| 摘要 |
<p>The present invention provides an avalanche photo-diode detector arrangement comprising two avalanche photo-diodes, which are each reverse biased to just below their breakdown voltage, are arranged back-to-back and are arranged in series with an oscillating voltage source such that the photodiodes exceed their breakdown voltage out of phase with each other. The oscillating voltage has a period of at least twice and preferably between 4 and 32 times, the avalanche zone transit time of the photo diodes. The detector arrangement achieves low noise and is able to distinguish dark counts.</p> |
