Design and Implementation Guidelines for a Modular Spectral-Domain Optical Coherence Tomography Scanner

Abstract

In the past decades, spectral-domain optical coherence tomography (SD-OCT) has transformed into a widely popular imaging technology which is used in many research and clinical applications. Despite such fast growth in the field, the technology has not been readily accessible to many research laboratories either due to the cost or inflexibility of the commercially available systems or due to the lack of essential knowledge in the field of optics to develop custom-made scanners that suit specific applications. This paper aims to provide a detailed discussion on the design and development process of a typical SD-OCT scanner. The effects of multiple design parameters, for the main optical and optomechanical components, on the overall performance of the imaging system are analyzed and discussions are provided to serve as a guideline for the development of a custom SD-OCT system. While this article can be generalized for different applications, we will demonstrate the design of a SD-OCT system and representative results for in vivo brain imaging. We explain procedures to measure the axial and transversal resolutions and field of view of the system and to understand the discrepancies between the experimental and theoretical values. The specific aim of this piece is to facilitate the process of constructing custom-made SD-OCT scanners for research groups with minimum understanding of concepts in optical design and medical imaging.

Optogenetic interrogation of neurovascular coupling in the cerebral cortex of transgenic mice

“…For our experiments, we developed a spectral-domain optical coherence tomography (OCT) scanner [22][23][24] and extra comp onents were integrated to simultaneously perform fluorescence imaging and patterned optogenetic stimulation (figure 1(a)) ( [13,25,26]).…”

“…The implemented spectral-domain OCT scanner uses a low coherence light source (central wavelength 1300 nm, bandwidth >170 nm, total power 10 mW, Thorlabs, NJ, USA) and a 10x OCT objective lens (LSM02, Thorlabs, NJ, USA) to achieve axial and lateral resolutions of ∼4.4 μm and ∼5.1 μm, respectively [26]. A scan/tube lens mechanism is designed and used to open up the space before the back focal plane of the objective [25].…”

“…A scan/tube lens mechanism is designed and used to open up the space before the back focal plane of the objective [25]. This space is used to install a dichroic beamsplitter (D1, FF875, Semrock) before the OCT objective lens to combine the OCT light and visible beam pathways [26]. The visible path is devoted to the delivery of optogenetic stimulation light pulses and/or fluorescence excitation beam.…”

Inpainting for Saturation Artifacts in Optical Coherence Tomography Using Dictionary-Based Sparse Representation

“…In SD-OCT, CCD, an array of photodetectors, measures interference signals in a range of specific frequency domain [ 18 ], [ 19 ]. The maximum amount of charges that a single pixel can store is defined as the full well capacity of a spectrometer [ 20 ].…”

Jitter Correction and SNR Improvement of A-Scan Signal Using Wavelet Denoising and Signal Averaging for a Portable Time-Domain Optical Coherence Tomography System

“…An OCT system technology can be a timedomain OCT (TD-OCT) and frequency-domain OCT (FD-OCT). The main difference between the two is that the former uses a scanning mechanism to modulate the optical length of the reference path continuously and the intensity of the interference signal is maximum when the sample and reference path are equal, whereas the latter has a fixed mirror that generate images by analyzing the spectral pattern of the collected interferograms generated by combining the reflected lights from the reference and the sample arms [7].…”