Uses a digital spectrometer (connected to a computer) to measure the emission spectra of various light sources (including LEDs). Uses thin film interference to measure the radius of a lens and angle of a thin air wedge.


  • Develop an understanding of thin film interference and thus perform physical measurements using the phenomena.
  • Develop a practical understanding of emission spectra.
  • Develop an understanding of how band gap and spectral lines apply to LEDs.
  • Use measurements to calculate the band gap of LEDs.


  • The Digital spectrometer can also be configured to measure absorption spectra.

Links to Stage 6 Physics Syllabus Content

PH12-15/Origins of the Elements

  • Account for the production of emission and absorption spectra and compare these with a continuous black body spectrum. (ACSPH137).