I am trying to establish a model inside my head of how light behaves but find it hard with all the seemingly contradicting information.
For example, electrons inside a Laser are raised to a higher energetic state and consequently emit photons of a specific wavelength when falling back to their ground state.
Am i not supposed to think of a photon created in such a process as traveling in all possible directions, with the wave function giving me the probability of finding that photon in a specific volume of space at a given time-interval?
In the above description, photons do not have any specific direction at all. So i would like to ask if we can create a single photon in a vacuum which then travels in a specific direction?
If not, then is the direction of a photon merely an "illusion" created by overlapping wave functions which result in a very low probabilities to find a photon in certain volumes of space?
When photons exit a laser, can i treat them as single photons, hence, imagine the wave-function for each photon extending in all directions in space, then overlap all wave-functions of every photon and calculate the probabilities of finding a photon in a certain volume of space at a given time-interval or is there more going on i have to account for? Because i cannot see why a laser beam would stay so focused for such long distances just by the cancellation of waves in all directions other than the direction the laser is pointing towards. Would a single photon exiting the laser have any higher probability to be found on the straight line the laser is pointing towards later than in any other direction? If yes, why?
I hope that someone can help me to create a better model inside my head of how light really works.