According to one embodiment, a method includes receiving a first optical signal at a pulse detector. An electronic pulse of the first optical signal is received at an optical module. A second optical signal is generated at the optical module based on the electronic pulse. At least a portion of the first optical signal is received in a reverse direction at an optical isolator and the second optical signal is received in a forward direction at the optical isolator. The optical isolator substantially transmits the second optical signal to a target in the forward direction. The optical isolator substantially attenuates at least a portion of the first optical signal in the reverse direction.