To determine the wavelength of He-Ne laser light using single slit diffraction
https://blog.oureducation.in/to-find-the-width-of-a-single-slit-by-he-ne-laser/
https://physics.iitd.ac.in/uploads/manual_UUEuAhJSeu.pdf
https://www.niser.ac.in/sps/sites/default/files/basic_page/Diffraction%20of%20light%20using%20single%20and%20double%20slit.pdf
https://blog.oureducation.in/to-find-the-width-of-a-single-slit-by-he-ne-laser/