Question

I understand how the pulses are created by the addition of waves with harmonic frequencies in a classical sense.

However, from a quantum mechanical point of the view, light comes as photons with quantised energy, with the energy of each photon related to its frequency. As the attosecond pulses consist of many frequencies, I wonder how they relate to photons.

My guess would be that the attosecond wave describes the probability of detecting a photon at a particular location/time, but that the photon detected can have the energy corresponding to any of the constituent frequencies.

Is that a correct guess, or is that too simplistic? When we detect individual photons of the attosecond pulse, what frequencies can they have?

Answer 1

An attosecond pulse consists of photons with discrete energies that correspond to the frequencies of waves superimposed to create the pulse. Individual photons from these pulses will have energies associated with these frequencies, exemplifying the duality of light as both waves and particles.

Step-by-step explanation:

From the perspective of quantum mechanics, attosecond pulses and the composition of photons within them can be understood by considering Planck's formula E = hf, where E is the energy of a photon, f is the frequency, and h is Planck's constant. An attosecond pulse that contains a range of frequencies will consist of photons with discrete energies corresponding to those frequencies. The relationship between the wave and particle nature of light allows for the construction of these pulse trains, which represent a superposition of different energy photons.

When we detect an individual photon from an attosecond pulse, it will have an energy corresponding to one of the frequencies of the waves that were superimposed to create the pulse. As such, a detected photon can indeed embody any of the constituent frequencies in the pulse. It is important to remember that electromagnetic waves can be modeled as a stream of photons, especially evident at high frequencies where energy quantization becomes significant.