Ultrahigh-Resolution Optical Coherence Tomography with LED-Phosphor-Based Broadband Light Source

Abstract

This study proposed and demonstrated the potential use of LED phosphors as a simple light source for ultrahigh-resolution spectral-domain optical coherence tomography (SD-OCT) in the visible regime. Excited by a 405 nm diode laser, broadband spontaneous emission from three different LED phosphors was generated. The best axial resolution was 1.7 µm in air, and finally, corresponding three-dimensional (3D) ultrahigh-resolution SD-OCT imaging was performed with the proposed broadband light source.

Supercontinuum as a light source for miniaturized endoscopes

“…To take better advantages of imaging CMOS sensors, the corresponding illumination is equally critical. In the last decade, LEDs, with their compactness, long lifetime, high efficiency and high brightness, have gradually replaced halogen and xenon arc lamps in many critical medical illuminations [1,2]. LED based illumination is often carried out with conventional fiber bundle coupling [3] or directly with miniaturized LED chips packaged in the distal end of a camera module.…”

“…However, the emergence of ultra-compact CMOS image sensors, with die size as small as 0.7 x 0.7 mm 2 [4], would call for further innovation in endoscopy illumination so that the footprint of the camera module can fully utilize the ultra-compactness of the CMOS sensors [5][6][7][8][9]. Fiber bundle coupling or packaged LED chips in the distal end, usually of a few millimeters square in size, would be too large for such a purpose.…”