Phase-and-amplitude computer tomography

Phase-and-amplitude computer tomography

A tomographic technique is proposed for reconstruction under specified conditions of the three-dimensional distribution of complex refractive index in a sample from a single projection image per view angle, where the images display both absorption contrast and propagation-induced phase contrast. The algorithm achieves high numerical stability as a consequence of the complementary nature of the ...

Frequency domain optoacoustic tomography using amplitude and phase

We introduce optoacoustic tomographic imaging using intensity modulated light sources and collecting amplitude and phase information in the frequency domain. Imaging is performed at multiple modulation frequencies. The forward modeling uses the Green's function solution to the pressure wave equation in frequency domain and the resulting inverse problem is solved using regularized least squares ...

Full phase and amplitude control in computer-generated holography.

We report what we believe to be the first realization of a computer-generated complex-valued hologram recorded in a single film of photoactive polymer. Complex-valued holograms give rise to a diffracted optical field with control over its amplitude and phase. The holograms are generated by a one-step direct laser writing process in which a spatial light modulator (SLM) is imaged onto a polymer ...

Instrumentation and calibration methods for the multichannel measurement of phase and amplitude in optical tomography

Amplitude and Frequency/Phase Modulation

I always had difficulties in understanding frequency modulation (FM) and its frequency spectrum. Even for the pure tone modulation, the FM spectrum consists of an infinite number of sidebands whose signs change from one sideband to the next one and whose amplitudes are given by the horrible Bessel functions. . . I work for Zurich Instruments, a Swiss maker of lock-in amplifiers and it has becom...