Solid Fused Silica Etalons

Fused Silica; 450-1700 nm; Finesse 0.6, 6, >30; FSR 20-4023 GHz, 0.5-2/cm; Thickness 0.025-6.743 mm; Uncoated or Coated; 2x4, 5x5, Dia. 25.4 mm; Clear Aperture Dia. 20 mm

LightMachinery’s broad range of solid Fused Silica (SiO2) etalons is manufactured using the company’s patented fluid jet polishing (FJP) technology – allowing the adjustment of the etalon’s shape and flatness to within a few nanometers. LightMachinery’s Fused Silica etalons are available uncoated in rectangular shapes with dimensions of 2 x 4 or 5 x 5 mm or with dielectric coatings in circular shapes and 25.4 mm diameter.

Uncoated 2 x 4 mm solid Fused Silica etalons are very small devices that our customers usually cement on one end to a holder. The small size is preferred for use inside small laser cavities. A dedicated 12.7 mm diameter aluminium mount designed to hold 2 x 4 mm etalons is available – its price includes cementing of the etalon to the mount at the supplier.

Uncoated 5 x 5mm solid Fused Silica etalons are slightly larger versions that are easier to manipulate with human hands. Again, a dedicated 25.4 mm diameter mount designed to hold 5 x 5 mm etalons is available – its price including cementing of the etalon to the mount at the supplier.

While uncoated, rectangular types feature a finesse of 0.6, circular 25.4 mm (1”) diameter solid Fused Silica etalons with dielectric coatings for higher finesse are available for five different wavelength ranges (450 to 650, 530 to 660, 700 to 850, 850 to 1100, 1450 to 1700 nm) and with finesse values of 6 or >30.

Etalons are optically transparent, flat components with very precisely parallel reflecting surfaces. For high performance (i.e. resolution), these components require very high-quality, flat and level surfaces with low roughness and extreme parallelism. Solid Fused Silica etalons are comparatively simple, robust, yet very parallel optical components with a wide variety of applications in spectroscopy and lasers.

Although solid etalons are generally coated to increase the finesse of the etalon, uncoated solid etalons – using only the 4% fresnel reflection to provide the etalon effect – are often used inside laser cavities since only low finesse is required to filter out unwanted laser wavelengths, and uncoated etalons are very damage resistant.

One major issue with solid etalons is their instability to temperature changes (both the index and the physical thickness of the etalon material change with temperature), which can be unacceptable in certain applications. In those cases, please refer to air spaced etalons that reduce this problem of temperature dependence by using air as the etalon medium. In certain applications though, the temperature dependence can also be a useful method for tuning the transmission peak position since it effectively changes the thickness of the etalon.

Sometimes you need something special – if you are looking for a customized solid Fused Silica etalon that exactly meets your specific requirements, please get in touch with the AMS Technologies etalon experts. Our supplier LightMachinery is extremely experienced with specifying, designing and manufacturing custom etalons using the company’s patented fluid jet polishing (FJP) technology. We are looking forward to discussing your customized etalon solution!

Fluid jet polishing (FJP) systems use a fine stream of slurry to accurately remove nanometers of material from an optical surface. Many years of refining this computer controlled polishing technology have enabled LightMachinery to use FJP for the adjustment of the shape and flatness of optical components such as etalon mirrors to within a few nanometers as well as the production of very thin components such as wafers and thin etalons that are impossible to accurately polish using conventional technology.

Key Features:

• Etalon Material: Fused Silica
• Wavelength Range: 450 to 1700 nm
• Finesse: 0.6, 6, >30
• Free Spectral Range, FSR: 20 to 4023 GHz, 0.5/cm to 2/cm
• Coating: Uncoated or Dielectric Coating
• Rectangular Types: 2 x 4, 5 x 5 mm
• Dedicated 12.7 or 25.4 mm Diameter Aluminium Mounts Available for Rectangular Types – Price Includes Cementing of the Etalon to the Mount at the Supplier
• Circular Types: Diameter 25.4 mm (1”)
• Clear Aperture: 85% of Outside Dimension (Diameter 20 mm for Circular Types)
• Matched Surface Figure: λ/100
• Surface Quality: 10/5 or Better
• Wedge: 0.1 arcsec Typical

Applications: Spectroscopy; Lasers; Interferometers; Wavelength Measurement; Fine-structural Investigation of Spectral Lines