Control of the temporal and polarization response of a multimode fiber

Control of the spatial and temporal properties of light propagating in disordered media have been demonstrated over the last decade using spatial light modulators. Most of the previous studies demonstrated spatial focusing to the speckle grain size, and manipulation of the temporal properties of the achieved focus. In this work, we demonstrate temporal control of the total impulse response integrated over all the spatial and polarization modes propagating through a multimode fiber. We notably demonstrate a global enhancement of light intensity at a chosen arrival time, as well as attenuating light intensity at an arbitrary delay. We also demonstrate the full polarization control of such engineered states and a multiple control at different delay times, which opens interesting perspectives for non-linear imaging through complex systems and high power fiber lasers.Comment: 10 pages including main and supplemental documents. 5 figures in the main manuscript, 4 figures in the supplementa

Temporal recompression through a scattering medium via a broadband transmission matrix

The transmission matrix is a unique tool to control light through a scattering medium. A monochromatic transmission matrix does not allow temporal control of broadband light. Conversely, measuring multiple transmission matrices with spectral resolution allows fine temporal control when a pulse is temporally broadened upon multiple scattering, but requires very long measurement time. Here, we show that a single linear operator, measured for a broadband pulse with a co-propagating reference, naturally allows for spatial focusing, and interestingly generates a two-fold temporal recompression at the focus, compared with the natural temporal broadening. This is particularly relevant for non-linear imaging techniques in biological tissues.Comment: 4 pages, 3 figure

Spatiotemporal coherent control of light through a multiply scattering medium with the Multi-Spectral Transmission Matrix

We report broadband characterization of the propagation of light through a multiply scattering medium by means of its Multi-Spectral Transmission Matrix. Using a single spatial light modulator, our approach enables the full control of both spatial and spectral properties of an ultrashort pulse transmitted through the medium. We demonstrate spatiotemporal focusing of the pulse at any arbitrary position and time with any desired spectral shape. Our approach opens new perspectives for fundamental studies of light-matter interaction in disordered media, and has potential applications in sensing, coherent control and imaging.Comment: revised version, 5 pages, 4 figures, and supplementary materials(including 5 figure

Roadmap on spatiotemporal light fields

Spatiotemporal sculpturing of light pulse with ultimately sophisticated structures represents the holy grail of the human everlasting pursue of ultrafast information transmission and processing as well as ultra-intense energy concentration and extraction. It also holds the key to unlock new extraordinary fundamental physical effects. Traditionally, spatiotemporal light pulses are always treated as spatiotemporally separable wave packet as solution of the Maxwell's equations. In the past decade, however, more generalized forms of spatiotemporally nonseparable solution started to emerge with growing importance for their striking physical effects. This roadmap intends to highlight the recent advances in the creation and control of increasingly complex spatiotemporally sculptured pulses, from spatiotemporally separable to complex nonseparable states, with diverse geometric and topological structures, presenting a bird's eye viewpoint on the zoology of spatiotemporal light fields and the outlook of future trends and open challenges.Comment: This is the version of the article before peer review or editing, as submitted by an author to Journal of Optics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

Controlling the temporal impulse response of light propagating through a multimode fiber

We demonstrate how to control the polarization-resolved temporal impulse response of transmitted light through a multimode fiber. We show enhancing or attenuating the total temporal impulse response at arbitrary delays and polarization states

Temporal control of the combination over all spatial and polarization modes propagating through a multimode fibre

Over the last decade, wavefront shaping techniques with spatial light modulators have enabled the control of coherent light through disordered systems, like biological tissues or multimode fibre that has suffered from scattering or mode mixing. Beyond spatial focusing of light on a single speckle grain, these techniques have been extended to the control of broadband light. Spatio-temporal focusing has been achieved, which corresponds to compensation for the pulse broadening in a single speckle grain [1]. The temporal control of light in all the spatial positions, including the full polarization control, has however not been achieved

Cold-fusion: A superconducting scheme

Submitted to Europhysics LettersSIGLEITItal