modern physics

How Lasers Work

Explore stimulated emission in 3D — watch photons trigger cascading emissions, population inversion in a gain medium, and an optical cavity producing a coherent laser beam.

Lasers

A-Level

LASER = Light Amplification by Stimulated Emission of Radiation. A population inversion is created in a gain medium where more atoms are in an excited state than ground state. A passing photon stimulates emission of identical photons, creating a coherent beam.

Pump Power5.0arb.

Cavity Length20cm

📐 Formulas

E = hf = \frac{hc}{\lambda}Energy of laser photons

N_2 > N_1Condition for lasing

📋 Syllabus

AQA3.13.6

OCR6.5.2