US 11,757,533 B2
Shutdown circuitry for a laser emitter
Mikhail Dolganov, Gilroy, CA (US); Lijun Zhu, Dublin, CA (US); and Hao Huang, San Jose, CA (US)
Assigned to Lumentum Operations LLC, San Jose, CA (US)
Filed by Lumentum Operations LLC, San Jose, CA (US)
Filed on Sep. 28, 2021, as Appl. No. 17/449,164.
Claims priority of provisional application 63/260,261, filed on Aug. 13, 2021.
Prior Publication US 2023/0046942 A1, Feb. 16, 2023
Int. Cl. H04B 10/564 (2013.01); H04B 10/50 (2013.01)
CPC H04B 10/564 (2013.01) [H04B 10/504 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An optical device, comprising:
an optical element;
a laser emitter configured to emit light via the optical element;
at least one of:
a photodiode electrically connected to a shutdown circuit and configured to output a first signal based on light emitted by the laser emitter and reflected from the optical element, or
a conductive path disposed on the optical element and electrically connected to the shutdown circuit, and configured to output a second signal based on a continuity of the conductive path; and
the shutdown circuit, comprising:
at least one of:
a first comparator for comparing the first signal and a first threshold voltage, or
a second comparator for comparing the second signal and a second threshold voltage;
a filter for receiving a laser trigger signal for the laser emitter, the filter configured to output a filtered signal in which individual pulses of the laser trigger signal are removed;
a logic gate configured to receive the filtered signal and an output of at least one of the first comparator or the second comparator;
a flip-flop configured to receive an output of the logic gate and to output an enablement signal for the laser emitter that is based on the output of the logic gate;
a switch configured to control current flow to the laser emitter based on the laser trigger signal; and
a driver circuit for the switch, the driver circuit configured to receive the enablement signal and the laser trigger signal and to output the laser trigger signal based on whether the enablement signal is a first voltage or a second voltage.