Opto Sigma

• Two versions available for calibrated visible (425-675nm) and near-IR coverage
• Supplied in three popular diameters - 25mm, 30mm and 50mm
• Transmittances available from 0.01% to 90%
• Mounted version has a convenient metal ring
• Unmounted visible and YAG versions also available

These are absorbing glass type ND filters. Neutral density filters are very useful in a variety of applications where a precise and known beam attenuation is needed. Filters may be stacked for additive attenuation. These filters are mounted in metal rings which provide mounting convenience. The outside diameters of the mounting rings are 25mm, 30mm and 50mm. The clear apertures of the filters are 17mm, 25mm and 45mm respectively. As well as a standard line, a series is offered for use with low power YAG lasers. These are optimized to have the precisely stated densities at 1064nm. These YAG ND Filters are for low power applications only. We do not specify or guarantee a damage threshold.

• Made from the finest quality color glasses
• All are available in standard 3mm thicknesses
• Ultra-Violet and IR cut-off filters help to protect polymer and organic devices
• Heat absorbing filters reduce thermal strain on downstream optics

We offer a wide selection of colored glass filters. These are made from high quality optical colored glass. They are 2 inches square and unmounted.

• These multilayer thin-film dielectric coatings provide precision color control
• Will not fade or degrade with time - unlike organic or gelatin filters
• Available in both additive and subtractive configurations

These color filters are made for color process work where color consistency and stability are important. The multilayer dielectric coatings are hard and durable and will not fade or degrade with time as other filter materials often do.

The subtractive dichroic color process filters are useful for separating colors prior to printing or other processing or any other time one wishes to remove a spectral region from an imaging system. The additive dichroic filters are often used in three-color projection systems where the original images are produced by RGB phosphors. These filters have a glass substrate and they are not mounted.

• Ground Glass available in three grades of diffusion for all applications
• Surfaces are ground from the polished state for high uniformity
• Opal glass diffusers provide nearly complete diffusion for demanding applications
• Available in two popular diameters: 30mm and 50mm

Two types of diffuser are offered: ground glass and opal glass. Ground glass is acceptable for most applications. Six grades of grind are offered representing fine, medium, and coarse scattering surfaces. A finer grind provides a higher transmittance. Opal glass provides excellent diffusion at the expense of a very high loss factor. The rear surfaces of all our diffusers are polished.

These convenient filter sets offer the advantage of spectral or intensity modification to suit the particular circumstances. Often it is necessary to change the characteristics of a beam of light and it is useful to have a selection of calibrated filters on hand for this purpose. Our filter sets are supplied in a convenient storage binder together with their actual spectrophotometer traces. This way you are able to select filters for use singly or in combination to modify the incident light to suit your purpose.

We offer 6 different filter sets. Short-pass and long-pass filters can be combined to restrict the spectral region of interest. Our sets cover the spectrum using 13 filters at 50nm intervals from 400 to 1000nm. Two narrow band interference filter sets permit the isolation of very narrow spectral regions. We offer a 40nm halfwidth set and a 10nm halfwidth set. In each case there are 13 filters covering the spectrum from 400 to 1000nm. Attenuation filter sets are provided for the visible spectrum and for the 1064nm YAG line. The visible range set is made from neutral density glass while the YAG set is made from a range of different glasses calibrated to provide the exact required attenuation at the YAG wavelength. Nine filters cover transmittance values in 10% intervals from 10% to 90%.

The filters supplied in the narrowband and attenuation sets are all mounted in inch diameter (25mm) metal rings for convenience of mounting and handling. They are marked on the edges with the appropriate wavelength or transmittance.

• Actuating lever allows diaphragms to be easily and precisely adjusted
• Double blade versions allow the diaphragm to be completely closed
• Leaves are made from blackened, tempered steel
• Outer casing designed for push fit mounting

These iris diaphragms are made from tempered steel leaves mounted in a metal ring. They are fitted with an actuating lever. Each iris has a smooth and continuous operating range. If it is required that the iris can be closed down to zero aperture then it is important to use the dual blade type. These irises have a plain outer casing which is normally mounted in a housing with a slight push fit.

Laser line filters are intended for either isolation or simulation of laser lines. The major laser lines of interest are listed here but if you need a filter for a different laser type please call and we will be glad to supply you with a quote. Laser line filters are offered in three different bandwidths: 1nm, 3nm and 10nm.

All our interference filters are supplied with an individual spectrophotometer trace.

• High transmission and high rejection for complete isolation
• Available at every 50nm throughout the visible and near-IR
• Cut-on and cut-off wavelengths guaranteed to within 10nm
• May be tilt tuned to shorter cut-on/cut-off wavelengths

These are interference filters which provide a sharp cut-off either above or below a particular wavelength. They are useful for isolating regions of the spectrum.

These filters are specified by their center (50% transmission) wavelength. The transmission of the long pass filters is 85% from a wavelength that is 3% greater than the specified wavelength to 2000nm. The transmission of the short pass filters is 85% from a wavelength that is 3% less than the specified wavelength to 425nm (except for the 400nm filter). The width of the transition from cut-on to cut-off is typically 6% or less of the center (specified) wavelength.

The cut-on/cut-off point is shifted to shorter wavelength if the filter is tilted from the normal. This feature can be useful for fine tuning.

