Research of balanced detection techniques for high speed weak optical signal

Long-distance high speed weak photoelectric detection technology is widely used in laser communication. To detect the weak signal which is not buried in the noisy environment, balanced detection technology becomes more and more important. Single pipe coherent detection and balanced coherent detection were compared firstly. After theoretical analysis and numerical simulation, signal-to-noise ratio of the balanced detection was greatly superior to that of the single tube detection when the consistency coefficient was bigger than 0.6. The minimum detectable optical power of the single tube detection and balanced detection was analyzed. The results prove the superiority of balanced detection technology used in high speed weak optical signal detection.