Effects of carrier envelope phase on single shot

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Effects of carrier envelope phase on single shot XUV super continuum generation 200 Mahendra

Effects of carrier envelope phase on single shot XUV super continuum generation 200 Mahendra Man Shakya, Steve Gilbertson, Chris Nakamura, Chengquan Li, Eric Moon, Zuoliang Duan, Janson Tacket, Shambhu Ghimire and Zenghu Chang

Why do we need attosecond pulses? as fs ps 10 -18 s 10 -15

Why do we need attosecond pulses? as fs ps 10 -18 s 10 -15 s 10 -12 s Time Circulation Vibration Rotation

What Was Before reported? Single attosecond pulse at cutoff • Laser pulse: 5 fs,

What Was Before reported? Single attosecond pulse at cutoff • Laser pulse: 5 fs, 0. 75 mm Single attosecond pulse (250 as) Elaser 85 e. V 135 ev Attosecond pulse train BALTU KA et al. , Nature 421, 611( 2003) t

Our Goal • To study dynamics of electron in atoms and molecules using pump-probe

Our Goal • To study dynamics of electron in atoms and molecules using pump-probe technique with the pulse as short as 25 attosecond (one atomic unit) generated from plateau region of XUV spectrum. • To Study effect of CE phase change on the dynamics of electrons in atoms. • To determine the absolute CE phase from XUV Spectrum

What is the advantage of XUV single shot over f-2 f spectrometer ? •

What is the advantage of XUV single shot over f-2 f spectrometer ? • f-2 f set up measures the relative CE phase change. • But it is possible to determine absolute phase from XUV by investigating shot to shot variation of CE phase with polarization gated input.

What is the polarization gating? ? ? e- Right Circular Pulse ee- Td Ellipticity

What is the polarization gating? ? ? e- Right Circular Pulse ee- Td Ellipticity dependent pulse Left Circular Pulse V. T. Platonenko and V. V. Strelkov J. Opt. Soc. Am. B 16, 435 (1999)

Our Method: Generation of pulses with a time-dependent ellipticity Using Quartz plate Optic axis

Our Method: Generation of pulses with a time-dependent ellipticity Using Quartz plate Optic axis Ellipticity-dependent pulse Quartz Plate l/4 Waveplate

Polarization gate width : Simplified Formula and Example Z. Chang, PRA (2004)

Polarization gate width : Simplified Formula and Example Z. Chang, PRA (2004)

Major problem: Less number of photons Our Effort: • Phase Matched Pressure. • Small

Major problem: Less number of photons Our Effort: • Phase Matched Pressure. • Small Diverging Angle of XUV • Aluminum Filter Shield (Design)

Our Design: Higher Efficiency Gas Cell Parabolic Mirror Aluminum Filter Retractable Mirror Diffraction Grating

Our Design: Higher Efficiency Gas Cell Parabolic Mirror Aluminum Filter Retractable Mirror Diffraction Grating CCD 1 MCP 2 n. A CCD 2 MCP 1

Phase matching

Phase matching

Phase matched Plot

Phase matched Plot

From phase matching pressure to phase mismatching pressure 20 Torr 30 Torr 55 Torr

From phase matching pressure to phase mismatching pressure 20 Torr 30 Torr 55 Torr 80 Torr 60 Torr 125 Torr e. V 35. 65 8 Jan 05_Sun 38. 75 41. 85 45 48 51 54. 25 57. 35

Phase matching

Phase matching

Measurement of half the diverging angle of the XUV beam Focus Gas Cell Parabolic

Measurement of half the diverging angle of the XUV beam Focus Gas Cell Parabolic Mirror Retractable Mirror Aluminum Filter Diffraction Grating 8. 1 mrads 21. 7 mrads 1. 35 cm MCP 2 n. A CCD 2 4 cm D=0. 4 cm W 0 MCP 1 W=1. 3 cm

Measurement of half the diverging angle of the XUV beam Focus Diffraction Grating 8.

Measurement of half the diverging angle of the XUV beam Focus Diffraction Grating 8. 1 mrads 21. 7 mrads 1. 35 cm 4 cm D=0. 4 cm W 0 W=1. 3 cm

What do we expect to see with polarization gated input? ? -spatial analogy Single

What do we expect to see with polarization gated input? ? -spatial analogy Single electronslit – ion Single Collision Many Multi-slit Electron-ion Collision

CE phase Zero Degree ( Double slits analogy)

CE phase Zero Degree ( Double slits analogy)

CE phase 90 Degree ( Single Slit analogy)

CE phase 90 Degree ( Single Slit analogy)

Linear and Long pulse ( 25 fs) Harmonic spectrum (Multi- Slits analogy)

Linear and Long pulse ( 25 fs) Harmonic spectrum (Multi- Slits analogy)

Discrete harmonics with linear and long pulse(25 fs) input

Discrete harmonics with linear and long pulse(25 fs) input

Linear and Short pulse (6 fs) spectrum before polarization gating was applied ( Reduced

Linear and Short pulse (6 fs) spectrum before polarization gating was applied ( Reduced Slit Number )

Discrete but broad spectral width with linear 6 fs input before gating( reduced slit

Discrete but broad spectral width with linear 6 fs input before gating( reduced slit analogy)

Super continuum with Polarization Gated input at 100 shots (Single Slit Analogy)

Super continuum with Polarization Gated input at 100 shots (Single Slit Analogy)

Super continuum with polarization gated input at 100 shot (Single slit analogy)

Super continuum with polarization gated input at 100 shot (Single slit analogy)

Measurement of The Number of photons per pulse MCP 2 Gas Cell Phosphor Screen

Measurement of The Number of photons per pulse MCP 2 Gas Cell Phosphor Screen Parabolic Mirror Aluminum Filter Retractable Mirror Diffraction Grating CCD 1 hν e- e- MCP 2 n. A CCD 2 n. A hν Phosphor Screen en. A MCP 1

Effect of CE Phase Change on XUV Spectrum

Effect of CE Phase Change on XUV Spectrum

Single shot spectrum with CE phase unlocked 2’ 28” 2’ 20” 1’ 23” 1’

Single shot spectrum with CE phase unlocked 2’ 28” 2’ 20” 1’ 23” 1’ 06” 0’ 50” 0’ 35” 0’ 17” 0’ 0”

Single Shot Super continuum with 4 Dec 05_Sun CE Phase locked

Single Shot Super continuum with 4 Dec 05_Sun CE Phase locked

Summary • Dependence of the photon flux of polarization gated high harmonics on the

Summary • Dependence of the photon flux of polarization gated high harmonics on the target gas pressure was investigated. • Highest number of photons was estimated to be ~104 , which was enough to run single shot experiment. • We observed effect of CE phase on XUV spectra, which could be applied as a “phase meter”.

Measurement of Number of photons per pulse MCP 2 Phosphor Screen hν e- e-

Measurement of Number of photons per pulse MCP 2 Phosphor Screen hν e- e- n. A

Required Beam Size to eliminate photon loss Collimating mirror f = 1. 5 m

Required Beam Size to eliminate photon loss Collimating mirror f = 1. 5 m D=? 1. 3 cm =1. 3 cm Focusing mirror f = 250 mm Required D is D=0. 4 cm 1. 3 cm

Measurement of half the diverging angle of the XUV beam Focus Diffraction Grating 8.

Measurement of half the diverging angle of the XUV beam Focus Diffraction Grating 8. 1 mrads 21. 7 mrads 1. 35 cm 4 cm D=0. 4 cm W 0 W=1. 3 cm