• Metallic films produce highly neutral transmission
• Useful for broadband attenuation
• BK7 and Fused Silica substrates for visible and Ultra-Violet applications
• Mounted and unmounted available

These metallic neutral density filters offer the best neutral density over a broad spectral range. A substantial portion of the incident radiation is rejected by reflection rather than absorption, thus reducing the problematic heating found in the absorptive type neutral density filters. These coatings are offered on both BK7 optical glass and synthetic fused silica substrates. BK7 absorbs strongly below 350nm, therefore, synthetic fused silica should be used for applications in the Ultra-Violet.

Mounted and unmounted filters are offered in 25, 30 and 50mm diameters.

Precise Laser Line Filters are available for all popular lasers

Visible Range Filters of 10nm and 40nm bandwidth are available every 50nm throughout the spectrum

Spectral Line Filters allow isolation of all common prominent lines

All Narrowband Filters are supplied in permanent metal rings with engraved wavelength

We offer three ranges of interference filters, laser line filters, spectral line filters and visible range filters. The laser line filters are intended for either isolation or simulation of laser lines. The major laser lines of interest are listed here but if you need a filter for a different laser type please call and we will be glad to supply you with a quote. Laser line filters are offered in three different bandwidths: 1nm, 3nm and 10nm.

The spectral line filters are intended for the isolation of individual lines from common spectral sources. They have a bandwidth of 10nm.

The visible range filters cover 50nm increments from 350 to 800 nm with bandwidths of either 10nm or 40nm. All interference filters are mounted in a metal ring and engraved with the center wavelength and bandwidth.

All our interference filters are supplied with an individual spectrophotometer trace.

• Convenient selection of ND filters from 0 to 3.0 OD
• Detent indexing for fast and easy positioning
• Pre-mounted filters reduce contamination from handling
• Double and single wheels for improved versatility

Our new indexed filter wheels contain a set of neutral density filters. These pre-mounted filters are available in complete 2-wheel or starter 1-wheel versions. Each filter wheel holds six, 1 inch (25mm) filters and is mechanically indexed with detents for ease of adjustment.

The 2-wheel version contains 10 filters of optical density 0.10, 0.22, 0.30, 0.40, 0.52, 1.00, 1.50, 2.00, 2.50. One space in each wheel is intentionally left empty so that the two filter wheels may be adjusted to provide optical densities from 0.0 to 3.0 in 0.1 increments. The 1-wheel version comes with 5 filters that allow for variation in optical density of 0 to 0.5 in 0.1 OD increments.

Both ND filter wheels may be configured conveniently to provide zero attenuation without removing the mount from your beam path. These filter wheels are also available without ND filters and may be used to hold spectral filters or plate beam splitters.

Pinholes are precision etched for exact sizing and clean edges

Standard Pinholes are provided in a non-magnetic stainless steel substrate

High Power Pinholes use copper foil for heat dissipation

We offer two types of pinholes, one for standard applications and one for high power use. The standard version uses stainless steel whereas the high power version uses copper foil. Since they are completely drilled through holes in the substrate they may be used at any wavelength. Because these pinholes are precision etched they are exceptionally round and free of any edge defects. The kerf generated by other drilling techniques is completely eliminated and the resulting holes are consistently round and precise in diameter.

The precision air slits are formed by etching a thin foil of stainless steel. They are extremely light and compact being highly suitable for OEM applications. If required these slits can be supplied with a black coating on the reverse and mounted on a one inch diameter blackened disc for protection and ease of handling.

• Protective eyewear for wavelengths for 190 to 10,600nm
• Filter code name and wavelength printed on glasses
• Eyewear for both single and multi-band wavelengths
• Polycarbonate material with hard coating
• Laser shield windows and curtains in various sizes

The Laser safety glasses and goggles are made of a polycarbonate with a hard coating. They provide protection for use with many common lasers. We offer both single and multi-band wavelength glasses. The glasses have a plastic frame with spring hinges to provide a stable and snug fit. The snug fitting design of the goggles can be worn over your prescription eyewear.

The laser type, wavelength and blocking requirements should be considered to insure the proper selection to meet your needs. Please consult your safety officer to aid you in the selection process.

We offer a range of round unmounted neutral density filters. These unmounted neutral density filters exhibit all of the useful attributes of our mounted filters, but will be found useful in special and built-in applications.

Spectral line filters are intended for the isolation of individual lines from common spectral sources. They have a bandwidth of 10nm.

All our interference filters are supplied with an individual spectrophotometer trace.

We offer a range of square unmounted neutral density filters. These unmounted neutral density filters exhibit all of the useful attributes of our mounted filters, but will be found useful in special and built-in applications.

• Filter wheels for variable attenuation
• Alloy film gives continuous variation
• Optical Density from 0.04 - 2.7
• BK7 or fused silica discs

These variable reflective neutral density filters provide for continuous variation of the attenuation of an optical beam. They are useful for setting the required power level in both experimental and production systems. The attenuating film is an alloy with highly neutral reflective properties over the visible spectrum. It is deposited in a continuously variable thickness over an angular range of 330 degrees of rotation of the disc. This provides a density variation from 0.04 to an optical density of 2 .7. Two types of discs are offered - BK7 and synthetic fused silica. Both have a central hole for ease of mounting. Two sizes are offered to cover most applications. See page 295 for mounted variable ND filter wheels. We offer the mounted ND filter wheels in a motorized version.

The visible range filters cover 50nm increments from 350 to 800 nm with bandwidths of either 10nm or 40nm. All interference filters are mounted in a metal ring and engraved with the center wavelength and bandwidth.

All our interference filters are supplied with an individual spectrophotometer trace.