Hello everyone, I have a question that I don't understand in the laser operation: how many transverse modes does the single frequency laser have and how many longitudinal modes does multimode laser have? Well, when i started the search for this question there were no straight answer, but as i get it: single frequency laser means also single mode if actually I can say it, so, single frequency laser has 1 trasverse mode and 1 longitudinal mode, hasn't it? And also about multimode: it has N longitudinal modes due to the number of transverse mode, isn't it? I also tried to draw the frequency spectra of single frequency laser as I understood the material.