Biophotonics Laboratory
California Institute of Technology


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Xiquan Cui

Xiquan Cui

Research Scientist at the Biological Imaging Center (BIC) studying Age-related Macular Degeneration (AMD)


PhD Electrical Engineering, California Institute of Technology, 2009
BS & MS, Optical engineering, Zhejiang University, China, 2003
MS, Physics, Portland State University, USA, 2005

Research Overview

While working in the Biophotonics group, my research was primarily focused on studying how light behaves and interacts with nano systems, and inventing novel micro/nano fluidic devices with optical components to further the diagnostic and measurement techniques in biomedicine.

Biophotonics projects

Compact optofluidic microscope (OFM)
The OFM is an imaging system developed by our group. It uses a line of nanoapertures on a metal film as a multiple near-field probe array to collect the near-field optical information of the cells or micro-organisms flowing in the microfluidic channel. Because of its near-field detection feature, the OFM has no bulky lens and can achieve a resolution higher than the diffraction limit. I helped to develop a new OFM fabrication method which will make it compatible with current micro-fabrication techniques. The goal is to integrate the OFM onto microfluidic chips and make the smallest "camera" in the world.

Nanofluidic Fluorescent Display (NFD)
Based on Daniel Kleppner's "Inhibited Spontaneous Emission" paper in 1981, we proposed a new type of fluorescent flat panel display technique, which has the following advantages: no limit on screen size, fast response, energy economy and low cost. This display technique is based on controlling the fluorescent emission of charged fluorophores in nano metal fluidic channels by a bias voltage. I developed nano metal fluidic channels which can suppress fluorescent emission in any designed wavelength, and studied the migrating dynamics of charged fluorophores in nano metal fluidic by electrophoresis. But this is not just a simple new display technique. It is a cool technique with which one can control the so-called "spontaneous" emission by tuning its environmental vacuum.