Solid Silicon Etalons
Product information "Solid Silicon Etalons"
Silicon; 1.2-6.3 µm; Finesse ~2.5, Dependent on Wavelength; FSR ~0.5-10 GHz; Thickness 0.025-83.110 mm; Uncoated; 8x8, Dia. 25.4 mm; Clear Aperture Dia. 5, 12.7 mm
LightMachinery’s series of solid Silicon etalons are high-index components for IR wavelengths, 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.
These etalons are available in two standard sizes: 8 x 8 mm thin solid Silicon etalons with thicknesses of 0.025 to 0.831 mm and 25.4 mm (1”) diameter thick solid Silicon etalons with lengths of 4.155 to 83.110. A dedicated 25.4 mm diameter aluminium mount designed to hold 8 x 8 mm etalons is available – its price includes cementing of the etalon to the mount at the supplier.
Solid Silicon etalons are interesting because the high index of Silicon (3.4 depending on wavelength) creates a reasonably high finesse without any coatings. The temperature sensitivity of Silicon can also be useful (or problematic). These etalons are often used to monitor the wavelengths of long-wavelength lasers.
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 Silicon etalons are comparatively simple, robust, yet very parallel optical components with a wide variety of applications in lasers and spectroscopy.
Although solid etalons are generally coated to increase the finesse of the etalon, uncoated solid etalons like this series – 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 Silicon 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: Silicon
- Wavelength Range: 1.2 to 6.3 µm (Infrared, IR)
- Finesse: ~2.5, Dependent on Wavelength
- Free Spectral Range, FSR: ~0.5 to 10 GHz
- Uncoated
- Two Standard Sizes: 8 x 8 mm, Diameter 25.4 mm (1")
- Thickness: 0.025 to 83.110 mm
- Dedicated 25.4 mm (1”) Diameter Aluminium Mount Available for 8 x 8 mm Types – Price Includes Cementing of the Etalon to the Mount at the Supplier
- Clear Aperture: Diameter 5, 12.7 mm
- Surface Figure: λ/20
- Surface Quality: 40/20 or Better
- Wedge: <0.5 arcsec – If Coating is Required, Wedge Can Be Reduced and Finesse Can Be Increased
Applications: Wavelength Monitoring of Long-wavelength Lasers; Spectroscopy; Interferometers; Wavelength Measurement; Fine-structural Investigation of Spectral Lines