Quantum Beat Photoelectron Imaging Spectroscopy of Xe in the VUV

Quantum Beat Photoelectron Imaging Spectroscopy of Xe in the VUV

New on arXiv

Time-resolved pump-probe measurements of Xe, pumped at 133~nm and probed at 266~nm, are presented. The pump pulse prepared a long-lived hyperfine wavepacket, in the Xe 5p5(2P1/2)6s 2[1/2]1 manifold (E=77185 cm1=9.57 eV). The wavepacket was monitored via single-photon ionization, and photoelectron images measured. The images provide angle- and time-resolved data which, when obtained over a large time-window (900~ps), constitute a precision quantum beat spectroscopy measurement of the hyperfine state splittings. Additionally, analysis of the full photoelectron image stack provides a quantum beat imaging modality, in which the Fourier components of the photoelectron images correlated with specific beat components can be obtained. This may also permit the extraction of isotope-resolved photoelectron images in the frequency domain, in cases where nuclear spins (hence beat components) can be uniquely assigned to specific isotopes (as herein), and also provides phase information. The information content of both raw, and inverted, image stacks is investigated, suggesting the utility of the Fourier analysis methodology in cases where images cannot be inverted.

Also available on Authorea.

Full data, code & analysis notes on OSF.

Direct Ion Detection Summary (March 2018)

Direct Ion Detection Summary (March 2018)

Our Direct Ion Detection Technology Project is wrapping up in its current form, with a plan to reemerge – bigger and better – next year. See this PDF for a summary of the project to date, and plans for future work. Further details can also be found on the project webpages.

Real-time spectral characterization of a photon pair source using a chirped supercontinuum seed

Real-time spectral characterization of a photon pair source using a chirped supercontinuum seed

New article in Optics Letters.

Jennifer Erskine, Duncan England, Connor Kupchak, and Benjamin Sussman

Optics Letters Vol. 43, Issue 4, pp. 907-910 (2018)

https://doi.org/10.1364/OL.43.000907

Photon pair sources have wide ranging applications in a variety of quantum photonic experiments and protocols. Many of these protocols require well controlled spectral correlations between the two output photons. However, due to low cross-sections, measuring the joint spectral properties of photon pair sources has historically been a challenging and time-consuming task. Here, we present an approach for the real-time measurement of the joint spectral properties of a fiber-based four wave mixing source. We seed the four wave mixing process using a broadband chirped pulse, studying the stimulated process to extract information regarding the spontaneous process. In addition, we compare stimulated emission measurements with the spontaneous process to confirm the technique’s validity. Joint spectral measurements have taken many hours historically and several minutes with recent techniques. Here, measurements have been demonstrated in 5–30 s depending on resolution, offering substantial improvement. Additional benefits of this approach include flexible resolution, large measurement bandwidth, and reduced experimental overhead.

 

Bootstrapping (Ultrafast) Photoionization Dynamics – PQE 2018 (extended) video

Bootstrapping (Ultrafast) Photoionization Dynamics – PQE 2018 (extended) video

Bootstrapping (Ultrafast) Photoionization Dynamics – PQE 2018 (extended) from femtolab.ca on Vimeo.

Talk originally given as a 20min presentation at PQE 2018 (Snowbird, Utah, http://pqeconference.com/pqe2018/program). The original talk was not recorded; this is an extended version using the same slides, but with rather more introductory discussion. The abstract is given below, along with links to additional material.

More details of the work discussed in the main part of the talk can be found in:
Molecular Frame Reconstruction Using Time-Domain Photoionization Interferometry.
Marceau et. al., Physical Review Letters, 119(8), 83401 (2017).
http://doi.org/10.1103/PhysRevLett.119.083401

PQE 2018 Abstract

Bootstrapping (Ultrafast) Photoionization Dynamics
Slot: Tuesday Morning Invited Session 1
Session: Ultrafast photoionization dynamics

Photoionization is an interferometric process, in which multiple paths can contribute to the final continuum photoelectron state. At the simplest level, interferences between different final angular momentum states are clearly manifest in the energy and angle resolved photoelectron spectra; metrology schemes making use of these interferograms are thus phase-sensitive, and provide a powerful route to detailed understanding of photoionization.

