Thin-film tunable filters for hyperspectral fluorescence microscopy

Area of Science:

• Biomedical Optics
• Fluorescence Imaging
• Spectroscopy

Background:

• Hyperspectral imaging captures contiguous spectral data, initially for remote sensing but now applied to biological fluorescence imaging.
• Spectral filtering is crucial for hyperspectral system sensitivity and specificity, with acousto-optic tunable filters (AOTFs) and liquid crystal tunable filters (LCTFs) being common but having limitations.

Purpose of the Study:

• Introduce a novel thin-film tunable filter (TFTF) for hyperspectral imaging.
• Compare the performance of a TFTF-based hyperspectral microscopy system against a commercial AOTF-based system.
• Evaluate the suitability of TFTFs for biomedical imaging applications.

Main Methods:

• Characterized light transmission, wavelength calibration, and optical density (OD) of both TFTF and AOTF systems.
• Assessed the systems' ability to discriminate between green fluorescent protein and autofluorescent lung tissue.
• Utilized hyperspectral microscopy for comparative analysis.

Main Results:

• The TFTF demonstrated a high percentage of light transmission and high out-of-band optical density compared to AOTFs.
• The TFTF-based system showed comparable or improved performance in discriminating fluorescent signals from autofluorescence.
• TFTFs offer an alternative hyperspectral filtering approach with enhanced optical properties.

Conclusions:

• Thin-film tunable filters (TFTFs) present a viable alternative for hyperspectral filtering, offering superior transmission and out-of-band blocking.
• These improved characteristics make TFTFs suitable for advanced biomedical imaging devices beyond microscopy.
• TFTFs enhance the potential for sensitive and specific spectral analysis in biological and medical contexts.