September 2016 Academic Research Highlights

Axsun's swept laser products lead the way in not only commercial SS-OCT systems, but also in cutting edge academic research.  Here are some highlights of recent publications relating to a variety of novel OCT and non-OCT approaches, all based in part on Axsun's swept laser platform.

 

OCT Angiography

OCT Angiography (OCTA) to visualize retinal and choroidal vasculature is a burgeoning area of ophthalmic research and patient care in the past few years.  Gorczynska and colleagues at UC-Davis recently published a thorough comparison of several OCTA processing methods using an Axsun laser.

Iwona Gorczynska, Justin V. Migacz, Robert J. Zawadzki, Arlie G. Capps, and John S. Werner, "Comparison of amplitude-decorrelation, speckle-variance and phase-variance OCT angiography methods for imaging the human retina and choroid," Biomed. Opt. Express 7, 911-942 (2016)

Liu and colleagues in the Huang group at OHSU introduced split-spectrum phase-gradient OCTA and compared several processing methods using both a SD-OCT system and a SS-OCT system based on Axsun's 200kHz swept laser. 

Gangjun Liu, Yali Jia, Alex D. Pechauer, Rahul Chandwani, and David Huang, "Split-spectrum phase-gradient optical coherence tomography angiography," Biomed. Opt. Express 7, 2943-2954 (2016)

Finally, Ginner and colleagues in the Leitgeb group in Vienna published a wide-field swept-source OCTA approach at 400kHz based on spectral splitting, a clever way to tradeoff axial resolution to gain imaging speed.

Ginner, L.; Blatter, C.; Fechtig, D.; Schmoll, T.; Gröschl, M.; Leitgeb, R.A. Wide-Field OCT Angiography at 400 KHz Utilizing Spectral Splitting. Photonics 2014, 1, 369-379.

 

Polarization-Sensitive OCT in a Needle Probe

A successful integration of imaging needle probe technology from the Sampson group at Western Australia with PS-OCT technology from the Bouma group at Wellman/MGH was published in Nature Scientific Reports.  The team demonstrated impressive three-dimensional birefringence images of excised breast tumors, with a long-term goal to differentiate between healthy, collagen-rich, and cancerous tissue in an intraoperative fashion. 

Villiger, M. et al. Deep tissue volume imaging of birefringence through fibre-optic needle probes for the delineation of breast tumour. Sci. Rep. 6, 28771 (2016)

 

Master-Slave OCT and Coherence Revival

Utilizing the coherence revival properties of external cavity tunable lasers has been an interesting area of research since these lasers arrived on the scene.  Dr. Bradu et al at the University of Kent have invented a clever new approach for achieving long axial range in a simplified fashion with coherence revival.

Adrian Bradu, Sylvain Rivet, and Adrian Podoleanu, "Master/slave interferometry – ideal tool for coherence revival swept source optical coherence tomography," Biomed. Opt. Express 7, 2453-2468 (2016)

 

Scanning Laser Polarimetry

In a departure from using Axsun's swept lasers for Swept-Source OCT, the Le Grand group in Brest, France has demonstrated the potential of a new high-speed laser scanning Mueller microscope concept.

A. Le Gratiet ; M. Dubreuil ; S. Rivet and Y. Le Grand "100 kHz Mueller polarimeter for laser scanning polarimetric microscopy", Proc. SPIE 9887, Biophotonics: Photonic Solutions for Better Health Care V, 988724 (April 27, 2016); doi:10.1117/12.2227118

Aymeric Le Gratiet, Sylvain Rivet, Matthieu Dubreuil, and Yann Le Grand, "100  kHz Mueller polarimeter in reflection configuration," Opt. Lett. 40, 645-648 (2015)