Question

How is transmitting intensity calculated?

Answer 1

1. An electromagnetic wave's $I$ intensity is inversely proportional to the electric field vector's vector magnitude, squared.
2. The transmitted light will have an intensity equal to $I_{transmitted}=I_0{\cos }^2\theta$ when polarized light of intensity $I_0$ is passed through the polarizer.
3. The angle formed in this case between the filter's axis and the incident light's polarizing direction is denoted by the symbol $\theta$. Along the polarizer's axis, the transmitted light will become polarized.

This is called the law of Malus. If $\theta ={90}^o$ the transmitted intensity is zero.

1. The amount of electromagnetic wave (light) passing through a surface or optical component is measured by the transmission coefficient.
2. You can compute transmission coefficients based on the wave's amplitude or intensity.
3. The ratio of the value following the surface or element to the value prior is used to calculate either. In most cases, the transmission coefficient for intensity and total power is the same.

By multiplying the energy density at a given point in space by the energy's speed, one can calculate intensity. The unit of power will be divided by the area to determine the intensity value.