OP SESSION – Laser harmonic generation: a beat wave on steroids

Raoul Trines from STFC Rutherford Appleton Laboratory in Didcot (United Kingdom) will deliver the seminar titled “Laser Harmonic Generation: A Beat Wave on Steroids” on July 11th at 12:00 PM.

The seminar will take place in room VII of the Trilingual Building at the University of Salamanca.

Summary:
 

The laser beat-wave concept was developed in the 1980s to generate waves in low-density plasma using dual-frequency lasers. In this process, sidebands are generated in the electromagnetic wave spectrum. In this talk, we show that the beat-wave concept can also be used to study laser harmonic generation for both Gaussian beams and higher-order laser modes (e.g., Laguerre-Gaussian).

We present a novel framework to study laser harmonic generation, considering it as a multi-dimensional beat-wave process [1]. This framework allows us to calculate and visualize harmonic progressions more easily. It also includes a specific way to simultaneously analyze the frequency, spin, and orbital angular momentum (OAM) content of the harmonic radiation, providing deeper insight into this process.

We will apply our framework to the interaction of laser pulses with structured targets and show that we can achieve tunable OAM spectra and frequency combs in this configuration. We will also use our methods to analyze harmonic generation in nonlinear optics involving higher-order phase and polarization topologies, thus demonstrating that our results have many applications beyond laser-solid interactions.

[1] R. Trines et al., “Laser harmonic generation with independent control of frequency and orbital angular momentum”, Nature Communications, in press (2024), https://doi.org/10.21203/rs.3.rs-3458883/v1

Top: Schematic illustrating the generation of higher order harmonics (blue: σ= 1; green: σ=−1) of an incoming CP pump pulse (red) in (a) reflection and (b) transmissive configurations, from a threefold structured target. Bottom: Expected 2D harmonic spectrum from: (c), a flat target driven by a LP pump pulse with ℓ= 1; (d) a target with a circular structure hit by a CP pump pulse of ℓ= 0; and (e), a target with a threefold structure hit by a CP pump pulse of ℓ= 0). The blue shaded area indicates the potential for a frequency comb at ℓ= 0

No comments
adminOP SESSION – Laser harmonic generation: a beat wave on steroids

Leave a Reply

Your email address will not be published. Required fields are marked *