English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In conventional OCT, broadband light sources are generally utilized to obtainhigh axial resolution due to their low temporal coherence (TC) length. Purelymonochromatic (i.e., high TC length) light sources like laser cannot beimplemented to acquire high resolution optically sectioned images of thespecimen. Contrary to this, pseudo thermal light source having high TC and lowspatial coherence (SC) property can be employed to achieve high axialresolution comparable to broadband light source. In the present letter, apseudo thermal light source is synthesized by passing a purely monochromaticlaser beam through a rotating diffuser. The longitudinal coherence (LC)property of the pseudo thermal light source is studied as a function of sourcesize and TC length. The LC length of the synthesized light source decreased asthe source size increased. It is found that LC length of such light sourcebecomes independent of the parent laser TC length for source size of greaterthan or equal to 3.3 mm and become almost constant at around 30 micron for boththe lasers. Thus any monochromatic laser light source can be utilized to obtainhigh axial resolution in OCT system irrespective of its TC length. The maximumachievable axial resolution is found to be equal to 650 nm corresponding to 1.2numerical aperture (NA) objective lens at 632 nm wavelength. The findingselucidate that pseudo thermal source being monochromatic in nature can improvethe performance of existing OCT systems significantly.

Study of longitudinal coherence properties of pseudo thermal light source as a function of source size and temporal coherence