A hybrid integrated photodetector consisting of array of reach-through avalanche photodiodes and readout integrated circuit chips was developed. The reach-through avalanche photodiode model with separate layer of absorption, charge and multiplication are elaborated. This kind of photodiode is optimized for detection of 905 nm radiation and in that range achieve excellent parameters – high gain, low noise and high speed. Next, the design and properties of the readout integrated circuit with a new-type regulated cascode circuit configuration are discussed. The linear array reach-through avalanche photodiode and readout integrated circuit chips were integrated into a photodetector by using bonder-leading welding techniques. The integrated detector demonstrates the pulse responsivity R ≥ 1×10<sup>6</sup> V/W, the noise equivalent power NEP ≤ 5 pW/Hz<sup>1/2</sup>, and the rise time tr ≤ 3 ns, under pulsed laser irradiation at 905 nm, 100 ns and 10 KHz.