US 12,308,601 B1
Wavelength locker
Long Chen, Marlboro, NJ (US); and Christopher Doerr, Middletown, NJ (US)
Assigned to ACACIA COMMUNICATIONS, INC., Maynard, MA (US)
Filed by Acacia Communications, Inc., Maynard, MA (US)
Filed on Mar. 31, 2023, as Appl. No. 18/129,645.
Application 18/129,645 is a continuation of application No. 17/092,979, filed on Nov. 9, 2020, granted, now 11,621,536.
Application 17/092,979 is a continuation of application No. 16/285,912, filed on Feb. 26, 2019, granted, now 10,833,472, issued on Nov. 10, 2020.
Application 16/285,912 is a continuation of application No. 15/851,474, filed on Dec. 21, 2017, granted, now 10,263,385, issued on Apr. 16, 2019.
Claims priority of provisional application 62/437,141, filed on Dec. 21, 2016.
Int. Cl. H01S 3/106 (2006.01); H01S 3/00 (2006.01); H01S 3/13 (2006.01); H01S 3/131 (2006.01); H01S 5/068 (2006.01); H01S 5/0687 (2006.01); H01S 5/14 (2006.01); H01S 5/02 (2006.01); H01S 5/0683 (2006.01)
CPC H01S 3/1305 (2013.01) [H01S 3/0014 (2013.01); H01S 3/1062 (2013.01); H01S 3/1317 (2013.01); H01S 5/06821 (2013.01); H01S 5/0687 (2013.01); H01S 5/141 (2013.01); H01S 5/021 (2013.01); H01S 5/06837 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
measuring, by a wavelength locker, a phase in a period of a wavelength filter of a portion of light to produce a measured phase, wherein measuring the phase of the portion of light using the wavelength filter includes:
inputting the portion of the light into a length imbalanced Mach-Zehnder interferometer with a 90 degree optical hybrid coupled to a first photodetector and a second photodetector;
transmitting, from the 90 degree optical hybrid, an in-phase (I) signal to the first photodetector and a quadrature (Q) signal to the second photodetector;
receiving, from the first photodetector the I signal and receiving from the second photodetector the Q signal in response to the light; and
calculating a wavelength of the light based on the I and Q signal to produce a calculated wavelength;
comparing the calculated wavelength of light to a desired wavelength; and
changing the wavelength of the light to match the desired wavelength based on the calculated wavelength not matching the desired wavelength.