Dragonfly sets sights on distant planets
Wurrumbugle NP, location of the Anglo-Australian Telescope
A team from CUDOS, the Australian Astronomical Observatory and Sydney Institute for Astronomy successfully installed Dragonfly, a single hybridized photonic chip designed to take images of distant planets, at Australia’s largest telescope.
Lead by Dr Nick Cvetojevic, the team travelled to the Anglo-Australian Telescope, near the remote NSW town of Coonabarabran, to install and test the new instrument over four nights in July 2015.
Dragonfly removes the effect of turbulence in the atmosphere by a form of interferometry called aperture masking, which allows astronomers to take accurate images of distant planets. Dr Cvetojevic said that interferometry has traditionally been done by bulk optics, but the method faced limitations due to its sensitivity to misalignment and poor throughput.
“Dragonfly replaces bulk optics by containing the entire instrument on a chip that combines 3D direct laser-written and lithographic photonic platforms,” said Dr Cvetojevic. “The challenge was to get light from the telescope into photonics of this kind”.
To overcome this, the team developed a new telescope module (Adaptive Injection) that enables unprecedented levels of coupling. It is capable of correcting any misalignment between the telescope and photonics at high speeds using a micro-electromechanical segmented mirror (looping at 500 times a second), ensuring that all the light from the four-metre telescope mirror is focused on the microscopic waveguide cores that make up Dragonfly.
The team will return to the observatory in November to begin surveying nearby stars for faint companions and exoplanets.
Deploying Dragonfly on the Anglo-Australian Telescope
Dr Arriola (MQ CUDOS) and Dr Cvetojevic (CUDOS/AAO) installing the Dragonfly instrument at the base of the telescope.
The Dragonfly Interferometer chipset.