Problem 49652. Find the spot diameter from the intensity distribution matrix of single spot (circle)

Created by Sibi

Solve Later

Intensity distribution will be same as gaussian dsitribution and check for gaussian beam distribution
Distance between each index will be equal to 1 mm. Grid will be n*n matrix of distribution . n will be odd number . If n=3 center of the spot will be (2,2)
Find spot diameter in mm.
Hint : w(z) is the radius of the laser beam where the irradiance is 1/e2 (13.5%) of Intensity
example 
x    0.0000    0.0045    0.0335    0.0045    0.0000
    0.0045    1.8316   13.5335    1.8316    0.0045
    0.0335   13.5335  100.0000   13.5335    0.0335
    0.0045    1.8316   13.5335    1.8316    0.0045
    0.0000    0.0045    0.0335    0.0045    0.0000]
I=100 (max intensity);
I(13.5 %)=13.5
radius=1 mm;Spot diameter=2 mm

Solve

Solution Stats

26 Solutions
4 Solvers

Last Solution submitted on Sep 01, 2023

Last 200 Solutions

Problem Comments

3 Comments

3 Comments

Tim on 30 Dec 2020

In your example, the distance from 100 to 13.53 is sqrt(2), so the diameter should be 2*sqrt(2). The test suite values also do not seem to make sense.

Sibi on 5 Jan 2021

The example had an error, now it's fixed.

Dyuman Joshi on 13 Aug 2021

Test 7, max(x(:))=152; 13.5% of 152 = 20.52, which is not present in the matrix. Same goes for the rest of the cases.
I feel like I am missing something.

@Sibi

Solution Comments

Show comments

Problem Recent Solvers4

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 49652. Find the spot diameter from the intensity distribution matrix of single spot (circle)

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers4

Suggested Problems

More from this Author33

Problem Tags

Community Treasure Hunt

Problem 49652. Find the spot diameter from the intensity distribution matrix of single spot (circle)

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers4

Suggested Problems

More from this Author33

Problem Tags

Community Treasure Hunt

Players