Biomedical subjects

Daniel J Kane

Publications and source records attributed to Daniel J Kane.

4 recordsLinked to original sources

PubMed2006

Resolving the complex conjugate ambiguity in Fourier-domain OCT by harmonic lock-in detection of the spectral interferogram.

A method of resolving the complex conjugate ambiguity in Fourier-domain OCT is described. The complex differential spectral interferogram is obtained by simultaneous acquisition of the first and second harmonics of the ac component of the phase-modulated interferogram. The harmonics represent the imaginary and real parts of the interferogram, respectively. The complex conjugate rejection ratio is found to be at least 45 dB and is limited by background noise.

Algorithms↗

PubMed2003

Common-path interferometer for frequency-domain optical coherence tomography.

A Michelson-type spectral interferometer that uses a common beam path for the reference and the sample arms is described. This optical arrangement is more compact and stable than the more commonly used dual-arm interferometer and is well suited for frequency-domain optical coherence tomography of biological samples. With a 16-bit CCD camera, the instrument has sufficient dynamic range and resolution for imaging to depths of 2 mm in scattering biological materials. Images obtained with this spectral interferometer are presented, including cross-sectional images in a Xenopus laevis tadpole.

Abdomen↗

PubMed2003

Differential spectral interferometry: an imaging technique for biomedical applications.

Differential spectral interferometry (DSI), a novel method of biomedical imaging that combines the high dynamic range of optical coherence tomography (OCT) with inherently parallel low-bandwidth image acquisition of spectral interferometry (SI), is described. DSI efficiently removes the deleterious dc background inherent in SI measurements while maintaining the parallel nature of SI. We demonstrate DSI on both synthetic and biological samples. Because DSI preserves the low-bandwidth, parallel nature of SI, it is competitive with OCT for biomedical applications in terms of image quality and acquisition rate.

Anatomy, Cross-Sectional↗

PubMed2003

Real-time inversion of polarization gate frequency-resolved optical gating spectrograms.

Frequency-resolved optical gating (FROG) is a technique used to measure the intensity and phase of ultrashort laser pulses through the optical construction of a spectrogram of the pulse. To obtain quantitative information about the pulse from its spectrogram, an iterative two-dimensional phase retrieval algorithm must be used. Current algorithms are quite robust but retrieval of all the pulse information can be slow. Previous real-time FROG trace inversion work focused on second-harmonic-generation FROG, which has an ambiguity in the direction of time, and required digital signal processors (DSPs). We develop a simplified real-time FROG device based on a single-shot geometry that no longer requires DSPs. We use it and apply the principal component generalized projections algorithm to invert polarization gate FROG traces at rates as high as 20 Hz.

Journal Article↗