An optical receiver having a photodetector, amplifier, feedback loop, and
output circuit is disclosed. The photodetector generates a current
between first and second nodes in response to being illuminated with
light. The amplifier has an input connected to the first node and an
output connected to a third node. The feedback path connects the third
node to the first node, and includes a diode in series with a circuit
element having an impedance greater than a predetermined value, the diode
is connected between the first and fourth nodes. The output circuit is
connected to the fourth node and provides an output signal to an external
circuit. The output circuit can be configured to provide an output signal
that is proportional to the logarithm of the intensity of the light that
illuminates the photodetector.