optical power vs distance

Kshitij Singh answered . 2025-03-21 18:32:55

To plot the average power versus distance, you need to have a relationship between the average power PavgP_{\text{avg}}Pavg? and the distance $h$ (which is the distance between the light source and the receiver). In general, the power of a signal (like optical power) tends to decay with distance, and this relationship can often be modeled using an inverse-square law or some other specific decay model depending on the type of system you're dealing with.

Assumptions:

1. You mentioned the average power is Pavg=1×1011P_{\text{avg}} = 1 \times 10^{11}Pavg?=1×1011, which seems to be in some arbitrary units (likely watts or milliwatts).
2. You mentioned the distance is 3 meters, but you may want to vary the distance to visualize the decay or relation.

Let's assume you want to model the optical power decay with distance, which can follow an inverse-square law:

Pavg(h)=P0h2P_{\text{avg}}(h) = \frac{P_0}{h^2}Pavg?(h)=h2P0??

where:

• P0P_0P0? is the initial power at a reference distance.
• $h$ is the distance.

In your case, you can generate a series of distances (say from 1 meter to 10 meters), calculate the corresponding powers using the inverse-square law, and plot the result.

MATLAB Code to Plot Average Power vs Distance:

% Parameters
P0 = 1e11;  % Initial power (example, you can adjust this)
h_values = 1:0.1:10;  % Range of distances from 1m to 10m (can adjust as needed)

% Calculate average power based on inverse square law
P_avg = P0 ./ h_values.^2;  % Inverse-square law

% Plotting the result
figure;
plot(h_values, P_avg, '-o');
xlabel('Distance (m)');
ylabel('Average Power (P_{avg})');
title('Average Power vs Distance (Inverse-Square Law)');
grid on;

Explanation:

1. Parameters:

   • P0 is the initial power at $h=1$ meter (or a reference distance of your choice).
   • h_values is the array of distances over which you want to plot the power.

2. Power Calculation:

   • We calculate the average power using the inverse-square law formula: Pavg(h)=P0h2P_{\text{avg}}(h) = \frac{P_0}{h^2}Pavg?(h)=h2P0??.

3. Plotting:

   • The plot function is used to visualize the average power against the distance, with appropriate labels and a grid for clarity.

Customizing for Your Data:

• If you have a specific relationship or data instead of using the inverse-square law, you can replace the formula with the one that suits your data.
• For example, if you have a matrix of power values corresponding to different distances, you could plot those directly.

Not satisfied with the answer ?? ASK NOW