Er: YAG is a kind of excellent 2.94 um laser crystal, widely used in laser medical system and other fields. Er: YAG crystal laser is the most important material of 3nm laser, and the slope with high efficiency, can work at room temperature laser, laser wavelength is within the scope of the human eye safety band, etc. 2.94 mm Er: YAG laser has been widely used in medical field surgery, skin beauty, dental treatment.

Advantages of Er:YAG Crystals 
  • High slope efficiency 
  • Operate well at room temperature 
  • Operate in a relatively eye-safe wavelength range

Basic Properties:

Coefficient of Thermal Expansion

6.14 x 10-6 K-1

Crystal Structure


Thermal Diffusivity

0.041 cm2 s-2

Thermal Conductivity

11.2 W m-1 K-1

Specific Heat (Cp)

0.59 J g-1 K-1

Thermal Shock Resistant

800 W m-1

Refractive Index @ 632.8 nm


dn/dT (Thermal Coefficient of Refractive Index) @ 1064nm

7.8 10-6 K-1

Molecular Weight

593.7 g mol-1

Melting Point


MOHS Hardness



4.56 g cm-3

Tensile Strength

2 Gpa

Lattice Constant

a=12.013 Å

Laser Wavelength


Technical Parameters:

  • Orientation:[111] within 5°

  • Wavefront Distortion: ≤0.125λ/inch(@1064nm)

  • Extinction Ratio: ≥25 dB

  • Rod Sizes: Diameter:36mm, Length:50~120 mm (Upon request of customer)

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

  • 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% (@2940nm)