Based on our patent pending optical sensor design, the HVSS provides a means to reliably and precisely measure ultra-high voltage. The all-dielectric sensor configuration intrinsically eliminates the concern of arcing often associated with ultra-high voltage environments. It uniquely offers many advantageous features: accurate voltage measurement with zero phase shift and low noise, flat response through the 20th harmonic; lightweight; inductance-based self-powered build-in. The design is an all-in-one unit that can be directly mounted onto a high voltage conductor cable. Custom configurations are available, including fiber readout, and Bluetooth communication to an adjacent transmission unit.