Koheron PD4Q is a 4-quadrant photodetector with 100 kV/A transimpedance gain and 250 kHz bandwidth. The PD4Q outputs three voltages: X = (A+D)-(B+C), Y = (A+B)-(C+D) and SUM = (A+B+C+D)/4. Thanks to its low noise and high dynamic range, the PD4Q can measure laser beam position with a resolution below 20 nm in a 10 kHz bandwidth.

Please refer the attached datasheet for complete specifications and confirm the model.