340nm Bandpass Filter

Context: A non-invasive system for treating and monitoring cataract formation in the human eye lens.

Usage of Filter: The filter is used to isolate the specific fluorescence emission spectrum of tryptophan, which naturally occurs in the lens proteins.

Function: It blocks excitation light and other fluorescence signals, passing only the emission around 340 nm (the peak fluorescence of tryptophan) to the detector.

Result: Enables the system to monitor the "red-shift" of fluorescence (from 340 nm to higher wavelengths like 430 nm) caused by the conversion of tryptophan to N-Formylkynurenine (NFK). This shift serves as a biomarker to grade cataract severity or monitor treatment efficacy.

Context: An optical assembly designed to separate a multi-wavelength light beam into distinct spectral channels for analysis or signal processing.

Usage of Filter: The 340 nm bandpass filter serves as a specific channel selector (often element 78 in the assembly) placed in the path of the collimated light beam.

Function: It selectively transmits the 340 nm ultraviolet component of the incident light while reflecting or absorbing other wavelengths (such as visible or IR bands) to subsequent filters in the sequence.

Result: Achieves precise spectral separation (demultiplexing), allowing the system to independently analyze or route the 340 nm signal without cross-talk from other optical channels.

Context: An instrument used in clinical laboratories to measure biochemical substances in blood or other fluids.

Usage of Filter: The filter is integrated into an optical filtering beam-splitting chip (designated as F1) within the analyzer's light path.

Function: It provides monochromatic light specifically at 340 nm from a broadband light source (like a halogen or xenon lamp) to illuminate the sample cuvette.

Result: Facilitates the quantitative measurement of NADH/NADPH, which absorbs strongly at 340 nm. This allows the analyzer to calculate enzyme activities (e.g., ALT, AST) and substrate concentrations based on the change in absorbance at this specific wavelength.