Linear Variable Bandpass Filters

Linear Variable Bandpass Filter or continuously variable bandpass filters are precision-coated wedge-shaped bandpass optical filters with central wavelengths changing in a linear relationship corresponding to the length of the filter, transmitting a specific range of light around the center wavelength while blocking the unwanted spectrum. This spatial variation in optical properties allows for tunable transmission characteristics via position shifting along the longer dimension of the filter. A single linear variable bandpass filter can fulfill the function of multiple homogeneous filters or a grating-based monochromator. Linear variable bandpass filter offers a feasible measure to adjust the center wavelength by sliding the filter relative to the light source. Linear variable bandpass filters find widespread use in spectroscope, hyperspectral imaging, and fluorescence microscope applications, where they play a crucial role in isolating specific spectral bands for analysis. 

Shalom EO offers standard and custom Linear Variable Bandpass Filters. Utilizing an advanced wedge-shaped multi-layer coating technique, these filters offer high spectral resolution and low optical loss over a broad tunable spectral range. As shown in the transmission curves, our linear variable bandpass filters offer sharp spectral cut-on and cutoff ensuring efficient rejection of undesirable light and high transmission within the passband to maximize optical performance at the required wavelength. Compact, lightweight construction renders them suitable for integration into portable and space-constrained optical setups. Through manipulation of the slope of the thin-film layers, a specific linear variation in transmission wavelength can be achieved, enabling precise spectral control and tuning for various applications. With their wide operating range, high transmission efficiencies, and robust microstructure, these linear variable filters provide reliable performance in demanding laboratory and industrial environments. 

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