From Problem To Performance: A Custom Filter That Transformed Imaging Quality

A customer faced inconsistent image quality in a multi-band fluorescence system using laser excitation, with backgrounds failing to remain black and blocking performance varying over time. Traditional filters exhibited inconsistent optical density (OD) across critical laser wavelengths, causing unpredictable results and excessive noise. Standard spectrophotometers could not accurately measure the narrow, deep blocking notches, leaving the problem unresolved.

IDEX Health & Science applied its proprietary KolaDeep™ Spectral Measurement System, capable of resolving ultra-deep blocking adjacent to high-transmission passbands. Measurements revealed sharp OD spikes that explained the imaging inconsistencies. At 747 nm, blocking varied from OD 5 to OD 7 with only a few nanometers shift, a difference causing 100× variation in background darkness.

The solution was a custom Semrock filter engineered to achieve OD > 8 in every laser channel, steeper edges across nine transitions, and wider passbands in all five channels. These improvements deliver brighter fluorescence signals, higher contrast, and dramatically reduced background noise, enabling shorter exposure times or detection of faint signals without sacrificing image quality.

Validation confirmed OD 9 blocking levels, hitting the measurement system’s noise floor. The customer reported consistently deep black backgrounds, improved brightness, and high contrast across all instruments.

This collaboration demonstrates IDEX Health & Science’s expertise in precision filter design, manufacturing, and measurement. From concept through production and validation, we partner with customers to solve complex imaging challenges, providing filters that balance performance, quality, and cost—delivering results that redefine what’s possible in fluorescence imaging.