Case Study: 4000nm Short Pass Filter
Data Table |
|
Specification |
Value |
50% T% |
4000 +/- 40 nm |
Transmission Range |
2000 – 3900 nm |
Blocking Range |
4100 – 6000 nm |
Peak Transmission % |
T> 90 % ave. |
Substrate |
Silicon |
Dimensions |
12 x 12 mm |
Thickness |
1 mm |
Scratch/Dig |
60/40 |
Quantity Per Year |
200 |


Case Study: Short Wave Pass Filter to transmit hydrocarbon signatures
This short-wave pass filter was designed for a customer with a gas sensing application, they wanted to look at a range of hydrocarbon absorption peaks but needed to screen out some interference from gases such as CO₂, CO, NO and NO₂, these gases could cause a false positive result within the system. The filter was being used with a lead selenide (PbSe) detector which has a sensitivity range up to roughly 5.5µm, so it was important that the blocking extended beyond this. The filter shown above was produced and found to be more than adequate.