Ptychographic phase retrieval by applying hybrid input-output (HIO) iterations sequentially

We have designed a ptychographical algorithm (HIO-PIE) in which HIO (Hybrid Input-Output) iterations are applied for each probe position sequentially. Simulations indicated that HIO-PIE tends to outperform PIE (Ptychographical Iterative Engine) even in the presence of shot noise, especially when the number of probe positions is small. Thus, this adaptation may reduce the number of scan positions required for a successful image reconstruction, thereby relaxing the constraints on an experimental setup. In this article, experimental results obtained using an SLM (spatial light modulator) and visible laser light (633 nm) show that when few probe positions are used, HIO-PIE converges significantly faster than PIE.