The GSENSE400BSI sensor is a 4 Megapixels resolution BSI CMOS image sensor with 11μm pixel size. As the first backside illuminated scientific CMOS image sensor in the world, GSENSE400BSI features low readout noise of 1.6 eˉ, high dynamic range of 94dB, and low dark current of 0.27e-/s/pix at deep cooling of -40℃.