Responsivity of silicon photodetector in CMOS optical receiver

Abstract EN

In optical communication system the modulated information is processed by an optical source to generate an optical signal.

This signal is transmitted through an optical fiber and finally the photodetector at the receiving end as a first part of optical receiver.

This paper describes the interface circuitry to convert from the optical domain to the electrical domain.

This is used to design an integrated CMOS Optical receiver for gigabit optical communication systems.

The responsivity of photodetectors is studied theoretically in relation with wave length and reverse bias voltages.

The results show that the responsivity of Si photodetector will not decreased if the reverse bias voltage decreases when it is operated below 4.5 µm wave length, thus the photodetector offers acceptable responsivity at lowest bias voltage this means low size and low cost of photodetector.

The results also show 1.1 µm wave length is a cut off wave length.

MATLAB program are designed in order to achieve this task at high speed and accuracies.