Phase-difference amplification using a Sagnac interferometer

Phase difference enhancement with classical intensity interferometry

“…It is known that the technique of phase difference enhancement (or amplification) serves to increase sensitivity and accuracy in interferometric measurements [27]. Such a technique has been achieved by means of a nonlinearly processed hologram [27][28][29], a specific shearing interferometer using a conventional linear hologram [30][31][32], and a spatial light modulator (SLM) in place of a hologram [33][34][35]. However, all these methods so far proposed are rather cumbersome in the sense that chemical processing is required to produce a hologram or that two interferometric arrangements have to be precisely aligned in the case when an SLM is employed.…”