Generation of achromatic and propagation-invariant spot arrays by use of continuously self-imaging gratings

Abstract

A particular class of Montgomery's self-imaging objects that we call continuously self-imaging gratings (CSIG's) is introduced. When they are illuminated by a plane wave, these objects produce a field whose intensity profile is a propagation- and wavelength-invariant biperiodic array of bright spots. The mathematical construction of these objects and their intrinsic properties are described. On a practical level, CSIG's are compact and achromatic nondiffracting array generators. We show that a good CSIG approximation can be realized by a two-level phase grating that is experimentally tested.

Intrapixel measurement techniques on large focal plane arrays for astronomical applications: a comparative study

“…Schematic representation of the principle of the test bench The CSIG is a diffractive element, a complete description of its properties can be found in [21]. Depending on the substrate material, different CSIGs can be manufactured to cover the visible, the near-infrared and the long-wave infrared bands.…”

Experimental Performance and Monte Carlo Modeling of Long Wavelength Infrared Mercury Cadmium Telluride Avalanche Photodiodes

“…[19][20][21][22] As LWIR e-APD focal plane arrays have no readout integrated circuits (ROICs), direct acquisition of the interferogram image was replaced by a 2D displacement (x and y) of the continuously self-imaging grating in front of the pixel using two linear stages. The high background photocurrent was another major difficulty of this measurement.…”

Nonparaxial analysis of continuous self-imaging gratings in oblique illumination

“…1). The intersection of the horizontal and vertical grid lines with the circle form a set of points that can be called "orders" (see [15]), as they constitute the set of orders of any bidimensional grating of pitch a 0 in both x and y directions. The different orders selected have the following coordinates in the spatialfrequency domain:…”

“…We studied experimentally a CSIG with the characteristics [ 2 = 650, a 0 = 1000 m] and placed at a distance of 30 mm from the detector. The grating used for this experiment is a two-level approximation of the ideal transmittance as described in [15]. It is a binary-phase grating on a GaAs substrate.…”

“…Studies in [10][11][12][13] on the tolerance in angles of axicons have suggested that they are very sensitive to off-axis aberrations, but this needs further investigation. The purpose of this paper is indeed to study the tolerance angle of a particular class of optical components called continuously self-imaging gratings (CSIGs) [14,15]. These components have similarities with axicons in terms of depth of focus and resolution.…”