Solid etalons select narrow transmission bands through interference between partially reflective faces. UV-grade fused silica, coating reflectivity, thickness and wedge control determine bandwidth, free spectral range and transmitted wavefront quality.
Properties, applications and specifications
Solid etalons select narrow transmission bands or reduce source bandwidth. The reference construction uses UV-grade fused silica polished for low transmitted wavefront error, low wedge and high surface quality, with a partially reflective e-beam dielectric coating. Stated reflectivity spans 30% to 97%; thickness, operating wavelength and reflectivity are design variables.
Etalon coating, diameter, thickness and mechanical tolerances can be selected for the application.
Application:
Telecom
Medical Laser system
Industrial Q-Switch Laser system
Capabilities
|
|
Standard & Semi-custom
|
Additional Custom Options
|
|
Types
|
Solid
|
|
|
Materials
|
UV-grade fused silica
|
Infrasil, crystal quartz and Suprasil 1
|
|
Diameter
|
25.4 mm
|
Up to 100 mm
|
|
Thickness
|
0.25 to 15.0 mm
|
Minimum 10 μm
|
|
Coatings
|
Partially reflective dielectric,
from 30% to 97% reflectivity |
Partially reflective dielectric,
from 10% to 99% reflectivity |
|
Quality
|
Laser quality
|
See manufacturing tolerances below
|
Solid Etalon Manufacturing Capabilities
|
Surface Tolerances
|
Standard
|
Laser Quality
|
High Precision
|
|
Surface quality (scratch - dig)
|
40 - 20
|
10 - 5
|
5 - 2
|
|
Transmitted wavefront error
(P-V @ 633 nm before coating) |
λ/2
|
λ/10
|
λ/20
|
|
Effective finesse
|
|
0.22 to 13.4
|
Up to 50
|
|
Dimensional Tolerances
|
Standard
|
Precision
|
High Precision
|
|
Diameter (mm)
|
+0.000 / -0.250
|
+0.000 / -0.025
|
+0.000 / -0.005
|
|
Etalon thickness (mm)
|
± 0.250
|
± 0.150
|
± 0.010
|
|
Wedge
|
≤ 5 arc min
|
≤ 1 arc sec
|
≤ 0.5 arc sec
|
|
Clear aperture (%)
|
≥ 85%
|
≥ 90%
|
100%
|
