Young's Double-Slit Experiment

Laser

Top-down View

Wavelength ($\lambda$) 650 nm

Slit Separation ($a$) 0.40 mm

Screen Distance ($D$) 1.40 m

Fringe Separation ($\Delta y$) 2.28 mm

-20mm -10mm 0 +10mm +20mm

Interference Pattern

$$ \Delta y = \frac{\lambda D}{a} $$

$$ I = I_0 \cos^2\left(\frac{\pi a y}{\lambda D}\right) $$

Try answering question (a)(i) from your sheet: How can you increase the average separation ($\Delta y$)?