  The Hanbury Brown-Twiss (HBT) effect holds a pivotal place in intensity
interferometry and gave a seminal contribution to the development of quantum
optics. To observe such an effect, both good spectral and timing resolutions
are necessary. Most often, the HBT effect is observed for a single frequency at
a time, due to limitations in dealing with multifrequencies simultaneously,
halting and limiting some applications. Here, we report a fast and data-driven
spectrometer built with a one-dimensional array of single-photon-sensitive
avalanche diodes. We report observing the HBT effect for multifrequencies at
the same time. Specifically, we observed the HBT for up to 5 lines of the Ne
spectrum, but this can be improved even further. Our work represents a major
step to make spectral binning and multifrequencies HBT more widely available.
The technology we present can benefit both classical and quantum applications.
