Silux-37xx Series

Motivation of Silux

There has been a need for a radiometric unit of measure that is better correlated to monochrome silicon imaging sensor response than the lux unit, especially if thinking about night vision cameras, etc. Scientifically there was a proposal for a new reference unit for such systems called the Silux (acronym Silicon and lux). The recent convergence of spectral responsivity curve shapes of different commercial low-light CMOS imaging sensors, particularly in the NIR band motivated the silux unit of spectrally weighted irradiance which is based on a spectral efficacy function silux(λ), which is a weighted average of the spectral responsivity curves of recently commercialized NIR-enhanced CMOS imaging sensors, and a counterpart to V(λ) for the lux unit [1].

Application of Silux

The main application for a silux optometer is the characterization of how well a particular low-light outdoor irradiance condition will produce signal in a CIS-based imaging system. 

What is 1 silux?

The silux unit of spectrally weighted irradiance which is based on a spectral efficacy function silux(λ), which is a weighted average of the spectral responsivity curves of recently commercialized NIR-enhanced CMOS imaging sensors, and a counterpart to V(λ) for the lux unit. In [1] a scaling of the unit so that 1 silux/sr is defined as the in-band radiance of a 2856 K blackbody at a luminance of 1E-04fL.

[1] Richards, Hübner, Silux: A Unit of Silicon Detector-Weighted Irradiance, Proc. SPIE 12533, Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XXXIV, 125330J (14 June 2023); doi: 10.1117/12.2663668, 2023