Plane parallels, etalons

Plane-parallels, wedge < 10’’

Diameter
Ø mm
Thickness
t mm
Wedge
Parallelism
Flatness
λ (633 nm)
Surface
imp.tol.
UV-FS
Article-No.
Stock
25 6.35 <10″ λ/10 5/3 x 0.040 S-01015
50 9.5 <10″ λ/10 5/3 x 0.040 S-01016

 available from stock

Etalons, wedge < 0.2’’

Fabry-Perot etalons are extremely narrow line width filters with a series of sharp transmission peaks, separated by the free spectral range (FSR). FSR depends only on the optical thickness of the etalons, whereas the finesse (F) is determined not only by the reflectivity of the coatings, but mainly by surface quality, parallelism, homogeneity of the substrate material and defect-free coatings. Solid etalons can be tuned by tilting and by temperature change.

If a minimum resolvable resolution Δλ is nee­ded, the reflectivity finesse FR can be calcula­ted with



The final finesse of the etalon is in most cases limited by the flatness finesse FF (flatness of λ/20 gives FF = 20) for beam diameter 20 mm. With thinner beams FF can grow to > 200. Pairs of etalons in series may be used to obtain ultra high resolution combined with a very long FSR. The resulting finesse of such a combination can be one order of magnitude higher.

Besides lower costs, solid etalons offer the following advantages over air spaced etalons for intracavity use:
higher transmission
 lower size
 harder coatings with
 higher damage threshold

Diam.
Ø mm
Thickn.
t mm
Wedge
Parallelism
Flatness
λ (633 nm)
Surface
imp.tol.
Suprasil 311
Article-No.
StockFSR
nm @ 633 nm
FSR
GHz
25 0.1 <0.2″ λ/20 in T 5/3 x 0.040 S-00209 1.38 1000
25 0.2 <0.2″ λ/20 in T 5/3 x 0.040 S-00185 0.69 500
25 0.3 <0.2″ λ/20 in T 5/3 x 0.040 S-00740   0.46 330
25 0.5 <0.2″ λ/20 in T 5/3 x 0.040 S-00353 0.28 200
25 1 <0.2″ λ/20 in T 5/3 x 0.040 S-01001   0.14 100
25 2 <0.2″ λ/20 in T 5/3 x 0.040 S-00932   0.069 50
25 3 <0.2″ λ/20 in T 5/3 x 0.040 S-00933   0.046 33
25 4 <0.2″ λ/20 in T 5/3 x 0.040 S-00029 0.034 25
25 5 <0.2″ λ/20 in T 5/3 x 0.040 S-00206   0.028 20
25 6.35 <0.2″ λ/20 5/3 x 0.040 S-00934   0.022 16
25 10 <0.2″ λ/20 5/3 x 0.040 S-00754 0.014 10
25 20 <0.2″ λ/20 5/3 x 0.040 S-00495   0.007 5

 available from stock