Comparison of electrostatic and photon pressure force references at the nanonewton level

This work describes a metrological comparison between nanonewton force references derived from an electrostatic force balance (EFB) and photon pressure from laser optical power in the 1 Watt range. An EFB is used to measure photon pressure force in the 10 nanonewton range from the reflection of a laser from a low (approximately 10−5) loss III–V semiconductor distributed Bragg reflector (DBR) mirror while the power of the reflected beam was simultaneously monitored with a traceable thermopile detector. This work demonstrates a method to link mass, force and laser power within the international system of units (SI) with explicit treatment of absorption, diffuse reflection, and a detailed uncertainty analysis. Additionally, it demonstrates a viable method to scale this force continuously using a pulsed laser technique while maintaining the constant thermal load necessary for precision measurement of nanonewton forces with a mechanical balance.