This lecture covers the fundamentals of wave optics, including the transition from ray optics, the contributions of Huygens and Young, wave functions, wave propagation in different media, the spectrum of solar radiation, optical intensity, power, and energy, monochromatic and complex wave functions, interference of waves, examples of interference, interferometers like Michelson and LIGO, ultrafast spectroscopy, optical beating, and pulsed light description.