Gregor Knopp (Physicist) Paul Scherrer Institute CH-5232 Villigen PSI Switzerland E-mail: gregor.knopp@psi.ch Phone: ++41-56-310-4108 Fax: ++41-56-310-2199

Research Interests

-- Investigations of molecular dynamics on an ultra short (femto-second) time scale

-- Intra and inter molecular energy transfer

-- Time and frequency resolved non-linear spectroscopy

 

Academic Trace

-- 1995 Diploma in Physics , Technische Universität Darmstadt (Germany),(CARS Spectroscopy in flames)
    (Prof. W. Seelig and Prof. J. Janicka)

-- 1996 - 1999 PHD , Universität Würzburg (Germany), (Molecular Dynamics, Femtosecond Spectroscopy)
    (Prof. W. Kiefer)

-- 1999 - 2000, Postdoc, Weizmann Institute of Science (Israel), (Non-linear Femtosecond Spectroscopy)
    (Prof. Y. Prior)

-- 2001 - now, Senior Scientist, Paul Scherrer Institute (Switzerland)
 
 

Publication List

1997:
Femtosecond Time-Resolved Pump-Probe Spectroscopy of NaI in Rare-Gas Environment.
G. Knopp, M. Schmitt, A. Materny and W. Kiefer, J. Phys. Chem. 101, 4852, (1997).

Femtosecond Time-Resolved Coherent Anti-Stokes Raman Scattering for the Simultaneous Study of Ultrafast Ground and Excited State Dynamics: Iodine Vapour.
M. Schmitt, G. Knopp, A. Materny and W. Kiefer, Chem. Phys. Lett. 270, 9, (1997).

Femtosecond Time-Resolved Four-Wave Mixing Spectroscopy in Iodine Vapour.
M. Schmitt, G. Knopp, A. Materny and W. Kiefer,  Chem. Phys. Lett. 280, 339, (1997).

The pertubation of coherent wave-packet dynamics by atom / molecule collisions: the NaI + Ar system.
H. Dietz, G. Knopp, A. Materny und V. Engel, Chem. Phys. Lett., 275, 519, (1997).

Femtosecond Spectroscopy on simple Molecular Systems: Pump - Probe and CARS Techniques.
W. Kiefer, G. Knopp, A. Materny, R. Pausch, M. Schmitt and H. Schwoerer, Chinese J. Light Scatt., 9, 45, (1997).

1998:
The Application of Femtosecond Time-Resolved Coherent Anti-Stokes  Raman Scattering for the Investigation of Ground and Excited State Molecular Dynamics of Molecules in the Gas Phase.
M. Schmitt, G. Knopp, A. Materny und W. Kiefer, J. Phys. Chem. A,102, 4059, (1998).

Femtosecond Time-Resolved CARS Spectroscopy on Binary Gas Phase Mixtures a Theoretical and Experimental Study of the Benzene/Toluene System.
O. Rubner, M.Schmitt, G. Knopp, A. Materny, W. Kiefer und V. Engel, J. Phys. Chem. A, 102, 9734, (1998).

1999:
Femtosecond Pump-Probe and Four-Wave-Mixing Spectroscopies Applied to Simple Molecules.
W. Kiefer, T. Chen, V. Engel, M. Heid, G. Knopp, A. Materny, S Meyer, R. Pausch, M. Schmitt, and H. Schwoerer, Vibrational  Spectroscopy, 19, 23, (1999).

Determination of Wavepacket Dynamics by Femtosecond Time-Resolved Pump-Probe and Four-Wave Mixing Techniques.
W. Kiefer, T. Chen, V. Engel, M. Heid, G. Knopp, A. Materny, S. Meyer, R. Pausch, M. Schmitt, and H. Schwoerer, J. Mol. Struct., 480-481, 33, (1999).

Femtosecond Spectroscopy on Simple Molecular Systems: Pump-Probe and Four-Wave Mixing Techniques.
T. Chen, H. Dietz, V. Engel, M.Heid, W.Kiefer, G.Knopp, A. Materny, S. Meyer, R. Pausch, M.Schmitt, H. Schwoerer and T. Siebert, SPIE 3733, 2, (1999).

