Testing. The Orenstein group focuses on the development and application of advanced optical techniques to probe quantum materials. We have made major contributions to methods of optical spectroscopy across the electromagnetic spectrum, from the development of time-domain THz spectroscopy as a probe high-Tc superconductors, to transient grating spectroscopy using visible light as a probe of spin propagation in two-dimensional electron systems. However, we don’t go it alone, as the diversity and complexity of quantum materials require a multidisciplinary and multi-investigator approach. Our optics lab is part of the Quantum Materials Group, which is a network of UC Berkeley Department of Physics faculty and LBNL staff scientists whose expertise spans the spectrum of synthesis and characterization techniques. In addition, we are a member of the Spin Physics Group at the Materials Science Division at SLAC.