Greg Matloff and his wife, C Bangs, have researched the use of holographic films for solar and laser pushed space sails. Matloff’s work is described at Centauri Dreams.
Greg Matloff is on the Advisor’s Board of Yuri Milner’s $100 million Breakthrough Starshot project. Matloff has worked for decades interstellar travel techniques.
Breakthrough starshot is considering a roadmap to get to a 50-70 GW laser array mounted atop a southern hemisphere mountain would generate a beam that would be projected against an Earth orbiting ~1 m photon sail for a period of minutes. The sail would be a major component of a ~1 gram wafer-scale spacecraft with a ~0.1-gram payload that would exit the beam after experiencing average accelerations of ~5,000 g. The planned interstellar cruise velocity of the tiny spacecraft is ~0.2c and the voyage time to the Proxima/Alpha Centauri system is approximately two decades.
The art and science of holography has advanced at a rapid pace during the past few decades. Holograms as thin as 25 nanometers have been produced by an Australian-Chinese team. Highly efficient wavelength-selective holographic filters and reflectors have been produced and evaluated. Some modern holograms contain 10,000 holographic layers.
It no longer seems impossible to Matloff that the Project Starshot goals can be achieved. One would use a holographic film and expose the image of a filter or mirror that is highly reflective in the laser’s wavelength range. Matloff’s colleague at Citytech, Lufeng Leng teaches optics. She is quite sure that a hologram of a spherical surface will behave optically like a spherical surface. So the filter or mirror should ideally have a convex spherical shape, from the point of view of the observer (or laser).
Pissing in the interstellar wind. Dead on arrival. To read more, click here.