US 12,255,682 B2
Optical time-domain reflectometer (OTDR) including channel checker
Vincent Lecoeuche, Tarentaise (FR)
Assigned to VIAVI SOLUTIONS INC., Chandler, AZ (US)
Filed by VIAVI SOLUTIONS INC., Chandler, AZ (US)
Filed on Feb. 26, 2024, as Appl. No. 18/587,453.
Application 18/587,453 is a division of application No. 17/736,273, filed on May 4, 2022, granted, now 11,942,986.
Claims priority of application No. 21306326 (EP), filed on Sep. 24, 2021.
Prior Publication US 2024/0195497 A1, Jun. 13, 2024
Int. Cl. H04B 10/07 (2013.01); H04B 10/071 (2013.01); H04B 10/2537 (2013.01); H04B 10/50 (2013.01); G01D 5/353 (2006.01); G01M 11/00 (2006.01); H04B 10/60 (2013.01); H04B 10/61 (2013.01)
CPC H04B 10/071 (2013.01) [H04B 10/2537 (2013.01); H04B 10/503 (2013.01); G01D 5/35361 (2013.01); G01D 5/35364 (2013.01); G01M 11/3109 (2013.01); H04B 10/07 (2013.01); H04B 10/60 (2013.01); H04B 10/61 (2013.01); H04B 10/614 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A channel checker optical time-domain reflectometer (OTDR) comprising:
a first laser source to emit a first laser beam;
a second laser source to emit a second laser beam;
a first photodiode to acquire a beat frequency between the first laser beam and the second laser beam, wherein the beat frequency is used to maintain a predetermined offset frequency shift between the first laser beam and the second laser beam, wherein the predetermined offset frequency shift is relative to a predetermined frequency of either the first laser beam or the second laser beam;
a modulator to modulate the first laser beam, wherein the modulated first laser beam is to be injected into a device under test (DUT);
a coherent receiver to acquire a backscattered signal from the DUT, wherein the backscattered signal results from the modulated first laser beam injected into the DUT, and wherein the coherent receiver is to determine Brillouin traces and Rayleigh traces with respect to the DUT based on the predetermined offset frequency shift between the first laser beam and the second laser beam;
a second photodiode to receive a portion of light from the second laser beam to enable detection of beat terms signals;
a tunable filter optically coupled to the second photodiode; and
a radio frequency (RF) detector optically coupled to the tunable filter, wherein the beat terms signals are selectively passed to the RF detector to detect live traffic on the DUT.