The high information content of angle-resolved interferograms, combined with geometric control over the photoionization dynamics, can provide sufficient data for reconstruction of the continuum state, in terms of the constituent partial waves and phases. This has recently been explored for a range of cases, including the use of ultrafast pump-probe schemes with a bootstrapping analysis methodology: aspects of this work will be presented.

DOI: 10.6084/m9.figshare.5645509

Refs
Molecular Frame Reconstruction Using Time-Domain Photoionization Interferometry
Marceau, C., Makhija, V., Platzer, D., Naumov, A. Y., Corkum, P. B., Stolow, A., Villeneuve, D. M., Hockett, P. (2017). Physical Review Letters, 119(8), 83401. http://doi.org/10.1103/PhysRevLett.119.083401

Coherent control of photoelectron wavepacket angular interferograms.
Hockett, P., Wollenhaupt, M., & Baumert, T. (2015). Journal of Physics B: Atomic, Molecular and Optical Physics, 48(21), 214004. http://doi.org/10.1088/0953-4075/48/21/214004

Complete Photoionization Experiments via Ultrafast Coherent Control with Polarization Multiplexing.
Hockett, P., Wollenhaupt, M., Lux, C., & Baumert, T. (2014). Physical Review Letters, 112(22), 223001. http://doi.org/10.1103/PhysRevLett.112.223001

Coherent imaging of an attosecond electron wave packet.
Villeneuve, D. M., Hockett, P., Vrakking, M. J. J., & Niikura, H. (2017). Science, 356(6343), 1150–1153. http://doi.org/10.1126/science.aam8393

Time-bin-to-polarization conversion of ultrafast photonic qubits

Time-bin-to-polarization conversion of ultrafast photonic qubits

Connor Kupchak, Philip J. Bustard, Khabat Heshami, Jennifer Erskine, Michael Spanner, Duncan G. England, and Benjamin J. Sussman
Phys. Rev. A 96, 053812 – Published 6 November 2017

The encoding of quantum information in photonic time-bin qubits is apt for long-distance quantum communication schemes. In practice, due to technical constraints such as detector response time, or the speed with which copolarized time-bins can be switched, other encodings, e.g., polarization, are often preferred for operations like state detection. Here, we present the conversion of qubits between polarization and time-bin encodings by using a method that is based on an ultrafast optical Kerr shutter and attain efficiencies of 97% and an average fidelity of 0.827±0.003 with shutter speeds near 1 ps. Our demonstration delineates an essential requirement for the development of hybrid and high-rate optical quantum networks.

Quantum Metrology with Photoelectrons (book)

Quantum Metrology with Photoelectrons (book)

Book for IOP Concise Physics series, due early 2018

Dr. Paul Hockett

National Research Council of Canada

Online resources

OSF project (ID: q2v3g) with interactive content and additional resources, DOI: 10.17605/OSF.IO/Q2V3G

femtolab.ca website, posts tagged “metrology-book”

femtolab.ca website, posts tagged “video”

Abstract

Photoionization is an interferometric process, in which multiple paths can contribute to the final continuum photoelectron wavefunction. At the simplest level, interferences between different final angular momentum states are manifest in the energy and angle resolved photoelectron spectra: metrology schemes making use of these interferograms are thus phase-sensitive, and provide a powerful route to detailed understanding of photoionization. In these cases, the continuum wavefunction (and underlying scattering dynamics) can be characterised. At a more complex level, such measurements can also provide a powerful probe for other processes of interest, leading to a more general class of quantum metrology built on phase-sensitive photoelectron imaging.  Since the turn of the century, the increasing availability of photoelectron imaging experiments, along with the increasing sophistication of experimental techniques, and the availability of computational resources for analysis and numerics, has allowed for significant developments in such photoelectron metrology.

Volume I covers the core physics of photoionization, including a range of computational examples. The material is presented as both reference and tutorial, and should appeal to readers of all levels.  Volume II explores applications, and the development of quantum metrology schemes based on photoelectron measurements. The material is more technical, and will appeal more to the specialist reader.