The SuperK GAUSS is a dual-output filter that transforms the wide spectral bandwidth of the SuperK EXTREME supercontinuum lasers and provides a Gaussian-like spectrum.  For OCT, the SuperK GAUSS provides two high power spectral outputs centered at 800nm and 1300nm, with bandwidths of up to 200nm, through single mode fiber using the SuperK Fiber Delivery system. Similar configurations are also available for WLI applications. The two Gaussian shaped spectra with can be used simultaneously but independed from each other due to its unique design.The SuperK GAUSS even allows the tuning of the center wavelength of each band over 200nm. Connecting the GAUSS to the SuperK EXTREME is very simple and shares the same Plug’n’Play platform common to all SuperK accessories.

Download the
SuperK GAUSS
datasheet

Applications: OCT and WLI

The wide spectral bandwidth of the SuperK GAUSS improves the axial resolution in Optical Coherence Tomography (OCT) and White Light Inteferometry (WLI) applications and in combination with the SuperK EXTREME supercontinuum laser, it provides a smooth spectrum, dramatically reducing the number of image artifacts resulting in images with both resolution and detail. 

The pitcture on the left shows the performance of an OCT system using the SuperK GAUSS with a SuperK supercontinuum laser, a superluminescent diode (SLD) and a femtosecond Ti:Sapphire laser, respectively. The SuperK GAUSS combination easily outperforms the SLD solutions and gives comparable performance to the more expensive and bulky Ti:Sapphire setup. 

Papers describing OCT using the SuperK supercontinuum source:

• Shear flow-induced optical inhomogeneity of blood assessed in vivo and in vitro by spectral domain optical coherence tomography in the 1.3 μm wavelength range By Peter Cimalla, Julia Walther, Matthaeus Mittasch and Edmund Koch 
• Ultra-high-resolution and ultra-high-sensitive optical micro-angiography based on supercontinuum light source By Zhongwei Zhi, Lin An, Jia Qin and Ruikang K. Wang, published in SPIE proceedings Vol. 7889 (2011).
• Non-invasive imaging and monitoring of rodent retina using simultaneous dual-band optical coherence tomography By Peter Cimalla, Anke Burkhardt, Julia Walther, Aline Hoefer, Dierk Wittig, Richard Funk and Edmund Koch, published in SPIE proceedings Vol. 7889 (2011).
• Simultaneous dual-band optical coherence tomography in the spectral domain for high resolution in vivo imaging By Peter Cimalla, Julia Walther, Mirko Mehner, Maximiliano Cuevas, and Edmund Koch, published in Optics Express, Vol. 17, Issue 22, pp. 19486-19500 (2009)  
• Phase-dispersion light scattering for quantitative size-imaging of spherical scatterers By Tasshi Dennis, Shellee D. Dyer, and Andrew Dienstfrey 

What is OCT?

Optical coherence tomography (OCT) is an optical signal acquisition and processing method. It captures micrometer-resolution, three-dimensional images from within optical scattering media (e.g., biological tissue). Optical coherence tomography is an interferometric technique, typically employing near-infrared light. The use of relatively long wavelength light allows it to penetrate into the scattering medium. Confocal microscopy, another similar technique, typically penetrates less deeply into the sample.

Depending on the properties of the light source (superluminescent diodes, ultrashort pulsed lasers and supercontinuum lasers have been employed), Optical coherence tomography has achieved sub-micrometer resolution (with very wide-spectrum sources emitting over a ~100 nm wavelength range)

Optical coherence tomography is one of a class of optical tomographic techniques. A relatively recent implementation of optical coherence tomography, frequency-domain optical coherence tomography, provides advantages in signal-to-noise ratio, permitting faster signal acquisition. Commercially available optical coherence tomography systems are employed in diverse applications, including art conservation and diagnostic medicine, notably in ophthalmology where it can be used to obtain detailed images from within the retina. Recently it has also begun to be used in interventional cardiology to help diagnose coronary artery disease. [Wikipedia]

OCT image of a finger tip recorded using a SuperK supercontinuum laser.
Image courtesy of Professor Ruikang Wang