| 摘要 |
FIELD: physics.SUBSTANCE: invention relates to an optical device for providing non-propagating radiation in response to incident radiation in a detection volume which has a target component in a medium, wherein at least one plane dimension (W1) of the detection volume is smaller than the diffraction limit. The diffraction limit is defined by the radiation wavelength and the medium. Non-propagating radiation is provided by structures which form an opening, wherein the least plane dimension of the opening W1 is smaller than the diffraction limit. The detection volume is provided between the structures which form an opening. The structures which form an opening further determine the greatest plane dimension of the opening W2, wherein the greatest plane dimension of the opening is greater than the diffraction limit. A source is provided for emitting a radiation beam having a wavelength, which is incident on the optical device, the direction of incidence of which is not parallel to the out-of-plane normal direction, in order to provide non-propagating radiation in the detection volume in response to radiation incident on the optical device. The plane of incidence is parallel to the greatest plane dimension of the opening.EFFECT: high excitation efficiency without the need to use higher intensity for detecting target components.13 cl, 7 dwg |
