From the Hanbury-Brown&Twiss Experiment to Ghost Imaging and Ghost Spectroscopy with Superluminescent Diodes
Istituto Nazionale di Ricerca Metrologica (INRIM)
Cinference Room, Building M
Institute of Applied Physics
Technische Universität Darmstadt (Germany)
Sixty years ago, the Hanbury-Brown Twiss (HBT) experiment has been conceived by Robert Hanbury Brown and Robert Quentin Twiss in various versions, beginning in 1954 with the radio-astronomical version  via the optical one applied to Sirius in 1956 leading finally to the terrestrial one in 1956 The Hanbury-Brown & Twiss experiment has been originally motivated by the request for determining the angular diameter of stars with unprecedented stability by measuring intensity correlations instead of field correlations. We review this experiment with its tremendous outreach into nowadays quantum optics research, an experiment having been fundamental in the spirit of quantum optics at a time even before the 1st laser existed. Within the framework of the terrestrial version in 1956 from nowadays 61 years ago, the discovery of photon bunching, the quantum nature of light emitted by a thermal source has founded modern quantum optics.
In the spirit of the HBT experiment, we show comprehensive investigations of the second order coherence properties of broadband amplified spontaneous emission (ASE) light generated by semiconductor-based opto-electronic quantum dot SLDs and demonstrate that they exhibit perfect photon bunching with a normalized 2nd order correlation coefficient of two, thus with a Bose-Einstein photon statistics of a thermal source.
Then, we conceive and realize a ghost imaging (GI) experiment with Amplified Spontaneous Emission (ASE) light emitted by a Broad-Area SLD and discuss its performances. In close analogy to the exploitation of spatial correlations in GI, we then proceed in exploiting the spectral correlations of broadband light emitted by an SLD and realize the first ghost spectroscopy experiment with an optoelectronic superluminescent diode by measuring the absorption feature of chloroform at 1300nm and discuss finally its ideas, functionalities and applications.