 nm + AR(R<0,2%)@2000-2100 on both faces
LIDT >10 J/cm2@2060 nm, 10 ns
Mount Unmounted
Order your item
Face dimensions Length End faces Doping Coatings SKU PRICE QUANTITY
3x3 mm
2 mm
Right-angle cut
Tm 5%, Ho 0,5%
AR/AR@802 nm+2000-2100 nm
3x3 mm
2 mm
Brewster-angle cut
Tm 5%, Ho 0,5%