US 11,835,836 B1
Mach-Zehnder interferometer device for wavelength locking
Yi-Kuei Wu, San Jose, CA (US); Jason Pelc, Sunnyvale, CA (US); Mark Alan Arbore, Los Altos, CA (US); Thomas C. Greening, San Jose, CA (US); Matthew A. Terrel, Campbell, CA (US); Yongming Tu, Redwood City, CA (US); and Mohamed Mahmoud, Sunnyvale, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Sep. 9, 2020, as Appl. No. 17/015,974.
Claims priority of provisional application 62/897,567, filed on Sep. 9, 2019.
Int. Cl. G02F 1/21 (2006.01)
CPC G02F 1/21 (2013.01) [G02F 1/212 (2021.01)] 21 Claims
OG exemplary drawing
 
1. A wavelength locking optical system, comprising:
a first interferometric component configured to receive a first portion of a light and operable to output a first output signal with a first phase;
a second interferometric component configured to receive a second portion of the light and operable to output a second output signal with a second phase different from the first phase;
a third interferometric component configured to receive a third portion of the light and operable to output a third output signal with a third phase different from the first and second phases; and
a controller configured to:
receive the first output signal, the second output signal, and the third output signal;
compare, in a wavelength range, a first slope from the first output signal, a second slope from the second output signal, and a third slope from the third output signal; and
select a largest slope of the first slope from the first output signal, the second slope from the second output signal, and the third slope from the third output signal to wavelength lock a wavelength of the light to a target wavelength.