We calculate the photon emission of a high finesse cavity moving in vacuum.
The cavity is treated as an open system. The field initially in the vacuum
state accumulates a dephasing depending on the mirrors motion when bouncing
back and forth inside the cavity. The dephasing is not linearized in our
calculation, so that qualitatively new effects like pulse shaping in the time
domain and frequency up-conversion in the spectrum are found. Furthermore we
predict the existence of a threshold above which the system should show
self-sustained oscillations.Comment: 10 pages, 3 figures, LaTeX, to appear in European Physical Journal
D3, replaced version with few minor grammatical change
