Germanium Avalanche Photodiode (APD) Chips are a type of photodiode that uses germanium as the light-absorbing material. APDs are photodiodes that use an internal avalanche multiplication process to achieve high gain, sensitivity, and low noise levels, making them suitable for use in low light level applications.
Germanium APDs can detect light in the near-infrared (NIR) region up to approximately 1.8 micrometers, which makes them useful in telecommunications, spectroscopy, and other applications that require detection in this range. They can also be used in high-speed optical communications systems, fiber optic testing equipment, and range finding applications.
Germanium APDs have several advantages over silicon APDs, including a higher gain-bandwidth product, a higher sensitivity, and a lower dark current, which reduces the noise floor. However, they also have some drawbacks, such as a higher cost and a lower maximum operating temperature.