Ho:Tm:YLF crystal is 2μm laser crystal with Tm ion sensitized. Conveniently pumped at 792nm, 2.05μm linearly polarized beam is output. Working mode is: First, Tm ion absorbs 792nm pump light energy, and transfers the energy to upper laser level of Ho ion by non-radiative transition, then Ho ion emits laser. The advantage of above working mode is simple structure and high efficiency of laser, so it contributes to miniaturization of laser. But the defect is that the crystal must bear higher heat loss, therefore it is unsuitable for high power laser output.

Advantages of Ho:Tm:YLF Crystals

Linearly polarized output beam

Little heat effect while laser

Conveniently LD pumped

Suit to miniature compact laser

Specifications

Dopant concentration

Tm:0～10at% Ho:0～3at%

Upon request of customer

Orientation

[100] or [001] within 5°

Wavefront distortion

≤0.25λ/25mm @632.8nm

Rod sizes

Diameter 3~9.5mm, Length 5~120mm
Upon request of customer (rod or slab)

Dimensional tolerances

Diameter:+0.00/-0.05mm，Length: ± 0.5mm

Barrel finish

Ground or polished

Parallelism

≤10"

Perpendicularity

≤5′

Flatness

≤ λ/10@632.8nm

Surface quality

10-5 (MIL-O-13830A)

Chamfer

0.15±0.05mm

AR coating reflectivity

≤0.25%

Optical and Spectral Properties

Laser transition

5I7 →5I8

Laser wavelength

2.05μm

Index of refraction

no=1.443 ne=1.464 @633nm

no=1.448 ne=1.470 @1064nm

Physical and Chemical Properties

Crystal Structure

Tetragonal

Melting Point

825℃

Moh Hardness

4-5

Density

3.95g/cm3

Thermal Conductivity

0.06W/cm/K

Young's Modulus

7.5×1011dynes cm-2

Tensile Strength

3.3×108dynes cm-2

Thermal Expansion Coefficient

[100] Direction:13×10-6/K

[001] Direction:8×10-6/K