Case Study: Laser Attenuator Filters

Data Table

Specification

Value

Transmission

0.1% T at 1064 nm

Substrate

Fused Silica

Dimensions

10 mm

Thickness

1.5 mm

Scratch/ Dig

40/20

Quantity Per Year

600

Customer Problem: The customer required a high density, low transmission laser attenuator for 1064 nm. The specification required a Transmission of 0.1% +/-0.026%. This is quite a low and difficult transmission to measure. The specification can also be expressed in terms of Optical Density (OD), i.e. OD to be within the range 2.9 to 3.13.

Our Solution: Historically these are often made by polishing an IR low transmitting glass to a calculated thickness, based on melt data to achieve the Transmission required but it is often a ‘trial and error’ process with low yields. There is the added problem that many of the candidate glasses are stain prone and this can result in a deterioration of performance over time. A coated product ensures less ‘trial and error’ and with Vortex’s state-of -the-art sputtering process a durable and stable product fit for use for many years

Outcome: Vortex designed and manufactured an all-dielectric solution for this product. Measuring low Transmission is tricky, so a known OD standard for 1064 nm was also be used to check performance, see Fig 1 above.