Abstract: A detection system for a first specific material is provided by which an interferometer, having a reference waveguide segment and a test waveguide segment, is enhanced. The test waveguide segment carries a second capture material for specifically capturing said first specific material that may be present in a fluid specimen. Capture of the first specific material is detected by an interference pattern produced by combining coherent light beams passing through the waveguide segments. To enhance by orders of magnitude the detection limits of the test, the waveguide segments are subjected to an alternating or pulsed electrical or magnetic fields. This same signal is fed to a lock-in amplifier that is associated with computational means by which the interference pattern is interpreted. The invention further includes a waveguide system in which capture of the first specific material is detected by fluorescence.