Bandpass Filters are commonly used to isolate narrow emission or absorption features from a broad spectral range within analysis instrumentation. Multiple filters are often used within a selction mechanism such as a filter wheel. These filters are traditionally manufactured using cemented structures utilising soft coatings. Envin offers such filters in a wide range of wavelengths […]
Filters for use in Fluorescence applications are a speciality of the company and include both Excitation and Emission products. Designs for many different Fluorophores are available including standards such as Ethydium Bromide and for more demanding applications such as ‘Cy dyes’ or ‘Qdots’. Filters with steep transition edges and high blocking levels (OD6 +) are […]
Shortwave pass optical thin film filters are a variety of edge filters: optical thin film filters that split the waveband into two component regions of specified wavelengths. One waveband is transmitted, while the other is rejected (i.e. reflected) and can be used as a secondary signal in its own right. The name of ‘shortwave pass’ […]
Long pass Filters separate wavelength regions by reflecting the shorter wavelengths whilst transmitting longer wavelengths. Both portions of light can be utilised. The position of the filter is defined by the transition or ‘half power’ wavelength. The width of the transmission and reflection zones can be specified independently as can the steepness of the transition […]
Bandpass filters or band-pass filters work by allowing a specific range of wavelengths of light to be transmitted through the filter – they literally ‘pass’ a ‘band’ of wavelengths. The filter allows signals to be transmitted between two frequencies. Some bandpass filters require external sources of power to work such as filter circuits, these are […]
Notch Filters or ‘Minus Filters’ are used to remove selected unwanted wavelengths, such as laser lines, by reflection. High transmission values in the adjacent passbands and steep transition edges are often necessary to maximise the required wavelengths. Notch widths can be produced to suit the application requirements. Steep transition edges with low ripple and high […]
High Reflectors or Dielectric Mirrors are used to steer light by reflection. The reflectivity is normally higher than that obtained with metallic mirrors. They can be for a single wavelength, multiple wavelengths or broadband in nature. Normally the performance outside the reflective area is not specified. If it is specified it falls under the products […]
