I am new to quantum mechanics and I am not much familiar with it. I have a doubt. Consider a scenario in which a photon is passed through an apparatus which is partly mirror and partly lens. The wave function of the photon is such that there is 75% chance of photon hitting the mirror thereby geting reflected back to the same side of the apparatus and 25% chance of photon hitting the lens thereby passing to the other side of the apparatus. My question is what will happen to the wave function of photon after interacting with the apparatus. Will the wave function be split in to either sides of the apparatus such that 75% of photon corresponds to one side of apparatus and 25% of photon corresponds to other side? Suppose we measure the photon after the interaction, will the photon be detected on one side of apparatus 75% of times and on the other side of apparatus 25% of times? In other words, will photon be measured to exist in different sides of the apparatus at diffeent times. If the same photon is measured after 1 year, will the photon be detected to exist at different locations which are 2 lightyears apart at different instants? Is there any misconception here? Please clarify my doubt. Thanks in advance.