# Reflection coefficient calculation

• kaje
In summary, the conversation discusses the calculation of the reflection coefficient of walls for incident light of different wavelengths. The input data needed for this calculation is the properties of the wall material. The conversation also mentions the use of Lambertian formula of DC channel gain and the possibility of the reflection coefficient changing over time due to the characteristics of the paint. Another question is raised about the bandwidth of LED used in visible communication and whether it extends to the infrared region.

#### kaje

Hi there,

I am wondering how to calculate the reflection coefficient of walls upon incident light versus wavelengths,,

thanks

Thanks for your reply, i mean part of the light reflected and a part get absorbed as infrared light is used as a source..

To calculate knowing what? You need to know something about the wall (and the light) in order to calculate the coefficient of reflection. What is your input data?

Hi,thanks for reply, OK, am simulating a system inside a room of (3x3x2.5)m^3 , the only source is a bulb light fixed on the ceiling,so I would like to calculate the reflection coefficient of the walls which then used in Lambertian formula of DC channel gain...

The size of the room is not enough information to "calculate" the coefficient of reflection for the walls.
Again, what do you know about the properties of the walls? The reflection depends on the materials on the two sides of the interface. In this case, is probably air and the paint on the wall. But the paint may not even be a homogeneous material. You may be more successful if you look up the reflection for that specific paint. But it will be just a rough estimate, the characteristics of the paint will change in time.

thank u so much , actually just a normal room ,but I don't know what material is it? I mean ,it could be any kind of office wall.Do you mean,if I can get the
reflection of the material ,that would be the reflection coefficient...

Thanks,I have got another question please, for LED that is used in visible communication, Does the bandwidth sharply be between (400-700)nm or could extend to IR-region like incandescent lamps...

Many thanks

## What is a reflection coefficient?

A reflection coefficient is a measure of the amount of light or other electromagnetic radiation that is reflected from a surface. It is typically expressed as a ratio between the reflected and incident intensities or amplitudes of the radiation.

## Why is calculating the reflection coefficient important?

Calculating the reflection coefficient is important in many fields of science and engineering, such as optics, acoustics, and electromagnetics. It allows us to predict and understand how much of the incident radiation will be reflected from a surface, which is essential in designing and optimizing various devices and systems.

## How is the reflection coefficient calculated?

The reflection coefficient is calculated by taking the ratio of the reflected intensity or amplitude to the incident intensity or amplitude. In some cases, this can be done using simple equations, while in others it may require more complex calculations or simulations.

## What factors can affect the reflection coefficient?

The reflection coefficient can be affected by a variety of factors, including the angle of incidence, the properties of the materials involved, and the wavelength or frequency of the incident radiation. The surface roughness and texture can also play a role in the reflection coefficient.

## How can the reflection coefficient be measured experimentally?

The reflection coefficient can be measured experimentally using various techniques, such as reflectometry, ellipsometry, or interferometry. These methods involve directing a beam of radiation at the surface and measuring the reflected radiation, which can then be used to calculate the reflection coefficient.