Measure the wavelength of LASER

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Unpack the relationship between the frequency, speed and wavelength of a wave.

What, really, is a wavelength and how is it measured?  In this STEM lab, high school students work with a laser and diffraction grating to produce a double slit interference pattern. With data they collect, and some math, they  solve for the wavelength of a real laser.

Grade Range:

60 to 90 Minutes


Laser Blox, diffraction grating, ruler or meter stick, pen and paper

NGSS Connections

PS4.B – Electromagnetic Radiation

  • Use mathematical representations to support a claim regarding the relationships between the frequency, wavelength and speed of waves traveling in various media.

Science and Engineering Practices

  • Use mathematical representations of phenomena or design solutions to describe and/or support claims and/or explanations