Measuring Micrometer-scale Lengths Using Diffraction
Introduction (100 words)
Measuring and estimating lengths is one of the fundamental aspects of understanding physical matter that constitutes the universe. Different measurement techniques are developed depending on the length scale, accuracy, and precision needed for the measurement of our interest. In this experiment, we use a simple toy laser to determine the distance between two pits on a CD and a DVD. (A pit is a micrometer-scale feature present in old CDs and DVDs; Multiple such pits enable the storage of data onto them.)
Precautions
- Never point a laser light towards the eyes.
- Be cautious of reflecting surfaces that might accidentally direct light in your/others' eyes.
Materials required
- Laser light Source (Toy laser or Laser pointer)
- Old Compact disk (CD) or DVD
- Measuring Ruler (30 cm)
- Pencil