Hollow core electromagnetic coil

An augmented reality/virtual reality (AR/VR) system employs a tracking system for tracking one or more components of the AR/VR system using a generated electromagnetic (EM) field. The tracking system employs an EM coil for generating the EM field or, alternatively, sensing the EM field. The EM coil includes a core substrate and thin metal foil wrapped around the core substrate in three orthogonal axes. The EM coil is effectively "hollow" in that it weighs less than a conventional solid ferrite or ferrous core of comparable dimensions, either through the use of one or more openings formed in the core substrate, the use of a material less dense than ferrite or ferrous materials, the formation of the core substrate as a hollow framework, or a combination thereof. The resulting EM coil thus weighs less than conventional solid-core EM coils, thereby reducing user fatigue and the possibility of misalignment of the EM coil as a result from a drop impact of the device implementing the EM coil.