Writing arbitrary distributions of radiant exposure by scanning a single illuminated spatially random screen

Abstract

Arbitrary distributions of radiant exposure may be written by transversely scanning a single known spatially-random screen that is normally illuminated by spatially but not necessarily temporally uniform radiation or matter wave fields. The arbitrariness, of the written pattern of radiant exposure, holds up to both (i) a spatial resolution that is dictated by the characteristic transverse length scale of the illuminated spatially random screen, and (ii) a background term that grows linearly with the number of random-illumination patterns. Two classes of the method are developed. The former assumes the distance between the illuminated random mask and the target plane to be sufficiently small that the effects of diffraction may be neglected. The latter accounts for the effects of Fresnel diffraction in the regime of large Fresnel number. Numerical simulations are provided for both variants of the method. Contrast and signal-to-noise ratio are also considered. The method may be parallelized, and is suited to both magnifying and de-magnifying geometries. Possible applications include spatial light modulators and intensity projectors for those matter and radiation wave fields for which such devices do not exist, printing or micro-fabrication in both two and three spatial dimensions, and lithography.

On the Inherent Dose-Reduction Potential of Classical Ghost Imaging

“…This is a generalization of the finding in Ref. [41] for binary images that SNR is inversely proportional to the square-root of the number of non-zero elements; for binary images µ 2 T + σ 2 T = µ T . We note that this analysis of the adjoint operation provides an estimate of the lower limit on SNR.…”

Sharp images from diffuse beams: factorisation of the discrete delta function

“…III, where we also describe an exact multiplex-demultiplex imaging strategy for demodulating the measured intensity from a sample signal of interest. Note that a precisely analogous approach may also be employed for diffuse-probe lithography [53].…”

Ghost projection. II. Beam shaping using realistic spatially-random masks

“…This notion underpins both classical ghost imaging [1][2][3] and random-basis decomposition [4], which leads to the related idea of ghost projection [5]. The key concept is that an ensemble of spatially-random masks may be illuminated, with uniform or non-uniform exposure times, to generate an arbitrary desired spatial distribution of radiant exposure [5,6]. The arbitrariness of the resulting spatial distribution is limited by the highest spatial frequencies in the illuminated masks, and a constant additive offset or pedestal.…”

“…The ensemble of illuminated random masks may be generated by transversely scanning a single random mask [6]. A single non-random mask may also be employed, e.g.…”

“…The bucket signals can be correlated with the known masks, to reconstruct the transmission function of the sample. Conversely, ghost projection creates a desired timeintegrated transmission pattern by sequentially illuminating a set of suitable masks [5,6]. Here, the mask exposure times are analogous to bucket signals.…”