US 12,442,762 B2
Optical millimeter-wave oscillator disciplined by rotational spectroscopy
Antoine Jean Gilbert Rolland, Longmont, CO (US); James Greenberg, Boulder, CO (US); Brendan Heffernan, Boulder, CO (US); and Rubab Amin, Longmont, CO (US)
Assigned to IMRA America, Inc., Ann Arbor, MI (US)
Filed by IMRA America, Inc., Ann Arbor, MI (US)
Filed on Mar. 31, 2023, as Appl. No. 18/193,954.
Claims priority of provisional application 63/363,006, filed on Apr. 14, 2022.
Prior Publication US 2023/0333012 A1, Oct. 19, 2023
Int. Cl. G01N 21/35 (2014.01); G01N 21/3504 (2014.01); G01N 21/3581 (2014.01)
CPC G01N 21/3581 (2013.01) [G01N 21/3504 (2013.01); G01N 2201/0612 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A photonic millimeter-wave oscillator, based on a heterodyne beatnote of two continuous wave lasers, configured to provide a narrow linewidth output when a frequency difference between the two continuous wave lasers is disciplined with rotational spectroscopy of molecules using frequency modulation spectroscopy, wherein one of the two continuous wave lasers is frequency- or phase-modulated such that a resulting signal generated through photomixing of the two continuous wave lasers is correspondingly modulated, enabling demodulation of the signal to reveal molecular absorption features.