Stabilizing the carrier envelope phase of the kansas light source
This presentation is the property of its rightful owner.
Sponsored Links
1 / 37

Stabilizing the Carrier-Envelope Phase of the Kansas Light Source PowerPoint PPT Presentation


  • 94 Views
  • Uploaded on
  • Presentation posted in: General

Stabilizing the Carrier-Envelope Phase of the Kansas Light Source. Eric Moon Zuoliang Duan 11-9-2005. Outline. Theoretical Description of the CE phase Why do we care about the CE phase? Can we control it? Yes! Here’s how it’s done for the KLS and why it works.

Download Presentation

Stabilizing the Carrier-Envelope Phase of the Kansas Light Source

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Stabilizing the carrier envelope phase of the kansas light source

Stabilizing the Carrier-Envelope Phase of the Kansas Light Source

Eric Moon

Zuoliang Duan

11-9-2005


Outline

Outline

  • Theoretical Description of the CE phase

  • Why do we care about the CE phase?

  • Can we control it? Yes! Here’s how it’s done for the KLS and why it works.

  • Single-Shot CE Phase Measurement Setup

  • Results

  • Future Plans


Why do we care about controlling the change of the carrier envelope phase

Why do we care about controlling the change of the carrier-envelope phase?

  • Important for experiments utilizing few-cycle laser pulses, e.g. High Harmonic Generation

  • Can use a stabilized frequency comb to perform spectroscopy.

  • Related to this year’s Nobel prize!

  • More applications to come!


Results from others

Results from Others

  • Fortier et al1, have reported phase coherence times of 326 s.

  • Witte et al2, have observed coherence times of 500 s.

  • Our group has observed coherence times of 85 s.

  • The main goal is to achieve long term, on the order of hours, for running experiments.

[1] Fortier et al, IEEE Journal Topics Quantum Electron, Vol. 9, 1002-1010, 2003

[2] Witte et al, App. Physics B, 78, 5-12, 2004


Theory 1

Theory1

Mode-locked lasers emit a regular train of pulses.

For a single laser pulse:

Envelope-function

Carrier-frequency

Carrier-envelope phase

[1] Fortier et al, IEEE J. Select. Topics Quantum Electron., vol. 9, pp.1002-1010,2003.


Theory 11

Theory1

Time-Domain Description of the Mode-Locked Pulse Train

[1] Fortier et al, IEEE J. Select. Topics Quantum Electron., vol. 9, pp.1002-1010,2003.


Theory 12

Theory1

Due to material dispersion inside the laser cavity, the CE phase changes.

The laser cavity length:

[1] Fortier et al, IEEE J. Select. Topics Quantum Electron., vol. 9, pp.1002-1010,2003.


Theory 13

Theory1

Mode-Locked Pulse Train in the Time Domain:

Mode-Locked Pulse Train in the Frequency Domain:

[1] Fortier et al, IEEE J. Select. Topics Quantum Electron., vol. 9, pp.1002-1010,2003.


Frequency comb and laser spectrum 1

Frequency Comb and Laser Spectrum1

[1] Fortier et al, IEEE J. Select. Topics Quantum Electron., vol. 9, pp.1002-1010,2003.


Theory

Theory

The regular spacing of the frequency comb allows access to the change of the carrier-envelope phase.

How?

Can use a self-referencing technique!


Theory 14

Theory1

The self-referencing technique requires an octave-spanning spectrum of the laser.

Beating the second harmonic and fundamental frequency combs of the laser yields a frequency proportional to the change of the carrier-envelope phase.

[1] Fortier et al, IEEE J. Select. Topics Quantum Electron., vol. 9, pp.1002-1010,2003.


Theory1

Theory

  • The CE phase change can be controlled by locking the offset frequency, f0, to a known frequency.

  • In the case of the KLS, f0 is set equal to one-quarter of the repetition rate of the oscillator.


Experiment

Experiment

  • The KLS utilizes a Kerr-Lens Mode locked Ti:Sapphire Oscillator emitting a ~77 million pulses per second.

  • The pulses are roughly 12 fs at the output of the laser and carry nJ energy per pulse.

  • The oscillator is the starting point for the self-referencing technique.


Why not use the amplifier output

Why not use the amplifier output?

One reason: Spectrum too narrow!


