Opto Sigma

•  Provides a 5% reflected sample of the entire beam 
• Highly efficient Anti-Reflection coating on the second surface to eliminate ghosts
• Available in four standard diameters
• Wedged second surface also available for highly demanding applications
• Surfaces finished to λ/10 flatness
• Standard diameters from 25.4 to 50.8mm

About 5% of a beam incident at 45 degrees is reflected from one surface of these BK7 beam samplers. The faces are parallel to within 5arcsec with a highly effective Anti-Reflection coating on the second surface. This coating eliminates virtually all ghost image problems. The 5% reflected beam is useful for diagnostic sampling or monitoring of the optical beam.

• Four wide wavelength regions for complete coverage of visible and near-IR
• Cube faces AR coated to prevent ghosts
• Standard cubes from 5 to 30mm
• All coatings are multilayer dielectric
• 5mm beamsplitter cubes available for fiber optic applications

These superior broadband beamsplitters use multilayer dielectric films to produce approximately equal reflectance and transmittance over a broad range of wavelengths. Three different wavelength ranges are offered covering the visible and near infra-red spectrum.

The beamsplitting film is deposited on the hypotenuse face of a precision BK7 prism whose faces are λ/4 and the prism is cemented to an identical prism to form a cube which is parallel sided within 5arcmin. The four outer faces are all Anti-Reflection (AR) coated.

Four sizes are offered including a very small 5mm cube which is ideal for fiber optic applications and other uses in which small configurations are required. Standard sizes are 5,10,15 and 20mm. Larger sizes are available on request.

• Thin film polarizers for broadband use
• Three convenient wavebands cover most applications
• Laser quality and performance
• 100:1 Extinction ratio

These thin film cube beamsplitters combine the excellent characteristics of the laser polarizing beamsplitters previously described with the advantage of broadband application. The polarizing film is fully protected within the cube making them durable and convenient to use. Three wavebands have been chosen to cover most general applications: 450-680 covers the visible spectrum and a wide selection of laser wavelengths, 650-850 covers most visible range diode lasers and 1300-1600 covers most telecommunications band diode lasers. Although these polarizers will work well over the entire broadband specified they are manufactured to laser performance standards.

• Designed to separate YAG laser outputs as a function of wavelength

• Three standard designs provide alternate transmission/reflection of the harmonics
• Measured laser damage threshold guidelines
• Provided on Grade A BK7 substrates
• Surfaces finished to λ/10 flatness
•   Available for 532/1064 and 355/1064

These are dichroic (i.e., color dependent) beamsplitters which separate the YAG fundamental from its second harmonic. Three configurations are offered. One reflects the fundamental and the second reflects the 532nm harmonic and the third reflects the 355nm harmonic. They are available in four sizes 25.4mm, 30mm, 50mm and 50.8mm diameter.

• Thin film polarizers optimized for use at popular laser wavelengths
• Transmittance p-polarization < 97%
• High Power Polarizing Cube Beamsplitters have greater durability than standard laser polarizing cube beamsplitters
• Multilayer high efficiency narrowband Anti-Reflection coatings on all faces

• Available with highly parallel or wedged faces to reduce ghosts
• Polished both sides to λ/10
• Coating optimized for low loss
• Available with Ultra-Violet grade fused silica and BK7 substrates
• Standard diameters from 25.4 to 50.8mm

These superior beamsplitters are multilayer dielectric coatings on a BK7 or synthetic fused silica substrate. The beamsplitter substrate is polished on both sides to a flatness of λ/10. Substrates can be either precisely parallel to 5arcsec or wedged with a 1 degree angle. The wedge angle eliminates ghost images by bending the beam out of the direction of the principal beam.

Note that when used as intended at 45 degrees these beamsplitters present a smaller cross section to the beam. (The 30mm diameter, 3mm thick size presents a 20mm cross section and the 50mm diameter, 5mm thick size presents a 32mm cross section). The coatings provide approximately equal reflected and transmitted beams with very little absorption loss. However the, p- and s-components are quite different (typically Rp=35% and Rs=65%). Several different coatings are offered from the Ultra-Violet through the visible to the near IR.

