The performance of Absorption Filters is influenced by the thickness of the material itself. Consequently the design of any system utilising such filters is limited to thicknesses which fulfil the specification. This performance requirement may not be possible whatever the thickness with Shortpass and Bandpass Filters. In addition Glass Absorption filters are not fully RoHS compliant.
Envin offer a range of Dichroic Absorption Filters (DAF) which closely match, or exceed, the performance of Absorption Filters but without the thickness constrain. Other performance modifications are also available: For example Longpass filters with a reasonably steep transition edge are only available up to 850nm (RG850 or equivalent). DAF are available for longer transition wavelengths or for values which differ from the Absorption glass specifications.
All of these Filters are hard, durable and environmentally stable and can therefore be produced in a variety of shapes and sizes. This final sizing step is carried out at Envin where finished filters are produced from 1mm square to >100mm diameter. Thickness can be as low as 0.1mm and special considerations such as flatness and parallelism are routinely catered for.
Detailed Optical performance measurements are made using the highest standard Spectrophotometers (Perkin Elmer Lambda 900 & 983G).
Envin is able to offer a complete service from Coating and Filter design to prototyping and full manufacture covering the Ultraviolet, Visible and Infrared regions. Custom products are a speciality of the company.