OCT resolution enhancement using long-period fiber grating and erbium-doped fiber

Abstract

We proposed a technique to improve OCT resolution using LPG and EDF. The proposed technique improves the resolution of OCT by reshaping the spectrum of ASE source into Gaussian-like form. The ASE source has a strong characteristic peak due to erbium that is used for doping material in EDF. To reduce the peak-induced artifact to OCT image that may degrade image quality and distort inner structure information, LPG is used as a strong ASE peak rejection filter and EDF does a function of absorber when pumping power is not applied. Both of them can do spectral tailoring function properly so that modified source shape and sidelobe suppression can be performed. With the LPGassisted reshaping, we have enhanced the spatial resolution up to 5 times (~200 µm resolution was reduced to about 40 µm). With EDF absorber, we can obtain reshaped ASE source hence resolution was enhanced from 25 µm to less than 20 µm). The spatial resolution can be further enhanced by using cascaded LPGs or control of EDF parameters such as doping material, doping concentration, and the length of used EDF.

Determination of the Optical Properties of Basal Cancer Using OCT System

“…However, there is also a demand for gaining insight into functional parameters of tissue, such as the blood oxygen content. With OCT, we can diagnose small segments of tissue as opposed to most of other imaging modalities that can scan the whole organ; image can be acquired in vivo and in real time without loss of information for unknown sample structure [20]. In addition, it also precludes the need for surgical biopsies and hence avoids discomfort and bleeding of biopsies [21].…”