An apparatus for single analyte molecule detection includes: a light source (20) for generating excitation light; a dichroic mirror (22) disposed on a first path of excitation light generated by the light source, wherein the mirror directs excitation light into a fiber aligner (30); an optical transducer coupled to the light source by the fiber aligner, the optical transducer comprising an optical waveguide (40) made of dielectric material having a first dielectrical index; a photon detector (70) disposed to receive fluorescent back radiation, wherein when a test solution having a second dielectric index lower than the first index is provided and comprises one or more target molecules, excitation light is transmitted by the waveguide and exits a waveguide tip disposed in the test solution so as to excite one or more target molecules; subsequently, the waveguide transmits back radiation along a second path to the photon detector that detects the transmitted back radiation.