Optical characterisation and analysis of multi-mode pixels for use in future far infrared telescopes

The lunar surface allows a unique way forward in cosmology, to go beyond current limits. The far side provides an unexcelled radio-quiet environment for probing the dark ages via 21 cm interferometry to seek elusive clues on the nature of the infinitesimal fluctuations that seeded galaxy formation. Far-infrared telescopes in cold and dark lunar polar craters will probe back to the first months of the Big Bang and study associated spectral distortions in the CMB. Optical and IR megatelescopes will image the first star clusters in the Universe and seek biosignatures in the atmospheres of unprecedented numbers of nearby habitable zone exoplanets. The goals are compelling and a stable lunar platform will enable construction of telescopes that can access trillions of modes in the sky, providing the key to exploration of our cosmic origins. This article is part of a discussion meeting issue ‘Astronomy from the Moon: the next decades’.

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Multi-mode light microscopy of microtubule assembly dynamics and chromosome movement in vivo and In vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166117 ◽

1996 ◽

Vol 54 ◽

pp. 730-731

Author(s):

E. D. Salmon ◽

J. C. Waters ◽

C. Waterman-Storer

Keyword(s):

Imaging System ◽

Ccd Camera ◽

Transmitted Light ◽

Microtubule Assembly ◽

Live Cells ◽

Optical Efficiency ◽

Multiple Band ◽

Multi Mode

We have developed a multi-mode digital imaging system which acquires images with a cooled CCD camera (Figure 1). A multiple band pass dichromatic mirror and robotically controlled filter wheels provide wavelength selection for epi-fluorescence. Shutters select illumination either by epi-fluorescence or by transmitted light for phase contrast or DIC. Many of our experiments involve investigations of spindle assembly dynamics and chromosome movements in live cells or unfixed reconstituted preparations in vitro in which photodamage and phototoxicity are major concerns. As a consequence, a major factor in the design was optical efficiency: achieving the highest image quality with the least number of illumination photons. This principle applies to both epi-fluorescence and transmitted light imaging modes. In living cells and extracts, microtubules are visualized using X-rhodamine labeled tubulin. Photoactivation of C2CF-fluorescein labeled tubulin is used to locally mark microtubules in studies of microtubule dynamics and translocation. Chromosomes are labeled with DAPI or Hoechst DNA intercalating dyes.

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