Direct measurement of pseudothermal light violating Siegert relation
Xi Jie Yeo, Justin Yu Xiang Peh, Darren Ming Zhi Koh, Mingze Qing, Jaesuk Hwang, Peng Kian Tan, Christian Kurtsiefer · 2024
Pseudothermal light exhibits photon bunching, like thermal light, but it does not originate from randomly phased emission. As photon bunching is common in both pseudothermal and thermal light, the analysis of photon bunching is insufficient to differentiate pseudothermal light and thermal light. However, thermal light obeys the Siegert relation, which connects the interferometric visibility ∥g(1)(τ )∥ and second-order photon correlation g(2)(τ ). In this work, we present a direct test test for Siegert relation by a single-shot measurement. Using our technique, we demonstrate that laser light scattered off a rotating ground glass, violates the Siegert relation, which provides further evidence that it is a pseudothermal light source.