Resolution of subwavelength-spaced scatterers by superdirective data processing simulating evanescent wave illumination

Information concerning the subwavelength structure of an object is normally irretrievable from its radiated spatial-frequency distribution: consequently such fine detail is classically irresolvable. It is shown that supcrdirectivc data processing may be used to extrapolate beyond the visible spatial-frequency range so that the individual wires in an array of three 0-6 ¿¿-spaced wire scatterers are resolved. A new development of this technique, based on synthetic evanescent-wave illumination, aids recovery of extrapolated spatial frequencies which subsequently provide even greater resolution.