Video abstract for the article ‘Opto-spintronics in InP using ferromagnetic tunnel spin filters‘ by Christian Caspers, Dongyoung Yoon, Murari Soundararajan and Jean-Philippe Ansermet (Christian Caspers et al 2015 New J. Phys. 17 022004). Read the full article in New Journal of Physics iopscience.iop.org/1367-2630/17/2/022004