Abstract: The invention discloses a luminescence sensor for bio-sensing having an input reflector and an output reflector. The gap between the input and output reflectors constitutes an optical cavity. One or both of the input and output reflectors can be a wire-grid polarizer having apertures, where at least one dimension of the apertures is below the diffraction limit. When input radiation impinges the input reflector a fraction of the input radiation is transmitted into the cavity. The energy of the radiation inside the cavity is increased due to the resonance properties of the cavity. Due to the increase of the cavity excitation energy, the luminescent radiation emitted from the luminescent particles inside the cavity can be detected outside the cavity. Since the input and output reflectors have high reflection coefficients the input radiation is effectively prohibited from being transmitted through the luminescence detector.

Abstract: The invention discloses a luminescence sensor (101) for bio-sensing having an input reflector (253) and an output reflector (254). The gap (S) between the input and output reflectors constitutes an optical cavity. One or both of the input and output reflectors can be a wire-grid (270) having apertures (211,212), where at least one dimension of the apertures is below the diffraction limit. When input radiation (221) impinges the input reflector a fraction of the input radiation is transmitted into the cavity. The energy of the radiation inside the cavity is increased due to the resonance properties of the cavity. Due to the increase of the cavity excitation energy, the luminescent radiation emitted from the luminescent particles inside the cavity can be detected outside the cavity. Since the input and output reflectors have high reflection coefficients the input radiation is effectively prohibited from being transmitted through the luminescence detector.