In the context of electromagnetic waves, the flux density refers to the amount of energy carried by the wave per unit area and per unit time. For light waves, this is often referred to as the intensity of the light. The intensity or flux density of light is typically measured in units of watts per square meter (W/m²).
The amplitude of an electromagnetic wave, including light, refers to the maximum displacement or strength of the electric and magnetic fields as the wave oscillates. In the case of light, the amplitude of the electric field determines the brightness or intensity of the light wave. However, it's important to note that the amplitude of an electromagnetic wave can vary, and different light sources can have different amplitudes depending on various factors.
The relationship between the flux density (intensity) and the amplitude of light can be described by the following equation:
Intensity = (Amplitude)² / (2 * Z₀)
Where:
- Intensity is the flux density or light intensity in W/m².
- Amplitude is the maximum amplitude of the electric field.
- Z₀ is the impedance of free space, approximately 376.73 ohms.
It's worth mentioning that the actual values of flux density and amplitude can vary significantly depending on the specific properties of the light source and the measurement conditions.