| 摘要 |
An optical system includes a substrate adapted for supporting a sample, where the substrate has a refractive index, nsub, larger than a refractive index of the sample, nsample, a source of electromagnetic radiation having wavelength, lambdao, and a detector having multiple individual detector elements configured for detecting a signal resulting from an interaction of the electromagnetic radiation with the sample. The system includes dividing optics, directing optics, and control optics. The dividing optics are configured for dividing the electromagnetic radiation from the source into at least three substantially independent excitation beams. The directing optical elements are configured for directing each excitation beam in a unique direction, kn, through the substrate and incident upon an interface between the substrate an the sample at angles relative to a normal axis to the interface, êz, such that each excitation beam is divided into a reflected beam and an evanescent interfacial beam within the sample that travels in the plane of the interface. The evanescent beams at least partially intersect with each other within at least a portion of the sample to create an excitation region with an interference pattern having a symmetry of a two dimensional interfacial Bravais lattice. The control optical elements are configured for controlling an electromagnetic field of each excitation beam such that a basis associated with the interfacial Bravais lattice includes a substantially isolated excitation maximum in each primitive cell of the lattice substantially confined to a size less than a substrate wavelength, lambdasub=lambdao/nsub, in any direction parallel to the interface, where the directions, kn, of the excitation beams are selected such that the periodicity of the lattice in any direction parallel to the interface is large enough for signals from adjacent excitation maxima to be individually resolved and simultaneously measured by separate elements within the detector.
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