Professional-Grade Light-Filtering Safety Glasses (Red Lens Model), Black Plastic Frame, for Forensic Evidence Detection, Wavelength Filter Range 560-580 Nanometers (nm)

Red light-filtering glasses Product Application Irradiate physical evidence with monochromatic light from a multi-band light source, and wear light-filtering glasses to observe the fluorescence of the physical evidence. Structural Materials Filter lenses are fixed in eyeglass frames made of plastic. The filter lenses are glass absorption-type long-pass filter lenses. Working Principle The multi-band light source emits monochromatic light, which is referred to as excitation light. When the physical evidence is irradiated with the excitation light, part of the excitation light is reflected by the evidence, while another part is absorbed by it. After absorbing the energy of the excitation light, the physical evidence releases fluorescence. However, the intensity of the fluorescence emitted by the evidence is far lower than that of the excitation light reflected by the evidence—so the fluorescence cannot be seen when observing the evidence directly. The filter lenses of the light-filtering glasses are long-pass filters: they block light with a wavelength shorter than a specific value and transmit light with a wavelength longer than this value. This specific wavelength is called the cut-off wavelength. Since the fluorescence has a longer wavelength than the excitation light, selecting a light-filtering glass whose cut-off wavelength is longer than that of the excitation light but shorter than that of the fluorescence allows the observer to see the evidence’s fluorescence when wearing the glasses. Technical Parameters The red glasses block light with a wavelength shorter than 560 nanometers (nm) and transmit light with a wavelength longer than 580 nanometers (nm).

• OPTICAL DESIGN: Absorption-type long-pass filter lenses block light below 560nm while transmitting light above 580nm, for specialized viewing
• APPLICATION: Enables visualization of fluorescence from physical evidence when used with multi-band light sources in forensic investigations
• FRAME CONSTRUCTION: Durable plastic frame design with securely fixed filter lenses for professional use and comfort during extended wear
• WAVELENGTH FILTERING: Specialized red lenses effectively block shorter wavelength excitation light while allowing longer wavelength fluorescence to pass through
• WORKING PRINCIPLE: Functions by filtering out reflected excitation light while allowing the visualization of fluorescent emissions from evidence materials