Bulk plasmons are collective oscillations of free electrons in a material, typically found in metals. These oscillations occur when light interacts with the electron gas, leading to a wave-like motion of the electrons. This phenomenon is significant in understanding how materials respond to electromagnetic fields, particularly in the context of plasmonics. In bulk materials, plasmons can propagate over longer distances compared to surface plasmons, which are confined to the surface of a material. The study of bulk plasmons is important for applications in nanotechnology and optical devices, where controlling light at the nanoscale can enhance performance and functionality.