First Solar Images Using a Photon Sieve
Through the primary mirrors of today’s space observatories, the world has gained much knowledge about the universe we live in. However, looking towards a future of higher resolution imaging in space, these rigid optical elements have the drawback that they are restricted in size by the weight capacity and dimensions of the spacecrafts available. A type of diffractive optic called a photon sieve may provide an innovative alternative to these rigid optics. A photon sieve is a flat surface containing holes of various sizes to resemble the pattern of a Fresnel zone plate which focuses light of different wavelengths at different focal lengths. Since photon sieves are made on a two-dimensional plane rather than a curved surface, they can be produced on membranes that can be folded up for condensed storage within a smaller spacecraft element than is possible for rigid optics. Prior to sending this new technology up into space for solar imaging, verification of functionality on earth must take place first through a ground test of a photon sieve optical system, which is the project I worked on this past summer at NASA Goddard Space Flight Center with mentors Adrian Daw and Douglas Rabin as well as summer intern Laura Dunlap. The optical system we created uses a 56.16 mm diameter photon sieve on a chrome-coated quartz plate with 1500 Fresnel zones containing over 15 million holes. It is designed to take images of the Sun that are limited to wavelength H-alpha. During the final week of our internship, we mounted the system onto a telescope and took the first images of the Sun using a photon sieve. Having determined the functionality of the system, the resolution of the system as well as other versions of photon sieves will be investigated so that this technology can next be used in space where the benefits of the ability to use a large, lightweight primary optic can be fully utilized to study the Sun’s features at high resolution.
Vievering, Juliana T., "First Solar Images Using a Photon Sieve" (2012). Physics Student Work. 2.