# Progress in Avalanche Photodiodes for Laser Ranging

## TL;DR

This paper discusses how avalanche photodiodes improve laser ranging accuracy and outlines their future development.

## Contribution

The paper provides insights into the role and future directions of APDs in high-precision laser ranging.

## Key findings

- APDs offer advantages like high sensitivity and low power consumption over PMTs and SNSPDs.
- Si-APD and InGaAs/InP APD are key examples enhancing laser ranging accuracy and stability.
- Future APD development aims to meet the needs of high-precision and high-frequency laser ranging.

## Abstract

Laser ranging is a high-precision geodetic technique that plays an indispensable role in the field of geodynamics. Avalanche photodiodes (APDs) offer a series of advantages over other photodetector technologies, including photomultiplier tubes (PMTs) and superconducting single-photon detectors (SNSPDs). These advantages include high sensitivity, small size, high integration, and low power consumption, which have contributed to the widespread use of APDs in laser ranging applications. This paper analyses the key role of APDs in enhancing the accuracy and stability of laser ranging through the examination of application examples, including Si-APD and InGaAs/InP APD. Finally, based on the technological needs of laser ranging, the future development directions of APDs are envisioned, aiming to provide a reference for the research of photodetectors in high-precision and high-frequency laser ranging applications.