Unruh-DeWitt detectors interacting locally with a quantum field are systems
under consideration for relativistic quantum information processing. In most
works, the detectors are assumed to be point-like and, therefore, couple with
the same strength to all modes of the field spectrum. We propose the use of a
more realistic detector model where the detector has a finite size conveniently
tailored by a spatial profile. We design a spatial profile such that the
detector, when inertial, naturally couples to a peaked distribution of
Minkowski modes. In the uniformly accelerated case, the detector couples to a
peaked distribution of Rindler modes. Such distributions are of special
interest in the analysis of entanglement in non-inetial frames. We use our
detector model to show the noise detected in the Minkowski vacuum and in single
particle states is a function of the detector's acceleration.Comment: Revised for publication, 9 pages (+1 references page), 7 figure