Compact tunable hyperspectral imaging system

Abstract

We present a compact hyperspectral imaging system consisting of a combined refractive-diffractive optical element for extended longitudinal chromatic aberration, which provides spectrally resolved information of an object. This fully integrated hybrid device features a diffractive optical element (DOE) acting as a positive lens, a tunable concave liquid-filled membrane lens, and integrated magnetic actuation for hydraulically tuning the focal length of the membrane lens. The lens system is demonstrated to generate a hyperspectral data cube in the visible wavelength range by imaging the light from a pinhole array in a confocal approach onto a CCD camera.

Linear micromechanical stepping drive for pinhole array positioning

“…In this paper an electrostatic stepper drive is presented to enhance the imaging quality of a novel pinhole-based hyperspectral optical system [1][2][3][4][5]. To enable the further miniaturization of the imaging system, a micromechanical solution is preferred.…”

“…By selecting and evaluating the CCD pixels at the sharp image points and tuning the focal length of the hyperchromatic optics, a hyperspectral image can be captured. For a more detailed description of the optical system see [1][2][3][4][5].…”

2D stepping drive for hyperspectral systems

“…analysis of blend homogeneity of pharmaceutical products [2] or remote sensing in agriculture [3]. A novel HSI system based on the confocal chromatic principle enables imaging with high spatial and high spectral resolution [4][5][6][7] at a compact size. By using hyperchromatic lenses in combination with a movable pinhole array which is a rectangular matrix of small (20-40 µm) circular apertures, complete images for different spectral bands can be recorded (see figure 1).…”