Fig. also plots the emission intensity, INP (photons/second/sr, integrated between 600 -1600 nm ) and the laser power (mW) required to heat the NP to the TNP setpoint values. In this example, both were nearly constant during each constant TNP period, indicating that NP optical properties (near-IR emissivity and 532 nm absorptivity) were not significantly altered by the heating and modest mass loss in this experiment.