Photoionization spectrum of 85RbCs molecules produced by short range photoassociation

Abstract

We present photoionization (PI) spectrum of ultracold ground state 85RbCs molecules formed by spontaneous decay from J=1, v=8 rovibrational level of (2)Π0−3 short range excited state molecules, which are produced from a space-adjustable dark spontaneous force optical trap. PI spectrum is obtained by scanning PI laser when photoassociation laser is locked by utilizing transfer cavity technique based on an ultrastable He–Ne laser as a reference laser. We calculated vibrational distribution of RbCs molecules in metastable ground state and corresponding transition probabilities to RbCs+ ion in (1)Σ+2 state. An enlarged PI spectrum with relative clear peaks is assigned to v=24–33 vibrational levels of molecular ion state. The method we used in PI spectrum analysis is also adoptable for other states of RbCs molecules or other kinds of molecules.