Self-Referenced Subcycle Metrology of Quantum Fields

A new time-domain method for subcycle metrology of quantum electric fields using a combination of a third order nonlinear optical process and homodyne detection with a local oscillator (LO) field is proposed and analyzed. The new method enables isolation of intrinsically weak quantum noise contribution by subtraction of the shot noise of the LO on a pulse-by-pulse basis. Together with the centro-symmetric character of the nonlinearity, this method unlocks novel opportunities toward terahertz and mid-infrared quantum field metrologies.

Automated summary

A new time-domain method is proposed and analyzed for subcycle metrology of quantum electric fields, which involves a combination of a third order nonlinear optical process and homodyne detection with a local oscillator field. The method allows isolation of weak quantum noise contribution by subtracting the shot noise of the local oscillator on a pulse-by-pulse basis. With the centro-symmetric character of the nonlinearity, this method presents novel opportunities for terahertz and mid-infrared quantum field metrologies.