Femtosecond Time-Resolved Dynamics of Geminate and Nongeminate Recombination: Iodine Enclosed in Nanocavities of a Microporous SIO2 Modification.
G. Flachenecker, P. Behrens, G. Knopp, M. Schmitt, T. Siebert, A. Vierheilig, G. Wirnsberger and A. Materny, J. Phys. Chem. A, 103, 3854, (1999).

2000:
Two Dimensional Time Delayed Coherent Anti-Stokes Raman Spectroscopy of Ground State Vibrational Wavepacket Dynamics.
G. Knopp, I. Pinkas and Y. Prior,  J. Raman. Spectrosc., 31, 51-58, (2000).

CARS Monitoring of Ground State Vibrational Wavepackets Prepared by Time-Delayed Femtosecond Pulses.
Y. Prior, I. Pinkas and G. Knopp,  Nonlin. Optics, 24, 233-237, (2000).

2001:
Preparation and monitoring of  high ground state vibrational wavepackets by femtosecond coherent anti-Stokes Raman scattering.
I. Pinkas, G. Knopp and Y. Prior, J. Chem. Phys., 115, 236-244 ,(2001).

Vibrational  polarization beats  in femto second CARS: A signature of dissociative pump - dump - pump wavepacket dynamics .
J. Feader, I. Pinkas, G. Knopp, Y. Prior and D. J. Tannor, J.Chem. Phys., 115, 8440-8454, (2001).

Sub-Picosecond optical pulses at the SLS storage ring.
G. Ingold, A. Streun, B. Singh, R. Abela, P. Beaud, G. Knopp, L. Rivkin, V.Schlott, Th. Schmidt, H.Sigg, J.F. van der Veen, A. Wrulich, S. Khan, PAC, Chicago, (2001).

2002:
Femtosecond Photodissociation of the Ethyl Radical C2H5.
G. Knopp , P. Beaud, P. Radi, M. Tulej, and T. Gerber, Femtochemistry and Femtobiology: ultrafast dynamics in molecular science, world scientific, 116-120, (2002).

Pressure-dependent N2 Q-branch fs-CARS measurements.
G. Knopp, P. Radi, P. Radi, M. Tulej, B. Bougie, D. Cannavo and T. Gerber, J. Raman. Spectrosc., 33,
861-865, (2002).

2003:

Scaling rotationally inelastic collisions with an effective angular momentum parameter.

P. Beaud and G. Knopp.  Chem. Phys. Lett., 371: 194, (2003).

 

Collision induced rotational energy transfer probed by time-resolved CARS.

G. Knopp, P. Radi, M. Tulej, T.Gerber and P. Beaud. J. Chem. Phys., 118: 8223, (2003).

 

Rotational inelastic collisions between N₂ and rare gases: a verification of the angular momentum scaling law.

P.Beaud, T. Gerber, P. Radi, M. Tulej, and G. Knopp. Chem. Phys. Lett., 373: 251,( 2003).

 

Determination of the ortho/para deuterium concentration ratio with femtosecond CARS.

G. Knopp, K. Kirch, P. Beaud, K. Mishima, H. Spitzer, P. Radi, M. Tulej and T. Gerber. J. Raman. Spectrosc., 34,.989-993, (2003).

 

Ortho-para equilibrium in a liquid D2 neutron moderator under irradiation.

F. Atchinson, P. Beaud, T. Brys, M. Daum,P. Fierlinger, R. Henneck, T. Hofmann, K.Kirch, G. Kühne, G. Knopp, A. Pichlmaier, A. Serebov, H. Spitzer, J. Wambach, J. Wimmer, and A. Wokaun. Phys. Rev. B. , 68, 094114, ( 2003).

 

Stimulated Emission Pumping by Two-Color Resonant Four-Wave Mixing: Rotational Characterization of Vibrationally Excited HCO(X2A')

P.P. Radi, M. Tulej, G. Knopp, P. Beaud and T. Gerber.. J. Raman. Spectrosc. 34,.1037-1044, (2003).

 

 

2004:

Femtosecond Raman time-resolved molecular spectroscopy

B. Lavorel, H. Tran, E. Hertz, O. Faucher, P. Joubert, M. Motzkus, T. Buckup, T. Lang, H. Skenderovi, G. Knopp P. Beaud, H.M. Frey, C.R. Physique, 5, 215-229, (2004).

