Hypothetical maximum energy of a single photon

Question

I'm no physicist so it might be a stupid question but is there a maximum energy a single photon can have?

My idea was, that there might be restriction for the minimum wavelength and I thought about the Planck length: $1.616 · 10^{−35}$ m

So my hypothetical photons energy would be:

$$E=hf=\frac{hc}{\lambda}$$

So I put the values inside: $$E=\frac{6.62607015 \cdot 10^{−34}\cdot 299792458}{1.616 \cdot 10^{−35}} \frac{\text {J s m}}{\text{s m}}$$

which gives me the value: $1.23*10^{10}$ J

Is this the maximum amount of energy that a single photon can have, or is the concept of using the planck length as minimal possible wavelength not correct?

And are photons with that much energy even existing in the universe?

Answer 1

We have no evidence for Planck-energy particles. The highest-energy cosmic-ray particle ever detected (which was probably a proton) carried 51 J, more than a billion times less. The highest-energy photons ever detected carry only nanojoules, another factor of a billion down the energy scale.

We don’t understand physics at the Planck scale, so we don’t know whether smaller lengths and higher energies are possible or not. But particles with Planck energies do not appear to be zipping around our universe, which is a good thing!

Answer 2

Using the Planck length as a cutoff makes sense because we are still not able to predict consistently what happens at higher energies.

This does not mean that you cannot have a "bigger" quantum of energy, e.g. a photon of higher energy. Sure if you have it, you would also have very non trivial quantum-gravitational effects.

To my knowledge there is no proof against the possibility of such photon. But maybe some approach to quantum gravity could offer an argument against it.