a laser source configured to propagate a laser beam;

a memory comprising executable instructions;

a processor in data communication with the memory and configured to execute the instructions, which cause the processor to control the laser source based on a detection signal received from a circuit, the circuit comprising:

a first amplifier having an output coupled to an input of a first comparator and an input of a second amplifier;

a switch coupled between the input of the second amplifier and a reference potential node, wherein a state of the switch is controlled based on an output of the first comparator;

a second comparator having an input coupled to an output of the second amplifier, wherein the first comparator has a first threshold voltage which is greater than a second threshold voltage of the second comparator; and

a logic gate having a first input coupled to an output of the first comparator and a second input coupled to an output of the second comparator, wherein an output of the logic gate is the detection signal; and

a lens configured to focus the laser beam onto an interface plane of a proximal end of an optical fiber coupled to the surgical laser system through a port, wherein a distal end of the optical fiber is configured to project the laser beam onto a target surface.