SCIEN Talk

A fundamental challenge of healthcare is to meet the increasing demand for quality of care while minimizing the cost. We aim to make meaningful contributions to solve the challenge by creating innovative, minimally-invasive imaging and image-guided robotics technologies collaborating with leading research hospitals and other stake holders. In this lecture, we present technologies under development such as ultra-miniature endoscope, image-guided needle robot, and scanning-laser ophthalmoscope, and discuss how we can potentially address unmet clinical needs.

The recent availability of miniaturized photon counting pixels in standard CMOS processes has paved the way to the introduction of photon counting in low-cost image sensors. The uses of these devices are multifold, ranging from LIDARs to Raman spectroscopy, from fluorescence lifetime to molecular imaging, from super-resolution microscopy to data security and encryption.

In this talk we describe the technology at the core of this revolution: single-photon avalanche diodes (SPADs) and the architectures enabling SPAD based image sensors. We discuss tradeoffs and design trends, often referring to specific sensor chips, new materials for extended sensitivity, and 3D integration for ultra-high speed operation. We also discuss the recent impact of SPAD cameras in metrology, robotics, mobile phones, and consumer electronics.

Colour science has been widely used in the imaging industry. This talk will introduce some new development areas of colour science. Among them, three areas related to imaging technology will be focused upon: LED lighting quality, CIE 2006 colorimetry, comprehensive colour appearance modelling. LED lightings has recently making great advances in the illumination industry. It has a unique feature on adjustability, capable of tuning its spectral for different applications. A tuneable LED system for image sensor applications such as white balance, calibration and characterisation will be introduced. It will be demonstrated and its performance will be reported.

Whereas in the beginning of visual computing, mostly rudimentary physical models or rough approximations were employed to allow for real-time simulations, several modern applications of visual computing and related disciplines require fast and highly accurate numerical simulations at once; for example interactive computer-aided design and manufacturing processes, digital modeling and fabrication, training simulators, and intelligent robotic devices. This talk covers a selection of high fidelity algorithms and techniques for the fast simulation of complex scenarios; among others symbolic-numeric coupling, structure preserving integration, and timescale segmentation. Their powerful behavior is presented on a broad spectrum of concrete applications in science and industry from the simulation of biological microswimmers and molecular structures to the optimization of consumer goods like toothbrushes and shavers.

Cancer. Infertility. Hearing loss. Each of these phrases can bring a ray of darkness into an otherwise happy life. The Stanford Biomedical Optics group, led by Professor Audrey Bowden, aims to develop and deploy novel optical technologies to solve interdisciplinary challenges in the clinical and basic sciences. In short, we use light to image life -- and in so doing, illuminate new paths to better disease diagnosis, management and treatment. In this talk, I will discuss our recent efforts to design, fabricate and/or construct new hardware, software and systems-level biomedical optics tools to attack problems in skin cancer, bladder cancer, hearing loss and infertility. Our efforts span development of new fabrication techniques for 3D tissue-mimicking phantoms, new strategies for creating large mosaics and 3D models of biomedical data, machine-learning classifiers for automated detection of disease, novel system advances for multiplexed optical coherence tomography and low-cost technologies for point-of-care diagnostics.

SCIEN Talk: 

Conventional optical components rely on the propagation through thick materials to control the amplitude, phase and polarization of light. Metasurfaces provide a new path for designing planar optical devices with new functionalities. In this approach, the control of the wavefront is achieved by tailoring the geometry of subwavelength-spaced nano antennas. By designing an array of low-loss dielectric resonators we create metasurfaces with an engineered wavelength-dependent phase shift that compensates for the dispersion of the phase accumulated by light during propagation. In this way the large chromatic effects typical of all flat optical components can be corrected. A flat lens without chromatic aberrations and a beam deflector are demonstrated. The suppression of chromatic aberrations in metasurface-based planar photonics will find applications in lightweight collimators for displays, and chromatically-corrected imaging systems.