Intra-cavity photodetachment microscopy and the electron affinity of germanium

Photodetachment microscopy is performed inside an optical cavity, on an ion beam and with an optical mode narrow enough not to blur out the output electron interferogram. This setting is used for an updated measurement of the electron affinity of germanium. Amplification of the photodetachment probability obtained in an optical cavity also opens the way to photodetachment microscopy with a p electron wave, even though photodetachment cross-sections are reduced considerably in this case, when compared to s-wave detachment, by the centrifugal barrier.