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The Extragalactic Background Light (EBL) that spans the UV-IR band originatesfrom direct and dust-reprocessed starlight integrated over the history of theUniverse. EBL measurements are very challenging due to foreground emission likethe zodiacal light and interplanetary dust emission. Indeed, some optical/NIRdirect measurements overpredict EBL models based on galaxy counts. On the otherhand, there is some debate on possible additional components of the Optical-NIRphoton density: e.g., population-III stars, axion-photon decay, direct collapseof black holes, intra-halo light etc. Owing to the absorption of Very HighEnergy (VHE) $\gamma$ rays by interaction with EBL photons, we study theprospects of accommodating an additional population of EBL sources in theOptical-NIR band on top of the standard galaxy-count--based component. To thisaim we use 105 VHE spectra of 37 blazars with known redshifts, $0.03<z<0.94$.We correct the observed spectra for absorption by our model EBL. By requiringthe intrinsic spectra to be non-concave and with a VHE spectral index $>$1.5,we estimate, at different wavelengths, upper limits to the additional lowenergy photon fields which would contribute to the absorption of $\gamma$-rays.Considering these limits we suggest that there is room for photons from Pop IIIstars and axion-like particle (ALP) annihilation. However, these additionalhypothetical photon fields are bound to fall significantly below directpublished EBL measurements by several instruments, and therefore our limits areeither in tension or even inconsistent with such measurements.

Prospects of additional contribution at Optical-NIR band of EBL in the light of VHE spectra