A novel telescope architecture is proposed specifically for the purpose of taking spectra of exoplanets orbiting stars within 10 pc ("the neighborhood"). The primary objective and the secondary spectrograph are holographic optical elements (HOEs) formed on flat membrane substrates of low areal mass that can be transported on cylinder rolls that are compatible with the payload geometry of delivery vehicles. Ribbon-shaped HOEs of up to 100 x 10 meters are contemplated. Computer models are presented with these dimensions. The models predict resolving power better than 10 mas. Because the primary separates wavelengths, we consider coronagraphs that use the divide and conquer strategy of one wavelength at a time. After delivery at the second Lagrange point, the stowed membranes are unfurled into flat holographic optics positioned in a four part formation spanning 1 km of open space.
This paper discusses progress toward development of a high- speed holographic printer, the Holocomposer, suitable for producing identification cards containing miniature holographic portraits. It is believed that a holographic portrait of the bearer of a card cannot be altered or counterfeited at a cost low enough to justify the counterfeiter's risk of discovery.
A brief survey of simple hologram counterfeiting techniques
and appropriate countermeasures is given and specific cases of
successful and unsuccessful counterfeiting attempts are discussed.
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