Recovering distance information in spectral domain interferometry

Abstract

This work evaluates the performance of the Complex Master Slave (CMS) method, that processes the spectra at the interferometer output of a spectral domain interferometry device without involving Fourier transforms (FT) after data acquisition. Reliability and performance of CMS are compared side by side with the conventional method based on FT, phase calibration with dispersion compensation (PCDC). We demonstrate that both methods provide similar results in terms of resolution and sensitivity drop-off. The mathematical operations required to produce CMS results are highly parallelizable, allowing real-time, simultaneous delivery of data from several points of different optical path differences in the interferometer, not possible via PCDC.

Optical Interferometric Fringe Pattern-Incorporated Spectrum Calibration Technique for Enhanced Sensitivity of Spectral Domain Optical Coherence Tomography

“…Hence, the results of Section 3.4 qualitatively verified that the developed calibration method performed over the entire spectrum remarkably enhanced the visualization of microstructural features of transparent mediums, such as anterior and posterior vitreous owing to the enhanced depth-visualizing sensitivity and image resolution of deep structures. Similar to previously reported methods [37][38][39][40][41][42], the developed fringe pattern-incorporated spectrum calibration method is applicable to enhance the sensitivity of the SD-OCT system and to compensate the dispersion mismatch as a simultaneous approach. Indeed, it relies on intensity information of the interferometric fringe signals, and the adjustable intensity weight (multiplication factor) confirmed the simple functionality and lower complexity of the proposed method compared to conventional methods.…”

“…Additionally, a full-range visualizing technique was integrated along with spectral and dispersion calibration, which enhances the OCT providing a large depth range [38]. To eliminate the necessity of linearization, a dual interferometer-based (master and slave interferometers) approach was developed to operate with a sensitivity similar to SD-OCT providing signal from a single point in depth [39,40] and a similarly complex master slave OCT method was performed to process the interferometer spectrum without Fourier transformation. Semi-automatic spectral mapping is another technique, which was acquired using dual spectrometers, where a set of calibration interference fringes has to be acquired from both spectrometers [41,42].…”

Developments on using supercontinuum sources for high resolution multi-imaging instruments for biomedical applications

“…To correct for non-linearities, compensate for the dispersion left uncompensated in the interferometer which can be significant when using wide spectral bandwidths, and produce the sensitivity drop-off, we employed the Master-Slave technique [5][6][7]. By using it, we matched the theoretical values of the axial resolution over a quite large axial range (1.5 mm) as illustrated in Fig.…”

Lensless fiber-deployed low-coherence interferometer for in-situ measurements in nonideal environments

“…Methods of circumventing remapping captured spectra through various computational techniques have also been investigated in literature. [31][32][33] The approach taken in this work is similar to that presented for automatic calibration 15 and interferometric methods, [23][24][25] relying on the knowledge that for a singular reflector, and while operating in a common-path configuration negating the requirement for dispersion compensation, the interference fringes will be evenly spaced in k-space. By using zero-crossing detection, fringe spacing as a function of pixel number is obtained from which a mapping relationship between linear in λ and linear in k-space can be created, this allows interpolation of the data using a B-spline interpolation to create an evenly sampled dataset in k-space before performing an FFT.…”