Fiber Laser for ERL

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Fiber Laser for ERL Zach Ulibarri Mentor: Zhi Zhao

description

Fiber Laser for ERL. Zach Ulibarri Mentor: Zhi Zhao. Introduction. Goal: Mode locked laser oscillator 50 MHz repetition rate Designed for emittance measurement. Laser Basics. Population inversion in gain medium. Laser Basics. Stimulated photon emission. Laser Basics. - PowerPoint PPT Presentation

Transcript of Fiber Laser for ERL

Page 1: Fiber Laser for ERL

Fiber Laser for ERL

Zach UlibarriMentor: Zhi Zhao

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Introduction• Goal:– Mode locked laser oscillator– 50 MHz repetition rate– Designed for emittance measurement

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Laser Basics• Population inversion in gain medium

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Laser Basics• Stimulated photon emission

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Laser Basics• Light emits and repeats process

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Mode Locked Lasers• Saturable absorber

Intensity

Transmission

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Mode Locked Lasers

• With saturable absorber in place, random noise can create pulses

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Mode Locked Lasers

• How do we add sufficient noise to the cavity?

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Mode Locked Lasers

• How do we add sufficient noise to the cavity?

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Artificial Saturable Absorber• Wave plates create phase shift induced

intensity modulation

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Experimental Setup

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Top View

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Mode Locked Lasers

19.8ns

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Mode Locked Lasers• Detector is too slow

FWHM suggestsPulse width = 1.22 ns

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Autocorrelator Measurement• Michelson interferometer creates small delay• Aligned pulses create second harmonic

generation

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Intensity Autocorrelation

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Intensity Autocorrelation

FWHM suggests pulse width = 8ps.Very large!

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Chirp• Index of refraction depends on wavelength

• Compensate with diffraction grating

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Chirp

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Intensity Autocorrelation

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Dechirped Autocorrelation

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Dechirped Autocorrelation

FWHM = 330 fs = 1.5*220

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Interferometric Autocorrelation

FWHM suggests pulse width = 220fs

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Spectrum

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Simulated Results

200fs

Agrees with estimates

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Pulse Energy• Peak power estimated from pulse energy and

characteristicsChirped Dechirped

¿203𝑚𝑊50.5∗106

¿53.3𝑚𝑊50.5∗106

¿1.06𝑛𝐽¿ 4.02𝑛𝐽

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Peak Power

𝑃𝑝𝑒𝑎𝑘=𝐸𝑝𝑢𝑙𝑠𝑒

𝜏𝑝𝑢𝑙𝑠𝑒

¿4.02∗10− 9

200∗10−15

Chirped Dechirped

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Questions?