Fiber optic security system

An optical security system which comprises:

• an optical fiber having a first end and a second end;
• an emitter optically connected to said first end;
• a detector optically connected to said second end;
• means for generating a signal for triggering said emitter and said detector, said emitter being triggered by said generating means to transmit a pulse having at lease one identifiable characteristic into said first end of said optical fiber, and said detector being simultaneously triggered by said generating means to receive said pulse as said pulse is transmitted from said second end of said optical fiber;
• means for comparing said pulse received by said detector with a predetermined reference to provide an output for adjusting said emitter to conform a subsequent said pulse to said reference;
• and
• means for monitoring said characteristic of said pulse received by said detector to alarm said system when said received pulse passes a predetermined threshold.