Terahertz pulse shaping using diffractive surfaces | JoVE Visualize

Terahertz pulse shaping using diffractive surfaces

Muhammed Veli^1,2,3, Deniz Mengu^1,2,3, Nezih T Yardimci^1,2,3

¹Department of Electrical and Computer Engineering, University of California Los Angeles (UCLA), Los Angeles, CA, 90095, USA.

Nature Communications|January 5, 2021

View abstract on PubMed

Summary

Deep learning enables diffractive networks for optical pulse shaping. This compact system engineers terahertz pulses passively, controlling amplitude and phase for diverse applications like communications and spectroscopy.

Area of Science:

Optics and Photonics
Machine Learning
Wave Optics

Background:

Deep learning offers novel solutions for inverse problems in optics.
Diffractive networks integrate wave optics and machine learning for optical tasks.
Existing methods for pulse engineering can be complex and require external pumps.

Purpose of the Study:

To present a compact, passive pulse engineering system using a diffractive network.
To demonstrate all-optical shaping of arbitrary broadband pulses into desired waveforms.
To explore the application of diffractive networks for terahertz pulse manipulation.

Main Methods:

Designing diffractive layers to collectively engineer the temporal waveform of terahertz pulses.
Utilizing a diffractive network for direct pulse shaping in the terahertz spectrum.
Implementing a physical transfer learning approach for pulse-width tunability.

Main Results:

Successfully synthesized various terahertz pulses by designing diffractive layers.
Achieved independent control over amplitude and phase of terahertz wavelengths using a passive diffractive device.
Demonstrated modularity and pulse-width tunability through a transfer learning approach.

Conclusions:

The developed learning-based diffractive pulse engineering framework is compact and passive.
This method enables precise control over optical waveforms without external pumps.
The framework holds significant potential for applications in communications, ultra-fast imaging, and spectroscopy.