Narrow Bandpass Filter

In the realm of precision optics, Avantier stands out as a premier manufacturer of Narrow Bandpass Filters. Leveraging state-of-the-art plasma deposition technology, Avantier produces these filters with exacting precision and durability. These filters are designed to isolate an exceptionally narrow wavelength range while maintaining stringent specifications such as low Full-Width Half-Max (FWHM) and deep blocking. They find applications in diverse fields, from laser technology to molecular biology. Avantier offers a wide range of custom options, backed by over fifty years of optical expertise.

Narrow Bandpass Filters
Narrow Bandpass Filters

Narrow Bandpass Filters

Purpose of Ultra Narrow Bandpass Filters: Ultra narrow bandpass filters are designed to isolate a very narrow region of wavelengths while rejecting all other wavelengths of light.

Manufacturing Technology: Avantier uses state-of-the-art plasma deposition technology to manufacture these filters, resulting in precise and durable thin-film filters.

Narrow Bandpass Filter Specifications

  • Center Wavelength (CWL): The CWL is the midpoint of the passband and the location of peak transmission.
  • Full-Width Half-Max (FWHM): The FWHM indicates the width of the passband at half of the maximum transmission. For narrow bandpass filters, the FWHM is less than 6% of the central wavelength.
  • Pass Band Ripple: Some filters have a flat top passband, and the flatness is described by the pass band ripple. Low pass band ripple is desirable, especially in LiDAR applications to prevent spectral drift due to temperature cycling.
  • Blocking: Blocking in the rejection region is described by the optical density (OD), with deep blocking having an OD of 6.


  • Ultra narrow band filters are used in various sophisticated imaging setups and experiments.
  • Applications include laser cleanup, laser line filters, laser excitation filters, flow cytometry, DNA sequencing, PCR diagnostics, fluorescence microscopy, LiDAR, and Raman spectroscopy.
  • They play a crucial role in reducing spectral cross-talk in cytometry and fluorescence in-situ hybridization.
Factory Standard


UV fused silica

Center Wavelengths

from 355 nm to 1064 nm


from 1.3 nm (for a 355 nm CWL filter) to 4.0 nm (for a 1064 nm CWL filter)

Surface Quality


Laser Damage Threshold

0.1 J/cm² @ 532 nm with a 10 ns pulse width

Avantier extends a range of personalized options meticulously crafted to meet your exact specifications. Our accomplished engineering team boasts an extensive history of designing intricate optical systems across a myriad of applications. Whether you’re seeking additional information or aiming to explore our collection of readily available narrow band filters or discuss customized solutions, we invite you to reach out to Avantier. With an unwavering legacy of more than half a century, we’ve solidified our reputation as a dependable source for tailored optical solutions.


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