Dear colleagues,

I’m reaching out to see if anyone has experience measuring camera linearity for SWIR cameras, particularly the Goldeye G-032 SWIR TEC, 14-bit.

I recently conducted linearity measurements on this camera and got some unexpectedly large nonlinearity values. I wanted to check if anyone else has similar or different experience with camera (non)linearity.

What I’m looking for:

• General linearity performance data for other SWIR cameras
• Linearity measurements for the Goldeye G-032 SWIR TEC specifically
• Typical nonlinearity ranges I should expect for InGaAs-based SWIR sensors
• Common pitfalls or sources of error in SWIR linearity measurements

My setup:

• I used Goldeye G-032 SWIR TEC, 14-bit.
• I shined a cw 1313 nm laser light source onto a piece of paper and the camera was looking at the laser spot on the paper using an objective. Spectral filters were in front of the camera to reduce signal from other wavelengths.
• I put optical ND filters into the laser beam. Took images for each transmission (1, 0.8, 0.5, 0.4, 0.25, 0.13, 0.09, 0.07, 0.04)
• The shape of the image on the camera stayed the same (except the px values of course), so I compared the px values against the supposed pixel from the transmission.

Any insights, data, or references would be greatly appreciated!

Thanks in advance!