Subcycle dynamics, resolved
Our two-color ionization study is published in Physical Review A.
Read the paperPOSTDOCTORAL RESEARCHER · SJTU
Light. Matter.
Quantum motion.
I’m Danish, a theoretical physicist exploring how intense and structured light shapes the dynamics of electrons.
Shanghai Jiao Tong UniversitySchool of Physics and Astronomy · Shanghai, China
THE SHAPE OF LIGHTω + 2ω
EᵧEₓ
Adjust the field. Discover the geometry.
About this visualization
Normalized illustrative field: Eₓ = cos(2τ) + 0.22 cos(τ + φ), Eᵧ = ε sin(2τ). The curve shows one fundamental optical period; the moving marker follows the field vector. It is an educational carrier-field model, not a TDSE calculation or measured momentum distribution.
STRONG-FIELD PHYSICSATTOSECOND DYNAMICSSTRUCTURED LIGHTQUANTUM COHERENCE
LATEST
From the research desk
A new chapter in Shanghai
I joined Shanghai Jiao Tong University as a postdoctoral researcher in theoretical physics.
Academic journeyPhD successfully defended
Atomic ionization under intense laser pulses, at Friedrich Schiller University Jena.
Explore my thesis01 / RESEARCH
A closer look at
light–matter interaction.
Analytical insight meets numerical simulation. My work connects laser-field structure with the signatures left in electron momentum, spin, and coherence.
01Strong-field ionization
Attosecond electron dynamics
Reading time in momentum space
I investigate how intense laser fields release and steer electrons on subcycle timescales. Photoelectron momentum distributions connect observable interference patterns to ionization pathways, relative optical phases, and Coulomb dynamics.
Explore this direction
Two-color attoclock interferometry offers a way to separate phase and amplitude modulation. My current work explores how helicity and pulse geometry shape the signatures carried by above-threshold ionization peaks and sidebands.
Strong-field approximation · TDSE · Saddle-point methods
Related publication02Orbital angular momentum
Structured light & nondipole physics
Beyond a uniform electric field
Twisted light introduces spatial structure and angular momentum into laser–matter interactions. I study how beam geometry and effects beyond the dipole approximation appear in electron spectra and emission asymmetries.
Explore this direction
Published work examines ionization in few-cycle twisted Bessel pulses. Ongoing projects extend the comparison between theory and momentum-resolved measurements to focused vortex fields.
Twisted Bessel & LG beams · Nondipole SFA
Related publication03Ongoing research
Spin textures & quantum coherence
Reconstructing an unseen quantum state
I explore momentum-resolved spin polarization as a probe of ionic coherence and electron–ion correlations. Spin tomography links measured projections to the structure of the underlying photoelectron spin texture.
Explore this direction
Current work develops reconstruction methods for spin-resolved momentum distributions and investigates how the reconstructed observables reveal coherence and electron–ion entanglement. These projects are ongoing.
Spin tomography · Radon inversion · Density matrices
04Ongoing research
Vortex photons & strong-field QED
Structured light at higher energies
I investigate how the wave-packet structure of electrons and photons influences scattering, with a focus on inverse Compton scattering and the transfer of optical orbital angular momentum.
Explore this direction
Ongoing theoretical work considers coherent and incoherent scattering with structured incident light, alongside relativistic descriptions of laser-driven electron dynamics.
QED amplitudes · Wave packets · Scientific computing
IN FOCUS
Physics in momentum space
Research animations from my published work.
Physical Review A · 2026
Resolving subcycle phase and amplitude modulation in strong-field ionization
Two-color laser fields reveal opposite angular shifts of neighboring above-threshold ionization peaks and sidebands. Their phase dependence links photoelectron emission angles to subcycle interference, while TDSE calculations show helicity-dependent Coulomb suppression.
View publication
Physical Review A · 2025
Photoionization dynamics in intense few-cycle twisted laser pulses
A theoretical study of atomic ionization by intense twisted Bessel pulses, exploring how orbital angular momentum and beam geometry influence photoelectron spectra and angular distributions.
View publication02 / PUBLICATIONS
Ideas, in print.
7 publications
2026
Resolving subcycle phase and amplitude modulation in strong-field ionization
DOI
Abstract summary
Two-color laser fields reveal opposite angular shifts of neighboring above-threshold ionization peaks and sidebands. Their phase dependence links photoelectron emission angles to subcycle interference, while TDSE calculations show helicity-dependent Coulomb suppression.
2025
2025
Photoionization dynamics in intense few-cycle twisted laser pulses
DOI
Abstract summary
A theoretical study of atomic ionization by intense twisted Bessel pulses, exploring how orbital angular momentum and beam geometry influence photoelectron spectra and angular distributions.
2024
Nonlinear interference and electron dynamics: Probing photoelectron momentum distributions in strong-field ionization
DOI
Abstract summary
Photoelectron momentum distributions expose nonlinear interference associated with frequency components of intense laser pulses. The work connects interference patterns with the electron dynamics underlying ionization.
2023
Pulse Cycle Dependent Nondipole Effects in Above-Threshold Ionization
DOI
Abstract summary
Strong-field approximation calculations investigate how the number of laser cycles influences nondipole ionization signatures and momentum shifts in argon and krypton.
2023
2021
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03 / ABOUT
Curiosity,
across scales.
I am a postdoctoral researcher in the School of Physics and Astronomy at Shanghai Jiao Tong University. My research centers on nonperturbative light–matter interactions, from strong-field electron dynamics to structured light and quantum coherence.
I completed my PhD in Physics at Friedrich Schiller University Jena, carrying out research at the Helmholtz Institute Jena under the supervision of Prof. Stephan Fritzsche. My doctoral work developed analytical and computational approaches to atomic ionization by intense laser pulses.
Originally from Kashmir, I’m drawn to the questions that connect a clear physical picture with a precise calculation.
2026 — NOW
Postdoctoral researcher
Shanghai Jiao Tong University · China
2022 — 2025
PhD in Physics
Friedrich Schiller University & Helmholtz Institute Jena · Germany
2019 — 2021
MSc in Physics
Guru Nanak Dev University · India
2016 — 2019
BSc in Physics
Guru Nanak Dev University · India
04 / CONTACT
Let’s talk
physics.
For research discussions, collaborations, and questions about my work.
danishdar@sjtu.edu.cnSchool of Physics and Astronomy
Shanghai Jiao Tong University
Shanghai 200240, ChinaSchool of Physics and Astronomy
Shanghai Jiao Tong University
Shanghai 200240, ChinaSchool of Physics and Astronomy