Identifying the subwavelength-aperture-width variation in the far field with tunable asymmetrically-embedded-aperture interferometer configuration

A tunable asymmetrically-embedded-aperture interferometer configuration is proposed to enhance the measurement sensitivity of subwavelength variation. With this configuration, an aperture of reference was posited asymmetrically, relative to the test aperture, that exhibited subwavelength variation. By a shift in the relative position of the reference aperture, the detection sensitivity of measuring the subwavelength variation in the far field can be enhanced to a desired value at any specific detection width. We discuss the underlying mechanism of optimization and address the difference between the embedded-aperture interferometry and tunable asymmetrically-embedded-aperture interferometry with respect to tolerance.