PolyOculus

UCF Astrophotonics Lab · CREOL

Aperture is expensive. The cost of a conventional telescope rises steeply with mirror diameter, which is what makes very large single-aperture instruments so rare. PolyOculus takes the other route: link many low-cost, commercially available telescopes together with optical fibre so the array behaves as one much larger collecting area.

Bar chart of cost per square metre of collecting area against telescope diameter. Standard telescopes range from 1.3 to 1.7 million dollars per square metre across 1 m to 30 m apertures, while PolyOculus ranges from 150,000 dollars at 1 m down to 100,000 dollars at 8 m and 30 m. — Cost per square metre of collecting area, PolyOculus against conventional telescopes. The advantage widens with aperture. Figure: PolyOculus programme, CREOL.

The science case

The array's driver is a redshift drift experiment — watching absorption features in the spectra of high-redshift quasars shift over time, a direct measurement of cosmic acceleration rather than an inferred one. That needs an enormous amount of collected light and an extremely stable spectrograph, fed through photonic linkage and calibrated against a laser frequency comb.

Concept diagram of the redshift drift experiment: light from a high-redshift quasar is collected by a low-cost array of autonomous commercial telescopes, carried by photonic linkage to an ultra-stable spectrograph calibrated with a laser frequency comb, producing a spectrum with hydrogen absorption and emission features and metal absorption lines. — The redshift drift concept — array, photonic linkage, frequency-comb calibration, and the resulting quasar spectrum. Figure: PolyOculus programme, CREOL.

What I work on

I contribute mount control and pointing automation for the array. An array only pays off if every telescope in it acquires and tracks its target without someone standing at each one, so the pointing has to be reliable and hands-off across the whole set.