This paper reports preliminary results from the development and application of a two-dimensional MEMS endoscopic scanner for OCT imaging. A 1 mm diameter mirror provides high aperture over large scan angle and can scan at rates of hundreds of Hz in both axes. The mirror is integrated with focusing optics and a fiber-optic collimator into a package of ~5 mm diameter. Using a broadband femtosecond laser light source, ultrahigh axial image resolution of < 5 um in tissue is achieved at 1.06 um center wavelength. Ultrahigh resolution cross-sectional and three-dimensional OCT imaging is demonstrated with the endoscope with ~12 um transverse resolution and < 5 um axial resolution.
An overview of the current state of the art in scanning micromirror technology for switching, imaging, and beam steering applications is presented. The requirements that drive the design and fabrication technology are covered. Electrostatic, electromagnetic, and magnetic actuation techniques are discussed as well as the motivation toward combdrive configurations from parallel plate configurations for large diameter (mm range) scanners. Suitability of surface micromachining, bulk micromachining, and silicon on insulator (SOI) micromachining technology is presented in the context of the length scale and performance for given scanner applications.
A grism typically consists of a transmission grating attached to a prism and constitutes an important optical element for spectroscopic astronomical observations. Here, we present a new type of grism that includes a volume phase holographic grating and evaluate its performance in detail using the rigorous coupled wave analysis (RCWA). Based on the knowledge gained from this evaluation we were able to design and fabricate a grism prototype with good performance.
High quality imaging technologies have been developed for color inkjet printers with a piezoelectric print head. In these technologies, we have used the MLChips head to eject multi-sized micro droplets in the most suitable placements and added a lower density ink in the cyan and magenta color components for the reproduction of highlighted areas. In addition to this hardware technology, we have developed halftone algorithms to obtain smoother tone reproduction. These technologies greatly decrease noise on the output and achieves very high quality image.
Conference Committee Involvement (2)
Color Imaging IX: Processing, Hardcopy, and Applications IX
20 January 2004 | San Jose, California, United States
Color Imaging VIII: Processing, Hardcopy, and Applications