Multispectral characterization of diffractive micromirror arrays

Abstract

The present article discusses an optical concept for the characterization of diffractive micromirror arrays (MMAs) within an extended wavelength range from the deep ultra-violet up to near-infrared. The task derives from the development of a novel class of MMAs that will support programmable diffractive properties between 240 nm and 800 nm. The article illustrates aspects of the achromatic system design that comprises the reflective beam homogenization with divergence control and coherence management for an appropriate MMA illumination as well as the transfer of phase modulating MMA patterns into intensity profiles for contrast imaging. Contrast measurements and grey scale imaging demonstrate the operation of the characterization system and reflect the encouraging start of technology development for multispectral, diffractive MMAs

Calibration of diffractive micromirror arrays for microscopy applications

“…Full component control and synchronization allows device research and illumination pattern characterization close to application conditions. More setup details are described in [7].…”

“…The main arguments are properties like real-time grayscale imaging at high-speed as well as high contrast operation within an extended wavelength range. Previously, some of these properties have been analyzed with focus on device technology and optical characterization [6], [7]. The present paper studies the steps, necessary to achieve the high contrast capabilities of a programmable, diffractive light modulator.…”

Technology development of diffractive micromirror arrays for the deep ultraviolet to the near infrared spectral range

“…To illustrate the capabilities and potential of the developed technology, the contrast of non-calibrated MMAs has been measured. Using a green solid-state laser with a wavelength of 532 nm, an image contrast in excess of 330 has been achieved without calibration ( Figure 11, details will be published in [9]). Higher contrast values are expected after calibration of MMA's.…”

Analog Spatial Light Modulators Based on Micromirror Arrays

“…However, this setup uses mirrors instead of lenses so that light sources of significantly different wavelengths can be used; see [ 30 ]. With this setup, it has been possible not only to measure characteristics like contrast [ 32 ], but also to calibrate the mirrors using their optical behavior. This has the advantage that not only effects caused by inaccurate deflection are corrected, but also errors caused by planarity or slits can be compensated to some extent.…”