Two National metrology institutes in collaboration, NIST (P.A. Williams, K.A. Rogers, National Institute of Standards and Technology, USA) and CMI (M. Šmíd, G. Porrovecchio, Czech Metrology Institute, Czech Republic) demonstrated an alternative method of SI-traceable non-destructive (essentially non-absorbing) measurement of individual laser pulse energy pulse-by-pulse. The portable Radiation Pressure Power Meter (RPPM) developed by NIST was used in conjunction with the cutting-edge fast pulse photodetector developed by CMI. This is the first time that the absolute energy of laser pulses have been directly measured with SI-traceability to the unit of mass. More information is available here. See also https://www.hilase.cz/en/high-accuracy-measurement-of-bivoj-pulse-energy-usi.