12. The detector of claim 11 wherein the gates of the first and second n-channel FET s of the detector are about 40 microns wide and the gates of the transistors of the amplifier stage are only about 3 microns wide.
11. The detector of claim 10 further comprising: an amplifier stage comprising a p-channel FET and an n-channel FET connected as an inverter amplifier with common gates connected to the second capacitor, and common drains connected to an output lead such that when the voltage on the second capacitor changes sufficiently from its quiescent value, the output lead is switched in polarity.