• Thin film polarizers optimized for use at popular laser wavelengths
• Transmitted extinction ratio of better than 2.5x10-3
• Reflected extinction ratio of better than 2x10-2
• Polarizing film mounted on the internal face of a cube beamsplitter
• Multilayer high efficiency narrowband Anti-Reflection coatings on all faces

These are thin film polarizers constructed as a cube. Thin film polarizers utilize the polarization which occurs on reflection from a plane surface. By combining a large number of such surfaces in a stack it is possible to obtain useful extinction ratios. The s-polarization is more than 99% reflected while the p-polarization can be suppressed in the reflected beam and become 95% transmitted. Thin film polarizers can be optimized for a particular wavelength to give superior performance for laser applications.

• Metal-dielectric hybrid coatings
• Broadband neutrality
• Low polarization effect
• Low absorption
• Standard cubes from 5 to 20mm

These popular cube beamsplitters use a special combination of metallic and dielectric coatings on the internal splitting face to produce an even split in intensity with minimal polarization and minimal absorption. They make excellent beamsplitters for all but the most demanding applications. Beamsplitting is almost neutral over a broad range of wavelengths. Four wavelength ranges are offered. Two are broadband (400-700 & 600-900) and two are ultra-broadband (400-1000 & 800-1600). The reflected and transmitted beams each contain about 45% of the incoming intensity with only 10% absorbed. Also the s- and p- polarization components are within ±10%.

These beamsplitters are made from optical grade BK7. The faces are polished flat to λ/4 and two like prisms are cemented together to form a cube. Both pairs of sides are parallel to within 5arcmin. The four outer faces are broadband Anti-Reflection coated.

Four standard sizes are offered: 5,10,15 and 20mm. Larger sizes are available on request.

• All four faces AR coated and flat to λ/4
• Inexpensive, yet effective for many beamsplitting requirements
• Both transmission/reflection typically 25% - with 50% absorption
• Standard cubes from 10 to 30mm

For white light applications where even intensity splitting is required over a broad wavelength region these simple cubes, with metallic coatings, make an ideal beamsplitter.

• The thin metallic film acts as broadband partially transmitting mirror
• Substrates polished both sides to λ/10
• Wedged substrates (for ghost suppression) are also available as standard
• Standard diameters from 25.4 to 100mm

These beamsplitters provide a highly neutral reflectivity over the visible spectrum and are most useful for broadband or tunable wavelength applications. A separate coating, optimized for use at the near-IR diode wavelengths, is available.

• All-dielectric coatings optimized to be insensitive to polarization at design wavelengths
• BK7 cube material - polished to λ/4
• Available in a range of laser wavelengths
• Highest performance - negligible absorption
• 5mm beamsplitter cubes available for fiber optic applications
• Standard cubes from 5 to 20mm

The all-dielectric coatings for these cube beamsplitters are largely insensitive to the polarization state of the incoming beam. The coatings have been designed to hold both the s- and p-polarization components to the same ratio of reflection-to-transmission over a specific laser wavelength region. The graph shows a typical reflectivity curve for the 633nm wavelength. At all the design wavelengths the s-reflectance equals the p-reflectance within ±3%, while both the reflectance and the transmittance equal 50% within ±5%.

Non-polarizing beamsplitters are available for other wavelength regions. Please call.

These beamsplitters are made from optical grade BK7. The faces are all polished flat to λ/4 and two like prisms are cemented to form a cube. Both pairs of sides are parallel to within 5arcmin. The four outer faces are all Anti-Reflection coated.

Four standard sizes are offered: 5,10,15 and 20mm. Larger sizes are available on request.

• No change in optical path length between reflected and transmitted light
• Pellicles eliminate second surface reflections
• Available in 1, 2 and 4 inch clear apertures
• Thickness uniformity is held to 2 waves per inch

Pellicles are thin nitrocellulose films which are stretched over a metal frame. Since they are less than 2 microns thick the reflected beams from both surfaces are essentially superimposed upon each other. Uncoated pellicles reflect 10% of the incident light when used at 45 degrees, thus providing a useful, low-intensity side beam. These pellicles can also be coated with various thin films in order to change the reflectivity and provide for a range of useful splitting ratios.

The pellicles are offered in three sizes 1 inch, 2 inch, 4 inch clear aperture.