Dynamic Light Scattering (DLS) characterizes particles from nanometers to micrometers by analyzing intensity fluctuations in scattered light caused by Brownian motion. Correlation timing electronics convert intensity data into correlation functions and diffusion coefficients, which yield hydrodynamic radius via the Stokes-Einstein equation. Multiangle DLS measurements provide robust size distributions for polydisperse samples using Cumulant or CONTIN analysis methods.
Photon Number Resolution (PNR), the ability to distinguish how many photons are impinging on a single photon detector within a defined time window, can be achieved through pseudo-PNR, where photon numbers are statistically inferred, or intrinsic PNR, where photon numbers are measured directly from the detector signal.
Time-Correlated Single Photon Counting (TCSPC) is a technique that measures the precise arrival times of individual photons emitted by a sample following an excitation with a pulsed light source.