Current Institution: Agile Focus Designs
Agile focusing in active optical systems
Imaging systems have traditionally relied upon translation of lenses for focus control. However, this proves slow and difficult to miniaturize for small form factor imaging systems such as endoscopes and cell phone cameras . Microelectromechanical systems (MEMS) mirrors present an electronic means for fast focus control, while maintaining a small form factor. In this presentation I will describe novel, low-actuator-count MEMS mirrors for fast focus control with concurrent management of attendant spherical aberration in a transmission microscope , a disk read head , and a confocal microscope . In a recent work, I synchronized the MEMS mirror with the fast scan axis to obtain oblique plane images of Drosophila larvae, which is much faster than acquiring an x-y-z stack for later processing . Additionally, I showed improvement of point-spread-functions over 120 mm focal range at 0.55 NA with active focusing and correction of spherical aberration. SPIE selected the work as having great potential to impact health care.
The capability of these mirrors for agile focus control over a 3D surface could significantly improve imaging of time-sensitive biological phenomenon, optical biopsy during medical procedures, 3D printing or scanning of small objects, and image feature tracking or stabilization. Their performance has also been improved by a capacitive sensing/control scheme that has increased the usable stroke range (inversely proportional to focal length) of these devices by more than 50 % . Applied Optics has accepted a paper that explores the range of lower order and higher order spherical aberration correction these MEMS mirrors can demonstrate while focusing, as well as a training scheme and demonstration for use in scanning systems . I will also discuss an aberration analysis that is based on the characteristic function of the optical system that outlines the inherent capabilities and limitations of deformable mirrors. This analysis should be beneficial for new designs of optical instruments that incorporate active focusing mirrors, leveraging their precision, speed, and small size to build more functional and useful instruments for biomedicine and industrial imaging applications. The presentation will include recent efforts under an NSF Phase I SBIR (150k) grant to commercialize 3D imaging technology with novel MEMS mirrors.  Dickensheets et al., Intl. Conf. Micro/Nano Optical Engineering (2011).  Lukes et al., JMEMS, 22, 94-106 (2013).  Lukes et al., SPIE MOEMS, 82520L (2012).  Lukes et al., “SPIE BiOS, 89490W (2014). (Selected as translational) Lukes et al., JM3, 8, 043040 (2009).  Lukes et al., ” Four-zone varifocus mirrors with adaptive control of primary and higher-order spherical aberration,” accepted by J. of Applied Optics.
 Dickensheets et al., Intl. Conf. Micro/Nano Optical Engineering (2011).
 Lukes et al., JMEMS, 22, 94-106 (2013).
 Lukes et al., SPIE MOEMS, 82520L (2012).
 Lukes et al., “SPIE BiOS, 89490W (2014). (Selected as translational)
 Lukes et al., JM3, 8, 043040 (2009).
 Lukes et al., ” Four-zone varifocus mirrors with adaptive control of primary and higher-order spherical aberration,” accepted by J. of Applied Optics.
Sarah J. Lukes enjoys working in an interdisciplinary field where electrical, optical, and mechanical systems benefit biomedical engineering applications. As an undergraduate intern, she developed a computer program and interface for technicians to help diagnose osteoarthritis from radiographs at the Mayo Clinic in Rochester, MN. The accuracy proved better than a radiologist’s measurements of minimum joint space widths, where the results are published. She also worked on 3D test and imaging methods for stents designed for the superficial femoral artery as an R&D intern at Boston Scientific in Minneapolis, MN. After attaining an undergraduate degree in mechanical engineering, she designed vibration reduction systems at cryogenic temperatures for LIDAR applications at S2 Corporation, a start-up company.
She then earned her Ph.D. in engineering with an emphasis in electrical engineering in May of 2015 at Montana State University with support of an NSF Graduate Research Fellowship. During her studies, Dr. Lukes gained expertise in optical MEMS while publishing 14 papers, 10 of which she is first author. She was honored by the university with the Betty Coffey Award for her promotion of women in the College of Engineering, and she was among 12 U.S. students selected by National Nanofabrication Infrastructure to attend its International Winter School in Bangalore, India to gain further nanofabrication expertise and learn about novel technologies that are impacting rural areas.
After graduating with her PhD, Dr. Lukes applied as principle investigator for and was awarded an NSF Phase I SBIR (150k for 6 months) and Montana Stage 1 funding (30k) for her newly founded company, Agile Focus Designs. Her team is working toward commercialization of novel 3D imaging technology. SPIE International Society of Photonics and Optics also invited her to write an upcoming SPIE Spotlight Author eBook entitled, “Dynamic and Agile Focusing in Microscopy: A Review.” Below is a list of selected publications that are not included in the attached research statement.