Adaptable filters for fluorescence analysis

High-End fluorescence microscopes as well as fluorescence spectrometers require optical filters in order to separate the fluorescence signal from the excitation light. Unfortunately, different applications call for different fluorophores and thus numerous optical filter sets. This often results in unnecessary costs. Optics Balzers is now offering linear variable filters (LVF) which allow to address all kinds of fluorophores with just one filter set. Sliding the filters in respect to each other allows creating a bandpass filter with arbitrary center wavelength and half-width. At the same time, exceptionally steep spectral edges ensure optimal separation between excitation and emission signals.In contrast to off-the-shelf filters the LVF provided by Optics Balzers set new standards in spectral performance. Transmissions of more than 95% while blocking the out-of-band signal with OD5 allow driving the image quality as well as analyzing sensitivity to the maximum. Due to the unique manufacturing concept used, the LVF show minimal auto-fluorescence and an undisputed long-term stability.