Surface Plasma Attosources Group

Surface Plasma Attosource (SPA) Group members:

	Dr. Subhendu Kahaly (Group Leader, senior research fellow)
	Dr. Sudipta Mondal (research fellow)
	Naveed Ahmed (early-stage researcher)
	Mojtaba Shirozhan (early-stage researcher)

Attosource beamlines concerned:

SHHG-SYLOS & SHHG-HF

SHHG-SYLOS will be driven by state of the art 45/100 mJ, 1 kHz, CEP stabilized SYLOS laser whereas SHHG-HF will be driven by state of the art PW laser (details of the laser and cross reference should be arranged). Detailed design, parameters and challenges regarding these two beamlines are available in the articles (J. Phys. B At. Mol. Opt. Phys. 50, 132002 (2017), “The Extreme Light Infrastructure – Attosecond Light Pulse Source (ELI-ALPS) project.," in Progress in Ultrafast Intense Laser Science XIII (Springer International Publishing) and Surface-Plasma Attosource Beamlines at ELI-ALPS, JOSA-B).

The final attosecond pulse parameters which are aimed to be achieved are given in the table below.

Work Objectives of SPA

The primary objectives of SPA group are the following:

Overseeing and managing the design and development of two sophisticated, state of the art beamlines based on high-order harmonics generation by the relativistic interaction of high intensity ultrashort pulse lasers with surface plasma (SHHG-SYLOS and SHHG-HF) and coordinating with the international developers and R&D contractors to see through successful design to implementation process.
Undertaking R&D and collaborative activities to optimize these SHHG beamlines for achieving the best possible interaction conditions and the secondary radiation parameter space for diverse fundamental and application based experiments.
Maintaining steady operation of this complex and unique instruments and adapting them for providing the best service for user defined experiments.
Developing and engaging in research methodologies (both numerical and experimental) that focus on generation of secondary radiation from the interaction of intense laser with plasma based targets.
Undertaking R&D and collaborative activities on metrology and beam transport of XUV from SHHG.

R&D activity

SPA group is strongly motivated in general on studies of how an intense ultrashort light pulse interacts with dense material and what leads to the subsequent generation of secondary radiations from this interaction. The major interest of the SPA group lies in understanding the different physics that manifests in the laser-matter interaction as the light field strength changes abruptly by several orders of magnitude, from nonionizing values to values where electron motion becomes relativistic, over only few femtoseconds. The different topics that we are currently engaged in are related to:

1-1 Relativistic effects of ultrashort pulse propagation in transparent inhomogeneous plasma medium and probing questions like what is happening to the plasma and the light pulse in the process. These works have important consequences in tailoring and enhancing the light field prior to the intended interaction for laser wake field acceleration as well as SHHG.

1-2 Generation of super strong attosecond light fields by engineering target and interaction conditions in the few cycle regime of relativistic interaction with surface plasmas. In this work we are trying to investigate how few cycle lasers can give unique interaction conditions for attosecond pulse generation at relativistic intensities.

1-3 We are also working actively on disseminating the SHHG beamline opportunities by defining and exploring novel ways to pursue science with the SHHG beamline interaction parameters. This project provides unique opportunity to synergize attosecond science with laser plasma experiments and has important consequences in defining the user possibilities with these beamlines.

1-4 Generation of attosecond pulses which lies at the heart of ELI-ALPS demands a thorough understanding of the process itself, if possible from a common perspective. On the other hand, the theoretical tools to pursue High Harmonic Generation from atoms to plasma encompasses a remarkably wide parameter space in terms of driving laser characteristics and driven material features which calls for diverse and distinct physical concepts and methodologies to understand these processes. In this project we are focusing on identifying and synthesizing valid approaches with commonalities and similarities within these apparently different interaction domains. This is a very important undertaking and can provide a common introduction to a wide ranging topics in the field that are seemingly disconnected.

Publications (Recent 2016 onwards):

Journal of the Optical Society of America B. 35, A-93 (2018)

Link: https://www.osapublishing.org/josab/abstract.cfm?uri=josab-35-5-A93

Phys. Rev. Lett. 121, 023201 (2018)

Link: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.023201

Phys. Rev. Lett. 119, 155001 (2017)

Link: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.155001

Optics Express 25, 17511 (2017)

Link: https://www.osapublishing.org/oe/abstract.cfm?uri=oe-25-15-17511#articleBody

J. Phys. B At. Mol. Opt. Phys. 50, 132002 (2017)

Link: http://iopscience.iop.org/article/10.1088/1361-6455/aa6ee8/meta

Nature Communications 8, 16061 (2017)