Patent ID: 6552864
Filing Date: 2003-04-22
Classification: G02B

Abstract:
A method for generating a radiation pattern in a target plane located in a near-field region of a radiation emitting system and at a desired distance from said radiation emitting system, the method comprising the steps of:a) emitting a beam of radiation; b) producing from said emitted beam of radiation a propagating radiation pattern propagating through a first medium of a refraction index n1; c) directing the propagating radiation pattern from said first medium onto said target plane located in a second medium having a refraction index n2, where n21, said radiation having a wave number k defined by 2&pgr;/&lgr; where &lgr; is the wavelength of said radiation in said second medium, wherein said propagating radiation pattern is produced in such a manner that substantially all spatial frequency components y of a resulting field of said propagating radiation pattern are greater than said wave number k such that said propagating radiation pattern generates a focused evanescent radiation pattern at said target plate with substantially zero propagating components within said second medium.