US 11,703,317 B2
Heterodyne photonic integrated circuit for absolute metrology
Richard Lee Kendrick, San Mateo, CA (US); and Joseph Marron, Manhattan Beach, CA (US)
Assigned to RAYTHEON COMPANY, Waltham, MA (US)
Filed by RAYTHEON COMPANY, Waltham, MA (US)
Filed on Dec. 21, 2021, as Appl. No. 17/558,126.
Application 17/558,126 is a continuation of application No. 16/990,133, filed on Aug. 11, 2020, granted, now 11,221,204.
Prior Publication US 2022/0187055 A1, Jun. 16, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G01B 9/02 (2022.01); G01B 9/02003 (2022.01); G01B 9/02001 (2022.01); G01B 9/02015 (2022.01); G01B 9/02055 (2022.01); G01B 11/14 (2006.01); G01D 5/353 (2006.01); G02B 6/125 (2006.01)
CPC G01B 9/02051 (2013.01) [G01B 9/02003 (2013.01); G01B 9/0207 (2013.01); G01B 9/02008 (2013.01); G01B 9/02027 (2013.01); G01B 9/02028 (2013.01); G01B 9/02049 (2013.01); G01B 11/14 (2013.01); G01D 5/35303 (2013.01); G02B 6/125 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A digital measuring device, the digital measuring device comprising:
a first ring resonator configured to produce a first frequency comb of light and direct at least a portion of the first frequency comb of light at an object;
at least one waveguide structure configured to combine a reference beam with light reflected from the object to produce a measurement beam;
a first multiplexer configured to split the measurement beam into a plurality of channels spaced in frequency;
a controller configured to measure a distance between the digital measuring device and the object based on the plurality of channels; and
wherein the controller is further configured to determine the distance between the digital measuring device and the object by using an error metric to correlate the intensity values of the plurality of channels with sinusoidal intensity values.