title: Large step-phase measurement by a reduced-phase triple-illumination interferometer.
abstract: We present a reduced-phase triple-illumination interferometer (RPTII) as a novel single-shot technique to increase the precision of dual-illumination optical phase unwrapping techniques. The technique employs two measurement ranges to record both low-precision unwrapped and high-precision wrapped phases. To unwrap the high-precision phase, a hierarchical optical phase unwrapping algorithm is used with the low-precision unwrapped phase. The feasibility of this technique is demonstrated by measuring a stepped object with a height 2100 times greater than the wavelength of the source. The phase is reconstructed without applying any numerical unwrapping algorithms, and its noise level is decreased by a factor of ten.
authors.forename: Behnam
authors.initials: B
authors.lastname: Tayebi
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Jafarfard
authors.forename: Farnaz
authors.initials: F
authors.lastname: Sharif
authors.forename: Young Sik
authors.initials: YS
authors.lastname: Song
authors.forename: Dongsoo
authors.initials: D
authors.lastname: Har
authors.forename: Dug Young
authors.initials: DY
authors.lastname: Kim