Bertin Technologies has collaborated with F4E to develop expertise in retroreflector-based calibration methods for optical diagnostic systems operating in constrained or harsh environments. In many situations, permanently installing a calibrated light source is impossible or impractical due to environmental conditions, limited access, or cost. Conventional retroreflector approaches rely on long-term material reflectivity stability, which can drift over time and introduce biases.

Main advantages and potential applications

• Single-material device manufactured by a simple, reproducible process; compatible with visible, infrared, and radar wavelengths.
• Adaptable configuration to areas where optical transmission efficiency needs to be monitored over time: simultaneous measurement of retroreflector reflectivity and optical system transmission.
• No in situ calibrated light source required: ideal for constrained, remote, or inaccessible installations (underwater, furnaces…) and for high radiation environments (nuclear, space…)
• Reverse application possible: deposition monitoring via transmission loss measurement.