Two-dimensional photo detector arrays with a cutoff wavelength of 2.5 μm were fabricated on InP/InGaAs
epitaxial wafers with graded buffer layers in a 320x256 geometry on a 12.5μm pitch. Novel growth and fabrication
techniques were employed to fabricate these arrays and optimize the performance. The dark current of the detector was
investigated for a wide range of temperatures. The fabricated detector array was mated with a ROIC and packaged with a
multi-stage TEC and investigated further at the FPA level. The effect of the graded buffer layers on the sensor
performance was investigated and the results were compared to other methods used to develop and fabricate 2D image
sensors on extended wavelength materials.