The IR antenna pair coupled sensor element and its potential application in wavefront sensing

A single IR antenna-coupled square-law sensor does not preserve the phase of the radiation field. We considered an IR radiation detector element in which the square-law sensor is coupled with a pair of IR dipole antennas, the simplest coherently interconnected IR antenna array with the potential of preserving phase information. The circuit equivalent model is employed for analyzing the response features of an element to a tilted incident plane wave. The analytical results show that the response of such an element contains the phase difference information of incident radiation field at the positions of the two antennas and can be characterized by its induced phase shift, ΔΔ, and the “visibility” of its oscillation profile, κκ. In addition, the numerical computations for the case of shifted square-law detectors shows that ΔΔ and κκ are strongly affected by, and therefore can be controlled by the electric and geometrical parameters of the antenna element system. Furthermore, a method of using the response measurement of such elements to retrieve the wavefront phase information is also provided.