An interference bench. Build slits, gratings and interferometers, align them with a laser, put the screen where you like, and measure the fringes. Then swap the laser for single photons. No clock: take your time.
Source
Bench, top view
Click a part to jump to its controls. Drag the screen along its rail. Not to scale except where distances are written.
Adjustments
Controls
Type a value, drag a slider, or use the step buttons. Arrow keys work on a focused slider.