240nm UVC Optical UV Filter FWHM 20nm Overview

The 240nm UVC optical UV filter (FWHM 20nm) is a narrow-band filter featuring a center wavelength of 240nm and a full width at half maximum (FWHM) of 20nm. It achieves high transmission in the 230–250nm range while providing high blocking (OD4) across the 200–1100nm spectrum. Utilizing all-hard dielectric coating technology, the filter layers exhibit exceptional density and radiation resistance, ensuring stable, long-term operation when exposed to high-energy light sources such as deuterium lamps and UV LEDs.

The spectrum Curve Of 240nm UVC Optical UV Filter FWHM 20nm

240nm UVC Optical UV Filter FWHM 20nm Technical Specifcation

• Centerwavelength: 240+/-3nm
• FWHM: 20+/-3nm
• Transmission Peak >14%
• Blocking depth: 200-1100@OD4 average
• Standard Size in stock: Dia25.4*6mm mounted

Other Deep UV Interference filter and UV Bandpass Filter In Stock List:

Coligh Custom capability of UV bandpass filters

• Custom different center wavelength
• Custom different FWHM
• Custom special angle of incidence
• Custom shape and dimention
• Custom option for mounting

240nm UVC Optical UV Filter FWHM 20nm Applications

Deep-UV Raman Spectroscopy

244 nm is a common excitation wavelength for deep-UV Raman spectroscopy. Before the sample is excited, it is essential to filter out the plasma glow and other stray spectral lines generated by the 244 nm laser system. A 240/20 nm UV bandpass filter transmits the 244 nm laser while blocking nearby spectral noise, facilitating the acquisition of Raman signals with a high signal-to-noise ratio.

Water Quality Monitoring

Certain types of dissolved organic matter (DOM) and nitrates exhibit sharp, characteristic absorption peaks in the 230–250 nm range. A 240/20 nm UV filter can be positioned between a deep-UV LED or miniature pulsed xenon lamp and a photoelectric sensor to enable more precise monitoring of transmitted light signals and reduce interference from other background substances in the water sample.

NDUV – Specific Pollutant Gases and VOCs

Certain volatile organic compounds (VOCs)—such as benzene derivatives—and specific pollutant gases found in industrial emissions exhibit characteristic absorption in this wavelength range. A 240/20 nm UV interference filter can be integrated into gas analyzers to isolate specific wavelengths and calculate absorbance.