Slide 1

Modal and Material Dispersion Daniil Y. Gladkov

Slide 2

Outline Hardware Types of Dispersion Data Transfer Function Future Project Proposals

Slide 3

Why does dispersion matter ? Understanding the effects of dispersion in optical fibers is quintessential in optical communications in order to minimize pulse spreading. Pulse compression due to negative dispersion can be used to shorten pulse duration in chirped pulse lasers

Slide 4

Hardware and setup

Slide 5

Laser Diode Power Output Profile

Slide 6

Pulsed Fiber Laser System From Wesley Hughes and Jared Greens Presentation

Slide 7

Pulse Generator and Amplifier

Slide 8

Modal Dispersion

Slide 9

Material Dispersion

Slide 10

Anomalous Dispersion Pulses higher frequency have faster phase velocity than the lower frequency components Responsible for negative dispersion, pulse compression, and soliton formation http://www.falstad.com/dispersion/normal.ht ml http://www.falstad.com/dispersion/normal.ht ml

Slide 11

150 Picosecond Pulse Generator

Slide 12

1 Nanosecond Pulse with Amplifier

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Femtosecond Pulse Laser

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1km, 2km, 3km Fiber with Femtosecond Pulse Laser Results 1 km - pulse width: 215 ps : 572ps 2 km - pulse width: 385 ps : 2.4ps 3 km - pulse width: 382 ps: 1.62ps Results do not agree with theory

Slide 15

20.56 km Fiber with 1 Nanosecond Pulse Laser Results

Slide 16

Multimode Fiber

Slide 17

Transfer Function

Slide 18

Input Pulse Fitting

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Output Pulse Fitting

Slide 20

Computation of Transfer Function

Slide 21

Suggestions for Future Projects Use Optical amplifier to boost output signal Spectral profiling of pulses Anomalous Dispersion modeling Better fitting and transfer function modeling High powered laser to overcome attenuation More variations of fiber lengths Soliton formation