Wide field amplitude and phase confocal microscope with parallel phase stepping

Abstract

We describe a wide field phase sensitive confocal microscope based on correlation between speckles. In this system, parallel optical phase stepping provides for the simultaneous capture of four interferograms using a single camera, giving the system the potential to operate at high speed. The interferograms are mapped to a common frame of reference, removing any relative distortion in the process, so that phase, amplitude, and interference efficiency images can be obtained. We use a new phase stepping algorithm that accounts for the unequal phase steps and unbalanced beam amplitudes that are a consequence of the optical arrangement. Experimental results to show that the system operates as a wide field amplitude and phase confocal system are presented.

Full-Field and Single-Shot Full-Field Optical Coherence Tomography: A Novel Technique for Biomedical Imaging Applications

“…Several types of simultaneous phase-shifting method have been developed over the years, and these techniques utilize conventional beam splitters and polarization optics to produce three or four phase shifted images on a singleor multi-charge-coupled device (CCD) for simultaneous acquisition [56][57][58][59]. Figure 4 shows the basic schemes of simultaneous interferometry.…”

Quantitative optical microscope with enhanced resolution using a pixelated liquid crystal spatial light modulator

“…The spot diameter, d , at the diffuser can be reduced significantly without increasing the speckle noise using a double diffuser arrangement. By placing two diffusers next to each other (one can be stationary), the speckle speed at the sample surface can be increased dramatically (Sawyer et al ., 2001), thus ensuring a sufficient number of speckles averaged within the exposure time of the CCD camera. However, in our system, a double diffuser arrangement was not possible owing to the compromise in light output; therefore, to avoid excessive speckle noise, a compromise was made by using a larger light spot diameter on the diffuser.…”

Indeterminacy of amplitude and phase variables in classical dynamical systems: The harmonic oscillator

“…There is also a widespread use of these variables in detection and analysis of experimental data. Some recent examples in observational astronomy are cosmic microwave background maps [23] and correlations in the solar cycle [24]; in nonlinear optics: ultrashort pulse two-photon absorption [25], optical amplifiers [26] and time-dependent optical signals [27]; in physical optics: interferometric noise measurements [28] and standards [29]; in scientific instruments: optical design of confocal microscopes [30], apodization of telescope pupils [31] and analysis of reflectance spectra [32].…”