* 主讲人：Roger Proksch Adjunct Professor @ Group Chief Technical Officer, Oxford Instruments plc; Adjunct Professor, University of Tennessee, Knoxville
* 时间：2026年9月11日 10:00
* 地点：Room P1078, College of Science
## 主讲人简介
Roger Proksch, PhD – global AFM leader, CTO of Oxford Instruments, co-founder of Asylum Research, and adjunct professor at UT Knoxville. He holds a Ph.D. from Minnesota, worked at Digital Instruments, and co-founded Asylum in 1999, developing Cypher, Vero (R&D 100 winner 2024), and Jupiter. After Oxford’s 2012 acquisition, he led integration and growth. Author of 100+ papers (h-index 52), 39 US patents, >$250M revenue. Former APS chair, NASA Icy Worlds member, PFM co-founder. A visionary bridging academia and industry.
## 讲座简介
Most AFM measurements are limited by detector noise and bandwidth, not cantilever motion. Conventional optical beam deflection suffers from relatively high displacement-noise levels, often requiring filtering or resonant amplification that can obscure dynamics or perturb sensitive materials. In contrast, quadrature phase differential interferometry (QPDI) achieves a noise floor well below the Brownian motion of many AFM cantilevers, enabling previously inaccessible measurements. First, improved noise performance uncovers hidden dynamics in ambient force-distance curves, and enables real-time contact resonance stiffness and dissipation mapping without extra actuation.Second, for Piezoresponse force microscopy (PFM), conventional optical beam-deflection PFM requires high AC drive voltage to overcome noise, which introduces adverse effects, especially for emerging low-voltage weak-response materials. We propose interferometrically detected resonance-enhanced dual AC resonance tracking (iDART), which combines QPDI's femtometer-scale sensitivity with contact-resonance amplification and dual-frequency tracking. This method achieves ≥10× signal-to-noise improvement over leading PFM modalities, enabling imaging and switching spectroscopy at greatly reduced excitation levels.
