17.1 – Measuring the Wavelength of Light (Leaving Cert Physics): Flashcards

Diffraction grating

Interference fringes

Never look directly at laser beam or its reflections

Spacing between adjacent slits in diffraction grating

Laser, diffraction grating, screen

Distance from grating to screen

1-3 metres

Distance between centres of corresponding images

$\lambda = \frac{d \sin \theta}{n}$

$\tan \theta = \frac{Y}{2D}$

Order of diffraction (1, 2, 3, etc.)

Reduces percentage error in measuring $Y$

View scale directly from above

~650 nm

Wave nature of light through interference and diffraction