A comparison is made of conventional pin photodetectors and modern uni-traveling-carrier photodetectors based on InGaAs/InP heterostructures. The differences in the designs of heterostructures of these photodetectors are considered and the resulting features of their functioning are analyzed. It is shown that with comparable photosensitivity, the saturation photocurrent of uni-traveling-carrier photodetectors is approximately four times greater than that in conventional pin photodetectors. Devices with a photosensitive area 40 μm in diameter reach the saturation current at an input optical power of 10–12 and 60–70 mW for pin and uni-traveling-carrier photodetectors, respectively (reverse bias voltage of 5 V).