The IG22X500S4i from Laser Components is a Photodiode with Wavelength Range Cut off Wavelength: 2.2 µm, Capacitance 160 pF, Dark Current 0.1 to 1 nA, Responsivity/Photosensitivity 0.1 to 1.9 A/W, Active Area Diameter 500 µm. More details for IG22X500S4i can be seen below.