Manipulating Objects with Lasers: Physics of Light-Matter Interactions - Prof. Wolfgang Lo, Study notes of Physics

Download Manipulating Objects with Lasers: Physics of Light-Matter Interactions - Prof. Wolfgang Lo and more Study notes Physics in PDF only on Docsity! 1 Phys171 – Fri 2/9 Today: Chapter 4+5 Mon/Tue: Chapter 5 Light can be used to manipulate small objects Focused beam of light pulls many transparent objects toward the focal point. -> Can trap ~100 nm - 5 μm objects Physics: Transfer of momentum from light to object Incoming focused Laser beam Objective Laser Focal point 2 Move trapped objects by moving the laser 1 micon diameter silica spheres trapped and moved by a laser Tension in strings • Apply equilibrium equation (Newton 2nd law) to the traffic light and find T3 – Note: Object pulling a rope with a force: the magnitude of that force, T, is the tension in the rope • Apply equilibrium equations to the knot and find T1 and T2 Use Newtons 3rd law: Traffic Light pulls on knot with same Magnitude and opposite direction of force as knot pulls on light