Phase-conjugate optical coherence tomography

Quantum optical coherence tomography (Q-OCT) offers a factor-of-two improvement in axial resolution and the advantage of even-order dispersion cancellation when it is compared to conventional OCT (C-OCT). These features have been ascribed to the non-classical nature of the biphoton state employed in the former, as opposed to the classical state used in the latter. Phase-conjugate OCT (PC-OCT), introduced here, shows that non-classical light is not necessary to reap Q-OCT's advantages. PC-OCT uses classical-state signal and reference beams, which have a phase-sensitive cross-correlation, together with phase conjugation to achieve the axial resolution and even-order dispersion cancellation of Q-OCT with a signal-to-noise ratio that can be comparable to that of C-OCT.Comment: 4 pages, 3 figure

Gaussian-State Theory of Two-Photon Imaging

Biphoton states of signal and idler fields--obtained from spontaneous parametric downconversion (SPDC) in the low-brightness, low-flux regime--have been utilized in several quantum imaging configurations to exceed the resolution performance of conventional imagers that employ coherent-state or thermal light. Recent work--using the full Gaussian-state description of SPDC--has shown that the same resolution performance seen in quantum optical coherence tomography and the same imaging characteristics found in quantum ghost imaging can be realized by classical-state imagers that make use of phase-sensitive cross correlations. This paper extends the Gaussian-state analysis to two additional biphoton-state quantum imaging scenarios: far field diffraction-pattern imaging; and broadband thin-lens imaging. It is shown that the spatial resolution behavior in both cases is controlled by the nonzero phase-sensitive cross correlation between the signal and idler fields. Thus, the same resolution can be achieved in these two configurations with classical-state signal and idler fields possessing a nonzero phase-sensitive cross correlation.Comment: 14 pages, 5 figure

Aplikasi Fotogrammetri Rentang Dekat Untuk Pemodelan 3d Gedung a Lawang Sewu

[Close Range Photogrammetry Application for 3D Modelling of Lawang Sewu Building A] Close range photogrammetry is a one of photogrammetry applications. It can be used for the object measurement that is less than 100 meters. It also usualy used in 3D modeling of buildings, vehicles or bridges etc. In this final task, close range photogrammetry method was used for 3D modeling of Lawang Sewu Building A using non-metric digital camera. Initially, the camera must through of calibration process to determine the camera internal parameters. The process of calibration and data processing in this final task are using PhotoModeler Scanner v.7 2013 software. Phase of buildings modeling contain of marking and referencing, calculating and 3D modeling, transformation of 3D coordinate and visualization of 3D models. The data used are the photos that taken all around Lawang Sewu building A. The final results in this research are 3D model of Lawang Sewu Building A. Testing of the results in 3D modelling processing were done by comparing the 3D model distance referenced to Electronic Total Station measurement and statistics test with level of trust 95%. The statistics test in this research shows that there are no significant difference between ETS measurement