Single Photon Experiments using Type-I and Type-II Spontaneous Parametric Downconversion

We created an optical setup that detects single photons generated using Type-I spontaneous parametric down conversion (SPDC). A laser diode creates violet 405nm photons that are split into pairs of infrared 810nm photons and are detected in coincidence using a Field Programmable Gate Array (FPGA), using programs in LabVIEW for data acquisition. We found a value of 𝑔²(0) to be 0.0014 ± 0.001, conclusively demonstrating the particle nature of light. Incorporating a Mach-Zhender interferometer will allow us to simultaneously demonstrate the wave nature through single-photon interference.