This physical phenomenon is called radioactivity.
The laser causes the stimulated emission of radiation. The light emitted is monochromatic and coherent,that is plane polarised. I imagine that spontaneous emission occurs in a Light emitting diode ,monochromatic but not polarised. Hope this is of help
Spontaneous emission occurs randomly and naturally when an excited atom transitions to a lower energy state, releasing a photon in the process. Stimulated emission, on the other hand, is induced by the presence of external photons that cause an already excited atom to release a second identical photon. In spontaneous emission, the emitted photon may have any frequency within the spectral line width of the transition. In stimulated emission, the emitted photon has the same frequency, phase, direction, and polarization as the stimulating photon. Spontaneous emission is non-coherent and occurs independently of external radiation. In contrast, stimulated emission is a coherent process that contributes to the amplification of light in lasers. The rate of spontaneous emission is independent of the intensity of external radiation, while the rate of stimulated emission is directly proportional to the intensity of the stimulating radiation. Spontaneous emission plays a role in processes like fluorescence and phosphorescence, whereas stimulated emission is the principle behind the operation of lasers.
This could have many names such as 'decay', 'radioactive decay', or 'radiation.
stimulated emission causes due to the energy difference between the higher and lower energy level state, but it doesn't depends in the case of spontaneous emission . spontaneous emission causes without any stimulation .In stimulated emission energy transfer is twice the energy transfer of spontaneous emission.
Spontaneous radiation is incoherent because it occurs randomly with no fixed phase relationship between emitted photons. This randomness results in a broad range of frequencies and directions for the emitted radiation, making it incoherent.
Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus; The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc
The emission of electromagnetic radiation by an excited atom is called spontaneous emission. This process occurs when an atom transitions from a higher energy state to a lower energy state, releasing a photon in the form of electromagnetic radiation in the process.
Spontaneous emission is the process where an unstable atom or molecule releases energy in the form of particles (such as photons) or waves without any external stimulation. This emission occurs when an excited atom or molecule transitions to a lower energy state, releasing the excess energy in the process.
Stimulated emission occurs when an already excited atom is triggered by an external photon to release a second identical photon. Spontaneous emission, on the other hand, happens when an excited atom releases a photon without any external stimulation.
Nuclear decay.Different types of nuclear decay include:Alpha Decay, where the nucleus ejects a charged particle made of protons and neutrons.Beta Decay, where a neutron turns into a proton, a Beta particle (an electron or positron) and a neutrino.Gamma radiation can also be emitted in these processes.
That's why it's called spontaneous emission you cannot control it. But there is a kind of emission which is called stimulated emission emission. People use stimulated emission in lasers and it can be controlled.
a particle traveling in wave form.