DeepEn is a spin-off from Leib­niz Insti­tute for Pho­tonic Tech­nolo­gies (IPHT) in Jena and devel­ops hair-thin microen­do­scopes that deliver fast, high-res­o­lu­tion images from inside sen­si­tive and dynamic envi­ron­ments. By using a sin­gle opti­cal fibre as an imag­ing probe, DeepEn can bring the per­for­mance of mod­ern micro­scopes into extremely tight or sen­si­tive spaces (e.g. the brain), thus redefin­ing the pos­si­bil­i­ties of bioimaging.