Case Study: Visible ND Filters 75%, 50%, 25%

Data Table

Specification

Value

ND Transmission 75% ave.

400 – 700 nm T=75+/- 3%

ND Transmission 50% ave.

400 – 700 nm T=50+/- 3%

ND Transmission 25%  ave

400 – 700 nm T=25+/- 2%

Substrate

B270

Dimensions

4 x 4 mm

Thickness

1.0 mm

Scratch/Dig

60/40

Quantity Per Year

200 of each

Case Study: Development of Neutral Density Filters for Diesel Pollutant Monitoring

 

Customer Challenge: We were approached by an existing customer who was developing an environmental monitoring system for diesel pollution. For this project they required a range of custom neutral density filters with transmission levels of 75%, 50%, and 25% average in the 400 to 700 nm visible range. The filters had to pass 24 hours 95% Relative Humidity exposure and severe abrasion as per Mil-C-48497A.

Vortex’s Solution: We were able to produce this suite of ND filters using our magnetron sputtering process which also ensured it passed the tougher than usual environmental requirements. Through careful coating material selection and design simulation we were able to come up with the 3 designs needed.

Outcome: We successfully delivered the three neutral density filters, which worked as predicted in the customers monitoring instrument. The spectral curves are shown below.