Method and apparatus for conducting heterodyne frequency-comb spectroscopy

An apparatus for conducting heterodyne frequency-comb spectroscopy, comprising:

• first and second frequency-comb generators, each frequency-comb generator including:
• a laser cavity for propagating optical power traveling therein;
• an output coupler optically communicating with the laser cavity for receiving the optical power and generating a continuous wave laser beam from a first output portion of the optical power, the continuous wave laser beam defining a spectrum of light including a plurality of optical frequencies spaced by a frequency;
• a beam combiner operatively connected to the first and second frequency-comb generators, the beam combiner combining the first and second continuous wave laser beams generated by the first and second frequency-comb generators and providing the same as a combined beam having a plurality of beat frequencies dependent upon the optical frequencies of the spectrums of light defined by the first and second continuous wave laser beams.

A method for conducting heterodyne frequency-comb spectroscopy, comprising the steps of:

• generating at least one continuous wave comb defined by a plurality of optical frequencies;
• down-converting the optical frequencies of the at least one continuous wave comb;
• and
• determining an optical spectrum for the at least one continuous wave comb from the down-converted optical frequencies.

A method for conducting heterodyne frequency-comb spectroscopy, comprising the steps of:

• generating at least one continuous wave comb defined by a plurality of optical frequencies;
• designating the plurality of optical frequencies to generate modulations at lower beating frequencies;
• and
• detecting the lower beating frequencies to observe an optical spectrum.