/usr/include/poppler/ is in libpoppler-glib-dev 0.18.4-1ubuntu3.2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/poppler/glib/
/usr/include/poppler/glib/poppler-action.h
/usr/include/poppler/glib/poppler-annot.h
/usr/include/poppler/glib/poppler-attachment.h
/usr/include/poppler/glib/poppler-date.h
/usr/include/poppler/glib/poppler-document.h
/usr/include/poppler/glib/poppler-enums.h
/usr/include/poppler/glib/poppler-features.h
/usr/include/poppler/glib/poppler-form-field.h
/usr/include/poppler/glib/poppler-layer.h
/usr/include/poppler/glib/poppler-media.h
/usr/include/poppler/glib/poppler-movie.h
/usr/include/poppler/glib/poppler-page.h
/usr/include/poppler/glib/poppler.h