 

Collision induced rotational energy transfer. A new scaling law probed by fs Cars

G. Knopp, P. Beaud, P. Radi, M. Tulej and T. Gerber, Femtochemistry and Femtobiology: ultrafast dynamics in molecular science, world scientific, p. 69-72, (2004).

 

Ultrafast nonlinear Raman spectroscopy for the investigation of elementary molecular dynamics.

T. Chen, G. Knopp, M. Schmitt, and A. Materny, Asian Chemistry Letters, 7, 177 (2004).

 

Collision-induced line broadening and mixing probed by femtosecond CARS

G. Knopp, P. Beaud, P. Radi, M. Tulej, and T. Gerber, Asian Chemistry Letters, 7, 237 (2004).

 

2005:

Photo-Fragment Excitation Spectroscopy (PHOFEX) by DFWM and LIF: Propensities for H­­₂CO → HCO + H near the S_o Threshold

M. Tulej, G. Knopp, P. Beaud, T. Gerber and P. P. Radi, J. Raman Spectrosc., 36, 109-115 (2005).

 

 

2006:

Nanoseconds field emitted current pulses from ZrC needles and field emitter arrays

R. Ganter, R.J. Bakker, R. Betemps, M. Dehler, T. Gerber, J. Gobrecht, C. Gough, M. Johnson, E. Kirk, G. Knopp, F. Le Pimpec, K. Li, M. Paraliev, M. Pedrozzi, L. Rivkin, H. Sehr, L. Schulz and A. Wrulich, Journal of Vacuum Science and Technology B, 24(2), 974-978 (2006).

 

Neutral molecular ZnX (X=O,OH,N) compounds in a molecular beam

D. Cannavo, G. Knopp, P. Radi, P. Beaud, M. Tulej, P. Bodek, T. Gerber, and A. Wokaun, Journal of Molecular Structure, 782, 67-72 (2006).

 

Degenerate and two-color resonant four-wave mixing applied to the rotational characterization of high- lying vibrational states of formaldehyde (A¹,A₂)⁺

M. Tulej, M. Meisinger, G.Knopp, A.M. Walser, P. Beaud, T. Gerber and P.P.Radi, Journal of Raman Spectroscopy, 37, 376-383 (2006).

 

Comparitive study of degenerate four-wave mixing and cavity ringdown signal intensities of formaldehyde in a molecular beam

M. Tulej, M. Meisinger, G.Knopp, A.M. Walser, P. Beaud, T. Gerber and P.P.Radi, Journal of Raman Spectroscopy, 37, 680-688 (2006).

 

 

2007:

Time resolved investigation of the n₁ ro- vibrational Raman band of H₂CO with fs CARS

A. Walser, P. Beaud, P. Radi, M. Tulej, T. Gerber and G. Knopp, J. Raman Spectrosc., 38, 147-153  (2007).

 

Investigation of Coriolis Perturbations on the ro-vibrational n₁ Band of H₂CO with fs-CARS

G. Knopp, A. M. Walser, P. P. Radi, P. Beaud, M. Tulej, T. Gerber, Ultrafast Phenomena XV, Springer Series in Chemical Physics, 88, 567-569, (2007) .

Multiplex spectroscopy of stable and transient species in a molecular beam

M. Tulej, M. Meisinger, G. Knopp, A.M. Walser, T. Gerber, P.P. Radi
Journal of  Raman Spectrosc. 38, 1022-1031, (2007).

 

2009:

Resonant UV- fs-TCFWM spectroscopy on formaldehyde

A. M. Walser, M. Meisinger, P. P. Radi, T. Gerber and G. KnoppPhysical Chemistry Cemical Physics, 11, 8456-8466 (2009).

 

2010:

Deperturbation study of the D³P_g v '=4 state of C₂ by applying degenerate and two-color resonant four-wave mixing

P. Bornhauser, G. Knopp, T. Gerber, P. P. Radi Journal of Molecular Spectroscopy , 262 , 69-74 (2010).

 

Degenerate and two-color resonant four-wave mixing of C₂^- in a molecular beam environment

M. Tuley, G. Knopp, T. Gerber, P. P. Radi Journal of Raman Spectroscopy , 41 , 853-858 (2010).

 

Dissection of dispersed Off-Resonant Fs DFWM of O₂

G. Knopp, P. P. Radi, Y. Sych and T. Gerber Journal of Raman Spectroscopy , , (accepted).