Photonic integrated circuit

Photonic integrated circuit comprising:

• a semiconductor substrate;
• an active stack located on the side of a first surface of the semiconductor substrate and comprising:
• a first layer made of a first material having a first refractive index coating the first surface of the semiconductor substrate;
• a second layer made of a second material having a second refractive index coating the first layer;
• and
• a third layer made of the first material coating the second layer;
• at least one photonic component formed in the active stack;
• and
• an optically-absorbent layer located vertically in line with said at least one photonic component and in contact with a surface of the first layer opposite to the second layer, the circuit further comprising a cavity extending, from a second surface of the semiconductor substrate opposite to the first surface, all the way to the first surface of the semiconductor substrate and located vertically in line with said at least one photonic component, the optically-absorbent layer coating a bottom of the cavity.