Shaping Pulses Before They are Born

1
Shaping Pulses Before They are Born

• Avi PeerPhysics Department and BINA center for
  nano-technology, Bar Ilan University

Shai Yefet, Naaman Amer
? - ISF, Kahn Foundation
FRISNO 11
2
Outline

• Why pulse shaping
• Standard techniques
• Mode locked oscillator cavity
• Extra-cavity shaping
• Intra cavity shaping why not ?
• Gain shaping concept
• Results
• Conclusions

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Pulse Shaping In Optics

• Control a pulse shape in time / spectrum
• Coherent quantum control
• Precision spectroscopy using frequency comb PRL
  98, 113004 (2007)
• Label free Fluorescence microscopy with
  Stimulated Raman Science 322, 1857-1860 (2008).

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Standard Mode Locked Cavity (TiS)
OC
HR
gain medium
Pump source _at_ 532 nm
Mode competition
(Gain, Loss, Dispersion)
No knob on spectrum
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Kerr Lens Mode Locked Cavities
1st stability limit - Telescope
2nd stability limit
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Pulse Shaping (Extra-Cavity)
SLM

• Phase modulation Simple, lossless
• Amplitude modulation Lossy !

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Intra Cavity Pulse Shaper ?
In cavity phase frequency shiftNo phase
shaping !
Amplitude shaping loss shapingMode competition
!
Two Colors Impossible !
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Two-Colors so far ?

• Active locking of independent lasers Opt. Lett.
  27, 312 (2002)
• Passive Locking shared Kerr medium Opt. Lett.
  29, 629 (2004)
• OPO signal and idler
• Synchronously pumped OPOs
• Time lens technique - Active modulation of a CW
  laser Optics Express 18, 24019 (2010)

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Gain Shaping
Spatial shape of pump Spectral shape of gain
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Results I
100
80
60
Power (a.u.)
40
20
0
930
840
765
745
680
Wavelength (nm)
11
Results II
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Conclusions

• Multi lobed spectra in mode locked oscillators
  are important for many applications
• No easy solution so far Synchronization of
  independent sources
• Gain shaping allows for arbitrary control of the
  oscillation spectrum.