Stabilizing the carrier envelope phase of the kansas light source

KLS Oscillator Cavity

Pump

M5

Lens

A1

Ti:S

M1

ECDC-Module

M0

M6

M7

CP

M9

M3

OC

M8

M2

M10

M4E

Ultrashort

Pulse

Output

M4


Stabilizing the carrier envelope phase of the kansas light source

Stabilization Experimental Setup

offset frequency

photodiode

APD

collimating Lens

f=30mm

focusing Lens

f=30mm

focusing Lens

f=30mm

HR1064nm

mirror

HR532nm

mirror

BBO

crystal

λ/2

half wave plate 1064nm

polarizing

beam-splitter

532nm

filter RG715

HR532nm mirror

λ/2

half wave plate

532nm

λ/2

HR532nm mirror

half wave plate

532nm

dichroic beam splitter

HR 532nm,HT1064nm

polarizing

beam-splitter

532nm

out-coupling

objective

f=8.55mm

in-coupling

objective

f=7.5mm

IR mirror

Silver

mirror

PCF

λ/2

half wave plate 800nm

Chirped

mirror

Chirped

mirror

grating

900lines/mm

From fs Laser


Stabilizing the carrier envelope phase of the kansas light source

532 nm

1064 nm


Stabilizing the carrier envelope phase of the kansas light source

~1064 nm, Doubled in BBO Crystal


Offset frequency while phase locked

Offset Frequency while Phase Locked


Observation of beat note and frequency comb

Observation of Beat Note and Frequency Comb

frep-f0

f0=19.375MHz


Ce phase stability after pulse amplification 2

CE Phase Stability After Pulse Amplification2

  • A second f-2f interferometer after the KLS amplifier provides a means for quantifying the CE phase stabilization stability.

  • 10% of the KLS amplifier output is sent to the experimental setup.

  • White-light is generated in a sapphire plate and a BBO crystal provides second-harmonic generation.

  • [2] Baltuska et al.,IEEE J. Select. Topics Quantum Electron., vol. 9, pp. 972-989, 2003.


Theory 2

Theory2

Interference between the white light and second harmonic pulses:

Phase of the Interference Signal:

The shot-to-shot change of this phase can be monitored by the second f-2f setup.

  • [2] Baltuska et al.,IEEE J. Select. Topics Quantum Electron., vol. 9, pp. 972-989, 2003.


Stabilizing the carrier envelope phase of the kansas light source

Experiment

locking

electronics

Pump

AO modulator

M5

Lens

A1

Ti:S

M1

M0

M6

M7

HR IR mirror

BS

50:50

CP

M3

OC

M8

M2

M4E

M4

nonlinear

interferometer

spectral

broadening

HR IR mirror

BS 9:1

stretcher

compressor

amplifier

1kHz fs laser

HR IR mirror

Single-shot phase measurement


Stabilizing the carrier envelope phase of the kansas light source

f-2f Interferometer after KLS Amplifier

1kHz fs laser

concave silver

Mirrors: f=100mm

half wave plate

half wave plate

spectrometer

FCWL

two silver mirrors

SHG

VNA

VNA

sapphire

d=2.3mm

FCWL: fundamental

Continuum white light

silver mirrors

silver mirror

polarizer

BBO

f=70mm

∆T=0.265ps

SHG

FCWL

532nm HR mirror

532nm HR mirror

f=75mm


Stabilizing the carrier envelope phase of the kansas light source

Spectrum of the Second Harmonic generated in the BBO Crystal


Single shot not locked

Single-Shot: Not Locked


Line out of the interference pattern

Line-Out of the Interference Pattern


Stabilizing the carrier envelope phase of the kansas light source

1 pulse

Phase-Locked

Not Phase-Locked


Stabilizing the carrier envelope phase of the kansas light source

51 pulses

Phase-Locked

Not Phase-Locked


Stabilizing the carrier envelope phase of the kansas light source

101 pulses

Phase-Locked

Not Phase-Locked


Stabilizing the carrier envelope phase of the kansas light source

200 pulses

Phase-Locked

Not Phase-Locked


Stabilizing the carrier envelope phase of the kansas light source

1000 pulses

Phase-Locked

10000 pulses

phase-locked

103000 pulses

Phase-locked


Summary

Summary

  • The change of the carrier-envelope phase of the KLS has been stabilized.

  • A technique for observing the carrier-envelope phase change shot-to-shot has been utilized.

  • CE phase coherence times of up to 85 seconds have been observed.


Future

Future

  • Send a slow CE phase drift signal from the second f-2f interferometer back to the locking electronics to achieve longer locking times.


Thanks

Thanks!

  • Dr. Zenghu Chang

  • Al Rankin

  • KLS Members: Mahendra Shakya, Shambhu Ghimire, Chris Nakamura, Chengquan Li, and Steve Gilbertson

  • Zuoliang Duan for being a great partner on this project.

  • Dr. Corwin and Dr. Washburn


  • Login