Er:YAG Laser Crystal

Erbium Substituted : Yttrium Aluminium Garnet

Er:YAG Lasers powered by Er:YAG (erbium substituted: yttrium aluminium garnet), operating at 2.94 microns, crystals couple well into water and body fluids. This is especially useful for applications in the fields of laser medicine and dentistry. The output of Er:YAG enables the painless monitoring of blood sugar levels, while safely reducing the risk for infection. It is also effective for laser treatment of soft tissue, such as cosmetic resurfacing. It is equally useful for treating hard tissue such as tooth enamel.

Er:YAG enjoys an advantage over other laser crystals in the 2.94 micron range in that it employs YAG as the host crystal. The physical, thermal and optical properties of YAG are widely known and well understood. Laser designers and operators can apply their depth of experience with Nd:YAG laser systems to achieve superior performance from 2.94 micron laser systems using Er:YAG.

Proprietary technology allows the production of Er:YAG crystals of excellent optical quality, low scattering losses; having higher efficiency, higher output and higher damage threshold. This technology allows the material to overcome the poor efficiency once associated with the use of 2.94 micron wavelength laser material.

Er:YAG laser crystals in sizes from 3 mm to 10 mm diameter, with lengths up to 150 mm long. Call upon our depth of experience in research, crystal growth and laser rod fabrication. Roditi will work with you to produce laser crystals that meet the exact specifications for superior performance of your 2.94 micron ER:YAG laser system.

Applications

Designed for 2.94 µm output wavelength Er:YAG is an excellent choice for Medical Laser Systems.
Dental Laser Systems.

Optical and Laser Properties

Laser Action	4 Level Laser	Lower Level	⁴I_13/2
Output Wavelength	2.94 µm at 20°C	Upper Level Lifetime	100 µsec
Emission Cross Section	Σ = 2.1 x 10^-20 cm²	Refractive Index	1.838 at 632.8 nm
Upper Laser Level	⁴I_11/2	Chemical Formula	Y_{(3 -x)}Al₅O₁₂:Er_(x) (50% Er)

Absorption Bands

0.80µm (⁴I_15/2 - ⁴I_9/2)	0.52µm (⁴I_15/2 - ²H_11/2)	0.44µm (⁴I_15/2- ⁴F_3/2)
0.65µm (⁴I_15/2- ⁴F_9/2)	0.49µm (⁴I_15/2- ⁴F_7/2)	0.41µm (⁴I_15/2- ²H_9/2)
0.54µm (⁴I_15/2- ⁴S_3/2)	0.45µm (⁴I_15/2- ⁴F_5/2)	0.38µm (⁴I_15/2- ⁴G_11/2)

Er:YAG Laser Rod Standard Fabrication Specifications

Feature	Standard	Special Order
Crystal Orientation	<111> within 5°	Available
Diameter	3 mm to 8 mm	Available
Daimeter Tolerance	+0.0 mm/- 0.05 mm	Available
Length (plano/plano)	30 mm to 150 mm	Available
Length Tolerance	± 0.75 mm	± 0.50 mm
Perpendicularity of End Faces (plano/plano)	5 arc-minutes	2 arc-minutes
Parallelism of End Faces (plano/plano)	10 arc-seconds
Flatness	0.1 wave maximum	0.10 wave maximum
(plano/plano)	over 90% of aperture	over full aperture
Surface Finish at 5X	20-10 (scratch & dig)	10-5 (scratch & dig)
Barrel Finish	400 grit	Polished approx. 80-50
End Face Bevel	0.075 mm to 0.12 mm at 45° angle
Chips	No chips allowed on end face of rod; chip having maximum length of 0.3 mm permitted to lie in the area of bevel and barrel surfaces.
End Configurations	plano/plano, plano/wedge, wedge/wedge or Brewster cut. Plano ends can be finished flat, concave or convex
Coatings	Standard coating is AR at 2.94 µm with R<0.25% each face. Other coatings available.