Last December, we heard the incredibly sad news of the sudden passing of our great friend Bart van Tiggelen (from LPMMC, Grenoble). Bart was a great scientist, an outstanding theoretical physicist (on light scattering, Anderson localization,  wavefront shaping, imaging, etc. etc. etc.) always a keen eye on experiments, he’d happily join us in the lab to discuss over some complicated gizmo.

One may say that Bart was a COPS-avant-la-lettre: he did his PhD research on multiple light scattering with Ad Lagendijk and Adriaan Tip at the FOM-Instituut AMOLF in the early 1990s, where they discovered the famous energy velocity (see papers here on the COPS website.)

Bart was a real “Mensch”, full of integrity and honor. Always good-humored and very kind, but if you’d dare mess with, say, the optical theorem or the t-matrix (not the same as the T-matrix…!) you would be in for a hard time, regardless of your Nobel Prize or whatchamacallit.

Bart was always on the barricades for open access, diversity, and the voice of everyone. We treasure Bart’s great kindness to everyone, young people (students, mentees), visitors, all. Others are better qualified to praise Bart’s hard work and great efforts for the whole community (CNRS, SFP, EPL) open-access publishing, (master)classes to students, on every topic: https://lnkd.in/e5mfS_6y.

COPS is very proud that earlier in 2025, we published a great, great paper (in every sense!) with Bart in Physical Review on a new theory of wavefront shaping to focus light inside opaque materials.

We treasure Bart’s wonderful and absurd sense of humor; his love of the great outdoors (see e.g.: https://lnkd.in/eh3BEYbb) – hence the shock of hearing of his recent sudden ordeal – and of course his great love for his dear wife, great children and grandchild, and family. And even when Bart is not with us anymore, he will definity live on. For instance, we will carry him in our hearts wherever COPS may go ❤️.