Mid Term Review

Chalcogenide glass photonic chips for exoplanet hunting in the mid-infrared

Mr Harry-Dean Kenchington Goldsmith
Laser Physics Centre, RSPE, ANU

Planets outside of our solar system are hard to find and even harder to image. Most methods for discovering other worlds are indirect measurements, a shadow across a sun or a large, measurable, gravitational influence, but few extra-solar planets have been imaged directly. The challenge is to suppress the vastly brighter star light to enable the planet to be seen. One very promising approach for star light suppression is to use interference to recombine light from multiple sources to null the star but form an image of the planet. Photonic chips offer significant advantages for interferometry due to the inherent mechanical and thermal stability of all interfering paths. However, forming exoplanets are found in dust clouds necessitating the use of the mid-infrared part of the spectrum to penetrate the dust veil, and mid-infrared photonic chip technology and devices are much less well developed than their near-infrared counterparts. Using Chalcogenide glass, highly fabrication tolerant high performance beam combiners have been designed and preliminary measurements performed that provide a viable path to a device for on-sky application. In the future, this technology will enable researchers to null starlight from a central star and image the planets around it to distances less than one earth orbit from the star.

Date & time

Mon 31 Jul 2017, 3–4.30pm



RSPE Seminar Room


Members of RSPE welcome