EEE036 Understanding Laser Presented by Li Ruiqian & Wu - PowerPoint PPT Presentation

EEE036 Understanding Laser Presented by Li Ruiqian & Wu Hongrui

Looks familiar?

Part I: What is laser?

LASER L ight A mplification by S timulated E mission of R adiation

How does it work?

Some variations

Laser Mechanism

Part II: Special Properties of laser

Monochromaticity Something with a single colour

Coherence in laser ● Spatial coherence Same time, different point ● Temporal coherence Different time, same point

Simple Illustration

Directionality & Brightness Remember him? You shall not pass unless in the right direction!!!

Part III: Implications of laser

Ring lasers Commonly seen in cars and ships ● A device used to measure rotation ●

Mechanism of ring lasers

Optical Communication ● The use of semiconductor lasers ● Present in transmitters ● Higher output power and efficiency ● Can be easily modulated

Part IV: Experiments

Simulation & Analysis

Erbium-Doped Fiber Amplifier (EDFA)

Data input Experiment 1 2 3 Pump Wavelength 980 980 980 (nm) Signal 1550 1550 1550 Wavelength (nm) Pump Power 100 150 100 (mW) Signal Power 0.03 0.03 0.06 (mW) Doped Fiber 10 10 10 Langth (m) Doped Fiber Core 5.5 5.5 5.5 Diameter (um)

Graphs

Analysis > Effects of varying Signal Power input > Effects of varying Pump Power input > Implications: Different power source on the power output of the laser

Conclusion

Thank you for listening