Dynamic Light Scattering Instrumentation Using Field Programmable Gate Array-based Digital Signal Processing

An existing low-cost FPGA-based processing platform will be demonstrated with fiber-coupling to single-photon detectors, to perform photon-arrival time stamping with <25-ps jitter. Multi-channel auto/cross-correlation will be implemented along with dynamic light scattering (DLS) analysis algorithms for fitting multiple diffusion models to measured samples. Existing Matlab and Simulink tools will be used to model the instrument, to perform design tradeoffs, and to develop a user interface for DLS experiments. An instrument specification will be finalized, including any necessary sensor and laser configuration and control interfaces, host I/O, memory, and identification of the features necessary for compatibility with the flow reactor and other measurement systems. The DLS algorithms will then be demonstrated using simulated and existing data. A small-sized FPGA-based printed circuit board including a microcontroller and USB and Gigabit-Ethernet communications will be fabricated, the VHDL code will be implemented, and the DLS processing platform will be demonstrated, characterized, and delivered to NIST.