Electromagnetic radiation detection circuit for pulse detection including an amplifying transistor and a coupling capacitor

An electromagnetic radiation detection circuit comprising:

• a photodetector configured to transform the received electromagnetic radiation into an electric current;
• a bias circuit connected to terminals of the photodetector, the bias circuit receiving a first part of a current emitted by the photodetector;
• an amplifying circuit, which is different from the bias circuit, and comprising an amplifying transistor formed by a field-effect transistor or a bipolar transistor,
• the field-effect transistor or the bipolar transistor having a first electrode forming an input terminal of the amplifying circuit coupled to a first terminal of the photo-detector so as to receive a second part of the electric current emitted by the photodetector, the first electrode being a source electrode or an emitter electrode,
• the field-effect transistor or the bipolar transistor having a second electrode coupled to an output terminal of the electromagnetic radiation detection circuit, the second electrode being a drain electrode or a collector electrode, and
• the amplifying circuit being configured so that the electric current applied to the first electrode flows through the amplifying transistor and so as to provide this electric current on the output terminal with an impedance higher than an impedance on the first electrode;
• a voltage source connected to a control electrode of the amplifying transistor;
• and
• a passive electric load connected to the second electrode of the amplifying transistor,
• wherein the source terminal or the emitter terminal of the amplifying circuit is connected to a terminal of the photodetector by means of a coupling circuit configured to allow only a part of the signal emitted by the photodetector to pass through the coupling circuit.