Selecting Eyewear - Laser Protective
There is an ever expanding array of complex and sophisticated laser systems used in material processing. Laser safety officers in military, medical, reasearch and development applications demand high performance laser safety eyewear options for their laser personnel.
When selecting the most appropriate laser protective eyewear solutions the LSO needs to consider the working environment, viewing conditions, operational and performance specifications of the laser as well as beam delivery systems. The ultimate goal in selecting laser eye protection is to provide comfortable and stylish eyewear that laser personnel will wear with protection levels (OD) that properly attenuates or reduces potentially hazardous laser exposures to levels safely below maximum permissible exposure (MPE) levels.
laservision laser protective eyewear is available in variety of styles. The styles are available in absorptive or reflective dielectric thin film technology.
Absorptive lens filters are made using high impact, high optical quality polycarbonate or glass materials where light absorption at a specific laser wavelength is expressed in terms of optical density (OD) and is calculated by the following equations:
OD = -log10T = -log10(I/Io ) = log10 (1/T )
T = Transmittance at the wavelength of interest
Io = Intensity of incident beam
I = Intensity of transmitted beam
Polycarbonate laser protective eyewear provide laser safety officers with excellent low cost, lightweight safety solutions but may have slightly lower ODs and visible light transmission (VLT) values than absorbing glass filters or dielectric coated filters.
Absorbing glass filters generally provide higher
optical densities, better VLT values but at a slightly higher cost per pair when compared to polycarbonate safety eyewear.
Thin-film coated filters provide precise protection at specific laser wavelengths and also have excellent VLT values. This is accomplished by applying physical vapor deposition (PVD) technology of dielectric materials upon various optically transparent or absorptive substrates. Precise (? wavelength thickness) vapor depositions of alternate HI-LO index of refraction dielectric coatings or films are applied directly to absorptive polycarbonate or glass filter materials. This technology provides laser protection by reflective as well as absorptive properties.
By capitalizing on the desirable absorptive and reflective characteristics of various laser filter technologies laservision can also bond or laminate two (or more) types of filters together utilizing special optical adhesive lamination technology to extend the spectral protection range of a single type of eyewear filter to cover a broader range of laser wavelengths.
We use an instrument called a spectrophotometer to measure optical densities. The measurements of laser protective filters are recorded over an entire range of wavelengths from which optical density and visible light transmission data is generated to verify the absorptance, reflective or transmissive properties. This information is analyzed and permanently recorded on the eyewear.
The following sections display frame and filter options for laser protective eyewear. If you have any further questions please contact us at www.lasersafety.com, or call us at 1-800393-5565. We are available standard business hours Monday-Friday 8 am to 5 pm to answer any of your questions.