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MM: Fachverband Metall- und Materialphysik

MM 52: Topical Session: In Situ and Multimodal Microscopy in Materials Physics II

MM 52.3: Talk

Thursday, March 21, 2024, 11:00–11:15, C 130

Interference Gating - A Novel Shutter Mechanism for Time-Resolved Holography — •Tolga Wagner, Hüseyin Çelik, Simon Gaebel, Tore Niermann, and Michael Lehmann — Technische Universität Berlin, Germany

Common shutter mechanisms for realizing time-resolved imaging are usually based either on blocking the intensity of the radiation used (e.g. stroboscopic illumination) or on the fast readout time of modern detectors. For holographic investigations, which are based on the recording and reconstruction of interference patterns, a completely new type of gating mechanism is now available: interference gating (iGate).

The basic idea of iGate is a synchronized destruction of the interference pattern, realized by introducing random phase shifts to the wave, for a defined period of time during a holographic acquisition. The holographic reconstruction process acts as a temporal filter that only retains the information of the undisturbed interferogram outside this period. Since the acquisition of interference patterns is in general very susceptible to external disturbances, a targeted destruction of the interference pattern is rather easy to realize and the interference gating as a method becomes interesting in research areas, in which common shutter mechanisms are difficult to be implemented.

In transmission electron microscopy (TEM), for instance, iGate can be retrofitted with minimal technical effort in almost any existing instrument, hence transforming them into time-resolved investigation techniques at nanosecond timescales with nanometer spatial resolution.

Keywords: Time Resolved Electron Holography; Ultra-fast Transmission Electron Microscopy; Nanosecond Observation