Feature Of The Week 9/22/13: Lehigh University Researchers Investigate Space-Division Multiplexing for High-Speed Optical Coherence Tomography
High speed, high resolution and high sensitivity are desirable for optical coherence tomography (OCT). Here, we demonstrate a space-division multiplexing (SDM) technology that translates long coherence length of a commercially available wavelength tunable laser into high OCT imaging speed. We achieved an effective 800,000 A-scans/s imaging speed using a commercially available 100,000 Hz tunable vertical cavity surface-emitting laser (VCSEL) from Thorlabs Inc. A sensitivity of 94.6 dB and a roll-off of < 2 dB over ~30 mm imaging depth were measured in the prototype SDM-OCT system. An axial resolution of ~11 um in air (or ~8.3 um in tissue) was achieved throughout the entire depth range. An in vivo, 3D SDM-OCT volume of an entire Drosophila larva consisting of 400 x 605 A-scans was acquired in 0.37 seconds. Synchronized cross-sectional OCT imaging of three different segments of a beating Drosophila larva heart is demonstrated. The SDM technology provides a new orthogonal dimension for further speed improvement for OCT with favorable cost scaling. It can be used in combination with ultrahigh speed tunable lasers with long coherence length, such as VCSEL and FDML lasers, to achieve further speed improvement. Further improvement in data acquisition and transfer rate, bandwidth of the detectors, coherence length of the light source, and number of fiber channels will further scale up OCT axial scan rate linearly with minimum additional cost. SDM-OCT also preserves image resolution and allows synchronized cross-sectional and three-dimensional (3D) imaging of biological samples, enabling new biomedical applications.
For more information see recent Article. Courtesy of Chao Zhou from Lehigh University.