Future neutrino detectors will be larger, and yet require higher resolution. Improvements in our understanding and calibration of detector processes need to go hand in hand new instrument development. Our neutrino detector R&D is aimed at better measurements of scintillator response, wavelength shifter response, including extending to vacuum ultraviolet (VUV) wavelengths, and characterization of new technologies such as water soluble liquid scintillator. Much of this R&D is also of interest to future Dark Matter experiments. Using a Compton polarimeter, we have measured the nonlinearity of response of organic scintillators such as used in Daya Bay, which permits improved simulation and lower systematics. This technique is now available to characterize other media, such as liquid xenon of interest to Dark Matter searches. Future work includes investigation of event reconstruction in large cryogenic neutrino detectors. This includes investigation of advanced reconstruction techniques using machine learning that may run on dedicated hardware, as well as investigation of large are pixellated readout instead of wire planes.