Measuring wavelength of laser beam using single slit diffraction: a simple but precise experiment using webcam and ImageJ software

Abstract

Abstract We explore a precise method for determining the wavelength of light using a single-slit diffraction experiment. Normally, within a college level physics lab, an optical bench and a light detector arrangement is used in this experiment and the position of the maxima and minima are manually determined. This method is inaccurate, lengthy, and time consuming. We replace the light-detector by a paper-screen and webcam arrangement to record the image of the diffraction pattern with a computer. Then the recorded images are analysed with a software called ImageJ to determine the span of central maxima which is finally used to determine the wavelength of the incident light.