Opticology, Inc. offers custom optical filters fabricated from colored glass manufactured by Schott Glass Technologies and other raw material suppliers.  These filters can be supplied from any of the 80 or so available glass types to your exact specification for research, engineering, or production OEM systems.

Colored glass filters can be used as an economic alternative to thin-film coated filters.  They work on the principal of absorption, are generally more durable than coated filters, easier to clean and handle.  They also have advantages over metallic thin-film density filters, as colored glass can withstand radiation from high-power lasers without damage*.

Applications include:
Neutral Density Filters (Spectrally flat attenuation).
High-Power Laser Attenuation
Longpass, Shortpass or Bandpass Filter
Gaussian Compensator (Apodizing Filter)
Base substrate for blocking prior to applying thin-film coating

Neutral Density Filter Sets

Opticology offers calibrated Neutral Density Filter Sets fabricated from neutral gray glass. These filters offer relatively flat transmission from 400nm out to the near infra-red.

Unlike most filter sets, these are made from the same thickness for each density value. Therefore, if used in a convergent beam, there is no need to refocus when changing filters.

We offer a set of 6 equal-thickness filters with nominal optical densities (OD) of 0.1, 0.3, 0.6, 1.4, and 4.0.  The filters are available from stock in 1” diameter, or custom sizes are available with reasonable leadtimes. 

Any of our 1” stock filters are available mounted in a black anodized aluminum cell – please inquire.

For ordering and pricing information of an Equal-Thickness Neutral Density Filter Set please call 212-243-4328 or email filters@opticology.com

Any of our 1” stock filters are available mounted in a black anodized aluminum cell.

Custom Filters Polished to Transmission

Colored filter glass has applications in the ultraviolet, visible, and infrared regions of the spectrum and the properties of the transmission change depending on thickness.

Unlike most optical shops, Opticology polishes filter glass to your desired transmission not merely to a specified thickness.  Since colored filter glass can vary as much as 20% from melt (material lot) to melt, for accurate filtering applications polishing to thickness is unacceptable.*

Ultra-Precision Filters

In addition to polishing-to-transmission, Opticology fabricates filter glass to high dimensional tolerances and with precision quality surfaces for laser, astronomical, or military/defense applications. Parts can be finished to precision to the following specifications:

Flatness: 1/20 wave Thickness: +/-0.02mm Parallel: 10 arcseconds Scratch/Dig: 10/5

High quality dielectric anti-reflection coatings can be added to the surfaces if required reducing surface reflections to <0.2% narrowband or <0.5% broadband.