Noise measurements on germanium avalanche photodetectors

✍ Scribed by Hof, C. A. ;Bakker, T.

• Book ID: 104749247
• Publisher: Springer
• Year: 1974
• Tongue: English
• Weight: 665 KB
• Volume: 29
• Category: Article
• ISSN: 0003-6994
• DOI: 10.1007/bf00384145

✦ Synopsis

In this p a p e r the overall-noise in a photodetection system, consisting of a Germanium avalanche-photodiode and a low-noise amplifier is determined. It turns out, that the main contributions to the overall-noise stem from the bulk-and guardring leakage currents and from the amplifier.

The main parameter of interest for laser rangefinder applications is the noise-equivalent signal current, being equal to the peakvalue of the equivalent noise current at the amplifier input, divided by the avalanche multiplication factor.

It turns out, that the optimum bias conditions for low-noise operation are rather temperature dependent. It is argued that current control is preferable to voltage control in order to stabilize against temperature variations. The optimum bias conditions and the corresponding minimum noise-equivalent signal currents are measured as functions of the ambient temperature.

Besides the noise measurements the dynamic responses of some types of photodetectors are compared. It turns out, that various types of photoresponses are possible, dependent on the construction details of the device.