US Patent 12085719 Head mounted device with terahertz tracking

Terahertz sensing in this disclosure involves the use of at least one terahertz signal that is transmitted towards an object. At least one return terahertz signal is reflected from the object. The return terahertz signal(s) may be analyzed to determine one or more parameters, such as phase, frequency, amplitude, spectral profile, time of flight (TOF) etc. associated with the return terahertz signal(s). Based on the parameter(s), a portion of the object impinged upon by the transmit terahertz signal(s) and which reflected the return terahertz signal(s), and the state of the object/portion, can be identified. The identification of the portion and its state can be used in eye tracking implementations.