Optoelectronic device for detection of a substance dispersed in a fluid

An optoelectronic device for detection of a target substance dispersed in a fluid, the device comprising:

• a light source adapted to emit a light radiation having a tunable wavelength (λs);
• an integrated electronic circuit comprising a photonic circuit operatively coupled with said light source;
• a control unit operatively coupled with said light source and said photonic circuit;
• wherein said photonic circuit comprises:
• an optical coupler comprising a first active surface optically coupled with said light source to receive a light radiation emitted by said light source;
• a first detector optically coupled with said optical coupler to receive a first light radiation corresponding to a first portion of a light radiation transmitted by said optical coupler, said first detector being adapted to provide first detection signals indicative of an optical power of said first light radiation, said first detector being operatively coupled with said control unit to transmit said first detection signals to said control unit;
• an optical resonator optically coupled with said optical coupler to convey and transmit a second light radiation corresponding to a second portion of the light radiation transmitted by said optical coupler, said optical resonator comprising a ring optical path and, in at least a portion of said optical path, a second active surface adapted to come into contact with said fluid and comprising a material capable of selectively absorbing said target substance, a resonance wavelength (λr) of said optical resonator varying as a function of the quantity of said target substance absorbed by said second active surface;
• a second detector optically coupled with said optical resonator to receive the second light radiation transmitted by said optical resonator, said second detector being adapted to provide second detection signals indicative of the optical power of said second light radiation, said second detector being operatively coupled with said control unit to transmit said second detection signals to said control unit;
• said control unit configured to receive and process said first and second detection signals and provide, in response to said first and second detection signals, first control signals to tune the wavelength (λs) of the light radiation emitted by said light source wherein an optical power difference (ΔS) between said first and second light radiation is set to zero.