Patent ID: 7912369

Claim:
A method comprising: transmitting one or more optical information signals from a first element to at least a second element; receiving, by a third element, wherein the first element is between the second and third elements, one or more reflected optical information signals attributable in at least part to one or more reflection characteristics of the second element; generating the optical information signals by a fourth element, wherein the first element is between the second and fourth elements; converting the reflected optical information signals into one or more electrical trigger signals; and terminating the optical information signals if at least one electrical trigger signal converted from said reflected optical information signals is equal to or greater than a first threshold value; wherein the terminating the optical signals comprises terminating the optical signals by a fifth element that is powered by the electrical trigger signal converted from said reflected optical information signals when the at least one electrical trigger signal converted from said reflected optical information signals is equal to or greater than the first threshold value.