340nm Broadband UV Filter FWHM 120nm Overview

The 340nm Broadband UV Filter (FWHM 120nm) features a center wavelength of 340nm and a full width at half maximum (FWHM) of 120nm. It provides broad spectral transmission across the 280–400nm range, allowing for the simultaneous transmission of UVA and UVB radiation. Utilizing a UV-grade fused silica substrate and precision hard dielectric coatings, the filter maintains high, flat transmission within the passband while delivering an optical density (OD) of 4 for blocking in the 410–650nm range. It is suitable for applications such as solar UV monitoring, broadband phototherapy, and multi-wavelength UV curing.

The spectrum Curve Of 340nm Broadband UV Filter FWHM 120nm

340nm Broadband UV Filter FWHM 120nm Technical Specifcation

• T>85 @ 280-380nm
• OD4 @410-650nm
• Standard Size in stock:  D25.4*6mm or custom

Other  Narrow and Wideband UV Bandpass Filter Filter In Stock List:

Customization Capability of UV Bandass Filter

340nm Broadband UV Filter FWHM 120nm Applications

UV Curing

Industrial UV light sources—such as high-pressure mercury lamps, xenon lamps, or high-power broadband UV-LED arrays—emit visible glare and significant infrared (IR) heat radiation alongside ultraviolet light. Direct exposure to this IR heat can cause heat-sensitive substrates to warp or burn. A 340/120nm bandpass filter allows the effective UV wavelengths (260–380 nm) required to trigger photoinitiator reactions to pass through with minimal loss, while reflecting or absorbing visible light and near-infrared heat.

Industrial Fluorescence Machine Vision

Fluorescent penetrants or magnetic particles are commonly used in applications such as flaw detection for aerospace components, leak detection in automotive engines, and particle inspection on semiconductor wafer surfaces. The excitation wavelengths for these fluorescent materials often span a broad UV range. A 340/120nm UV filter transmits broadband UV light (260–380 nm) to excite fluorescent materials across a large area of ​​the workpiece surface while blocking stray visible light from the source.

Broadband Fluorescence Spectroscopy and Forensic Analysis

Biological samples, organic pollutants in water, and forensic evidence—such as bodily fluids, fingerprints, and fluorescent dyes—often require a broad UV spectral range to elicit the strongest fluorescence emission. Insufficient bandwidth can result in inadequate excitation energy and weak signals. A 340/120nm UV bandpass filter can be integrated into portable spectrometers to enhance the excitation intensity of fluorescence signals.