Are gamma rays the limit of the frequency photons can attain, and if yes, why? Recalling that the Planck constant is $6.62607015 \times 10^{-34} m^2kg/s$ and taking into account the formula $E=hf$, for the energy of photons, we can rapidly derive the energy of gamma rays, which have wavelength $\lambda=100\times 10^{-12}$m and thus with frequency ($f=\frac{c}{\lambda})$ of $1\times10^{19}$ Hz for gamma rays. We get the energy
$E=1\times 10^{19}\cdot6.62607015  \times 10^{-34}=6.62607015 \times 10^{-15}$J.
But what makes gamma ray the limit of electromagnetic radiation? Why is there no light which carries for instance  $1.3^{-12}$J and have a frequency of $20\times10^{20}$ Hz?
Which Universal factor imposes this limit of electromagnetic radiation, and what is it called?
 A: 
Which Universal factor imposes this limit of electromagnetic radiation, and what is it called?

In the table here for the electromagnetic spectrum the energy of  a gamma rays is given in megahertz limiting the photons to 1.24 Mev,this comes from the photons of nuclear reactions. In elementary particle physics we call gamma rays the photons decaying from the Higgs, and their energy is over 60 GeV.
So it is a matter of the ability of the technology  to detect the photons that is the  limit.
A: Gamma rays doesn't impose any frequency limit as per definition, because gamma rays just means electromagnetic waves which have frequency $\gt 10^{18}~\text{Hz}$. Upper frequency limit is imposed by Plank Units,- in this case,- Plank frequency which is:
$$
f_{p}={\frac {c}{l_{\text{P}}}}={\sqrt {\frac {c^{5}}{\hbar G}}} \approx 1.8 \times 10^{43}~\text{Hz}
$$
There can't be higher oscillations of fields, because in that case that would break universal speed limit $c$, as per $c=\lambda_{min} ~f_{max}$.
