Speaker
Description
Recent developments in single-photon avalanche diodes (SPADs) have lowered detector time resolution to under tens of picoseconds full width half maximum (FWHM). In 1956, the pioneer experiment of Hanbury Brown and Twiss (HBT) on measuring the sizes of bright stars was limited by the time resolution of their detectors and their telescope size. The QUASAR project aims at building SPAD-based multichannel intensity interferometer to be installed on large optical telescopes with kilometers-long baselines, improving the S/N obtained by Hanbury Brown and Twiss by one million and aiming to reach EHT like resolution but in visible light.
In this work we report the results of laboratory test of SPAD detectors to observe the HBT effect in photon-counting mode. Using a simple laboratory setup, and cutting edge SPAD detectors we deduce a time accuracy of <50ps FWHM. Additionally, using thermal sources and narrow spectral filters we analyze the second order correlation function obtained from different light sources of continuous and lined spectrum. Results are discussed and compared with quantum optic models. Furthermore, we report on a setup, allowing to simulate and estimate the size of an artificial star of known size to verify the analysis and data correlation techniques employed in QUASAR project.
| Collaboration(s) | QUASAR project |
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