Air-Spaced
Etalons
Air-Spaced Etalons have appropriate grade fused
silica (UV-visible or IR) substrates.
Outside-face AR coatings and wedges on the
substrates prevent extraneous interference
patterns from forming. Spacers, optically
contacted to the substrates, determine the
parallelism of the mirrored surfaces and the
etalon’s free spectral range. Depending upon
the application, the spacers can be fused silica
or a low thermal expansion material such as
ZerodurÆ or ULE. |
|
| Plate Material |
Fused Silica |
| Spacer Material |
Fused Silica,
ZerodurÆ, or ULE |
| Flatness |
l/100 |
| Parallelism |
l/100 |
| Gap |
5m to 65mm |
| Clear Apertures |
2mm to 100mm |
| Outside Diameter |
Clear Aperture +
15% |
| Wavelengths |
157nm to 3m |
| Finesse |
Up to 100 |
| Coatings |
Standard and
Custom |
| Housing |
Acetal or
Aluminum |
|
|
|
|
Solid
Etalons
Solid Etalons typically have fused silica
substrates with the material grade (e.g.
UV-visible or IR) dependent on the spectral
region. The faces are ground, polished, and
figured typically to better than l/100 flatness with similar quality
parallelism between the faces. Dielectric (or,
rarely, metallic) coatings provide the
reflectivity necessary for the required finesse. |
|
| Material |
Fused Silica |
| Flatness |
l/100 |
| Parallelism |
l/100 |
| Clear Aperture |
2mm to 125mm |
| Diameters |
3mm to 150mm |
| Thickness |
50m to 20mm |
| Wavelengths |
157nm to 3m |
| Finesse |
Up to 50 |
| Coatings |
Standard and
Custom |
| Housing |
Acetal or
Aluminum |
|
|
|
|
MicroEtalons
Fiber optic communication requires extreme
miniaturization of optical components. It is for
applications such as DWDM (dense wavelength
division multiplexing), line narrowing, and
channel monitoring that TecOptics introduced its
new line of MicroEtalons. Newly developed
manufacturing techniques enable TecOptics to
supply large quantities of these miniature
air-spaced and solid etalons at low prices.
Air-spaced versions have dimensions as small as
4.5mm x 2mm x 3mm while solid MicroEtalon
cross-sections can be as small as 2mm. Finesse
values can be greater than 100. |
|
| Plate Material |
Fused Silica |
| Spacer Material |
ZerodurÆ or ULE |
| Flatness |
l/100 |
| Parallelism |
l/100 |
| Gap |
100m to 3mm |
| Clear Aperture |
2mm |
| Dimensions |
Down to 4.5mm x
2mm x 3mm |
| Finesse |
To 100 |
| Wavelengths |
All standard
fiber optic regions |
| Housing |
None |
|
|
|
|
Deposited
Etalons
To overcome the limit of the thinness of a solid
etalon yet retain its mechanical strength,
TecOptics offers its unique Deposited Etalons. On
one side of a precision substrate our
sophisticated coating plants sequentially deposit
a mirror coating, a silicon dioxide spacer, and
the other mirror coating. Deposited etalons'
applications include intracavity laser wavelength
tuning. |
|
| Substrate |
Fused Silica |
| Spacer Thickness |
2m to 25m |
| Clear Aperture |
2mm to 100mm |
| Wavelengths |
193nm to 2.5m |
| Finesse |
To 50 |
| Coatings |
Custom Design |
| Housing |
Acetal or
Aluminum |
* Note that for
any etalon it is not always possible to
attain all combinations of specifications
simultaneously.
|
| |
|
|
Ultra-Narrow
Tuned Etalon Filters
Frequently, standard interference filters are not
able to attain the resolution required for
precision applications. TecOptics Tuned Etalon
Filters fill this gap by adding an order of
magnitude or more of resolving power. A normal
narrow-band interference filter has a resolution
of approximately 10‰. By adding the Tuned Filter
to the interference filter, the resolution
improves to sub-angstrom levels. The basis of the
Tuned Filter is our ability to fabricate etalon
substrates and spacers with their thickness
precisely tuned so an integral number of
wavelengths matches the optical path length,
including the mirror coatings, of the light
inside the etalon. Their specifications are
similar to the Air-Spaced and Solid Etalons above
with the additional tight tolerance on spacer or
plate thickness to tune the desired wavelength. |
