Ultrahigh resolution optical coherence tomography using a superluminescent light source

Abstract

A superluminescent Ti:Al 2 O 3 crystal is demonstrated as a light source for ultrahigh resolution optical coherence tomography (OCT). Single spatial mode, fiber coupled output powers of~40 µW can be generated with 138 nm bandwidth using a 5 W frequency doubled, diode pumped laser, pumping a thin Ti:Al 2 O 3 crystal. Ultrahigh resolution OCT imaging is demonstrated with 2.2 µm axial resolution in air, or 1.7 µm in tissue, with >86 dB sensitivity. This light source provides a simple and robust alternative to femtosecond lasers for ultrahigh resolution OCT imaging.

Performance of ar/sup +/ -milled ti:sapphire rib waveguides as single transverse-mode broadband fluorescence sources

“…Approximately 2-m resolution has been demonstrated using a Ti:sapphire bulk fluorescent emitter [3] and slow in vivo scanning can be performed in this way [4]. However, these sources are insufficient for fast-scanning OCT due to their low brightness.…”

Broadband superluminescent diode–based ultrahigh resolution optical coherence tomography for ophthalmic imaging

“…Ti:sapphire lasers have been used for ultrahigh resolution OCT. 22,27,28 Based on the extremely broad bandwidth of spectra in the 800-nm wavelength region, OCT using Ti:sapphire lasers as a light source achieve the highest resolution of about 1 μm. 24,[29][30][31][32] However, the application of a Ti:sapphire laser in commercial OCT is limited because of their complexity and high cost. SLD is widely used in commercial OCT devices as the light source because of its relatively low cost compared with Ti:sapphire lasers and operation in different wavelength regions.…”

Single-transverse-mode Ti:sapphire rib waveguide laser

“…Compact fluorescence and laser devices based on Ti:sapphire in channel geometries are particularly interesting for applications in optical coherence tomography (OCT) [2] due to their high brightness and potential to provide fully diffraction-limited, near circular, singlemode beams which would allow integration with OCT fiber interferometric arrangements [3]. Moreover, a combination of Ti:sapphire channel waveguides with semiconductor saturable absorber mirrors (SESAM) and saturable Bragg reflector (SBR) technologies would open up the possibility to develop a compact, portable, broadly tunable laser with the potential to produce high-repetition-rate mode-locked pulses.…”