With the progress of achieving diffraction-limited X-ray focus, ptychography offers a unique and powerful tool to provide quantitative reconstruction of the complex-valued wavefront of a focused beam. Propagation of the reconstructed wavefront essentially describes complete performance characterization of the optics. We will present the accumulated efforts at NSLS-II on exploring the capability of ptychography to quantify focusing performance of a variety of hard X-ray optics, including K-B mirrors, zone plates, multilayer Laue lenses [1-3]. Presentation will also elaborate on our recent development of monolithically bonded MLLs as a signal optical component for scanning probe microscope applications [4,5].
 X. Huang, et al., “Quantitative X-ray wavefront measurements of Fresnel zone plate and K-B mirrors using phase retrieval”, Optics Express, 20, 24038-24048 (2012).
 X. Huang, et al., “11 nm hard X-ray focus from a large-aperture multilayer Laue lens”, Scientific Reports, 3, 3562 (2013).
 X. Huang, et al., “Achieving hard X-ray nanofocusing using a wedged multilayer Laue lens”, Optics Express, 23, 12496-12507 (2015).
 E. Nazaretski, et al., “Development and characterization of monolithic multilayer Laue lens nanofocusing optics"”, Applied Physics Letters, 108, 261102 (2016).
 X. Huang, et al., “Hard x-ray scanning imaging achieved with bonded multilayer Laue lenses”, submitted, (2017).
Thermoelectric oxide nanofibers prepared by electrospinning are expected to have reduced thermal conductivity when compared to bulk samples. Measurements of nanofibers’ thermal conductivity is challenging since it involves sophisticated sample preparation methods. In this work, we present a novel method suitable for measurements of thermal conductivity in a single nanofiber. A microelectro-mechanical (MEMS) device has been designed and fabricated to perform thermal conductivity measurements on a single nanofiber. A special Si template was designed to collect and transfer individual nanofibers onto a MEMS device. Pt was deposited by Focused Ion Beam to reduce the effective length of a prepared nanofiber. A single La<sub>0.95</sub>Sr<sub>0.05</sub>CoO<sub>3</sub> nanofiber with a diameter of 140 nm was studied and characterized using this approach. Measured thermal conductivity of a nanofiber was determined to be 0.7 W/m•K, which is 23% of the value reported for bulk La<sub>0.95</sub>Sr<sub>0.05</sub>CoO<sub>3</sub> samples.