Modelling for Spectral Domain Optical Coherence Tomography (SD-OCT) System

Abstract

Optical Coherence Tomography (OCT), a revolutionary technology was initially developed for imaging retinas to investigate various eye diseases like glaucoma, diabetic retinopathy etc. It later found acceptance for its non-invasive nature in other bio medical applications like cardiology, dermatology etc. It is very similar to ultrasound in nature; the only difference is usage of light waves in place of sound waves and it offers higher axial resolution in comparison with most of other existing technologies. The technology behind SD-OCT is Michelson interferometry, which offers the usage of Super Luminescent Diode (SLD) source as low temporal coherent source with broad bandwidth to measure its absorption/scattering through the sample specimen. In the following paper, we depict the model of SD-OCT system. The spectral response of the source and the output generated waveforms show the response of the model in respect to the actual hardware. LabVIEW software could generate the graphical user interface. The samples were used on the basis of their refractive indices. The maximum depth obtained depends on the number of pixels. Depth of up to 0.5 mm can be obtained with 127 pixels and 1.7 mm with 400 pixels with axial resolution as 7.75 µm for 100 nm bandwidth 1310 nm SLD source. Simulation results at 632.8, 840 and 1310 nm are compared and discussed.