Biophotonics, the science of utilizing photons to image or manipulate biological samples, allows direct visualization and interaction at the cellular and sub-cellular level. The broad field of biophotonics includes numerous technologies, such as: multiphoton imaging, confocal microscopy and optical coherence tomography, each offering different advantages. AdvancedMEMS enabling technology provides high-speed, high-resolution beam steering in a mm scale, low power package, allowing the miniaturization and productization of biophotonic systems.

A primary focus area of AdvancedMEMS is in the area of clinical and endoscopic optical coherence tomography imaging.

Optical coherence tomography (OCT) is an emerging imaging modality capable of achieving high resolution, cross-sectional images in tissue and other materials. Due to the non-destructive nature of low-power optical imaging technologies, biophotonics has become a major area of research focus in both academia and industry. In particular OCT has received a great deal of attention in the fields of biology and medicine. This is due, in part, to the fact that in addition to providing high resolution, non-destructive tomographic imaging capabilities OCT provides the opportunity to simultaneously realize real-time visualization of tissue structure and blood flow in a non-invasive, or minimally invasive, manner.

Currently, imaging technologies such as ultrasound and Doppler ultrasound are employed to obtain minimally invasive, in-vivo, real-time images of tissue structure and blood flow profiles. However, the spatial resolution of these techniques is limited to approximately 100μm due to the relatively long wavelength of acoustics waves. OCT takes advantage of the short coherence length of broadband light sources in order to achieve cross-sectional images with micrometer (2-10μm) scale resolution. Due to the limited penetration depth of OCT systems in most biological tissue (approximately 2-3mm) miniaturized endoscopic probes are required for imaging of internal organs and tissue. Furthermore, small handheld probes with fast imaging speeds, excellent stability and ease of use are required for a wide range of clinical applications including ophthalmology and imaging of the skin as well as the oral cavity. Advances in silicon micromachining and micro-electromechanical systems (MEMS) technologies provide an enabling technology, allowing a new approach to be taken in order to achieve high-speed, high resolution OCT imaging. Modern photolithography and micromachining technologies allow the realization of structures and devices that are capable of manipulating light with sub-wavelength precision. The small physical size of MEMS optical components is highly advantageous when building miniaturized, portable scanning heads, hand-held scanners and minimally invasive endoscopic probes. In addition, MEMS technologies allow the realization of miniature optical systems exhibiting both high speed and low power operation.

AdvancedMEMS and our collaborators demonstrated the first three-dimensional (3-D), high-resolution, video rate capable, MEMS based OCT system. High speed, 3-D OCT provides several improvements and advantages compared to 2-D imaging. The ability to arbitrarily visualize and manipulate 3-D images of tissue containing lesions and tumors provides significant additional diagnostic information to both physicians and researchers.


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