Enhanced ring resonator dual frequency comb spectroscopy gas sensor

A photonic gas sensing device comprising:

• a housing defining a chamber;
• a photonic gas sensor positioned within at least a portion of the housing, the photonic gas sensor comprising a silicon nitride waveguide having an extended resonant ring waveguide that extends an optical path length within the extended resonant ring waveguide;
• a gas inlet configured for introducing gas into the chamber;
• and
• a light inlet configured to receive light from an external light source.

A method of gas sensing using dual frequency comb spectroscopy, the method comprising:

• directing input light beam from a dual frequency comb into a silicon nitride waveguide positioned within a chamber, wherein the input light beam comprises a first optical frequency comb of a pair of optical frequency combs, wherein the silicon nitride waveguide comprises an extended resonant ring waveguide with spiral waveguide sections;
• introducing a gas sample into the chamber, wherein the gas travels over the silicon nitride waveguide and interacts with an evanescent field of the silicon nitride waveguide;
• combining output optical frequency comb corresponding to output light beam exiting the chamber and a second optical frequency comb from the pair of optical frequency combs to generate a combined optical frequency comb;
• detecting, using an optical detector, the combined optical frequency comb;
• processing the combined optical frequency comb to determine a presence or concentration of a target gas in the gas sample by performing one or more of signal processing or data processing based on the combined optical frequency comb.