Adaptive Optics and Biophotonics group
In the News
March 6, 2007
Holographic images use shimmer to show cellular response to anticancer drug
The response of tumors to anticancer drugs has been observed in real-time 3-D images using technology developed at Purdue University.
October 17, 2005
David D. Nolte was the winner of the 2005 Herbert Newby McCoy Award
The Herbert Newby McCoy Award is Purdue University's highest award for outstanding contributions to science.
| McCoy Distinguished Lecture (PDF)
May 18, 2004
BioCDs could hit No. 1 on doctors' charts
While-you-wait medical tests that screen patients for thousands of disease markers could be possible with compact-disk technology patented by Purdue University scientists.
July 17, 2004
Emerging Technology: Diagnostic Tests on CD-ROM
The future of diagnostic blood tests may lie in your computer's CD drive -- if a Purdue scientist can carry out his vision.
May 7, 2002
Lasers light way to 3-D imaging in Purdue lab
Purdue University scientists developing a new imaging technology have created the world's first "visual fly-throughs" of a living tumor.
Quadraspec™
Prof. Nolte is a technical founder of Quadraspec, Inc., located at the Purdue Research Park, that is commercializing the BioCD with products for diagnostic testing using label-free highly sensitive assays with high content.
The adaptive optics and biophotonics group, directed by Professor Nolte, studies a broad spectrum of problems that range from Bio-CDs (Biological Compact Disks) that rely on microdiffraction of lasers from pits containing antibodies, to real-time video flythroughs of rat bone-cancer tumors using adaptive holography. What the projects share in common is the use of lasers and coherent optics to study biological systems. Some of the approaches use the most sensitive dynamic holographic films developed to date. These films are made from optoelectronic semiconductor materials similar to the lasers in CD players. By bringing self-adaptive optics to bear on antibodies binding pathogens, we are attempting to measure small concentrations of toxin molecules, down to the level of one molecule per track per spot on the Bio-CD.
The BioCD
The BioCD The BioCD performs molecular diagnostics in the form of a compact disc. The BioCD, invented in the Adaptive Optics and Biophotonics group at Purdue University, combines the simplicity of spinning-disc interferometry (SDI) with the power of antibodies to detect disease. A conventional compact disc has 5 billion diffraction-limited pits encoding digital information. The motivation behind the BioCD is to turn a disc into 5 billion micro-test-tubes to test for every type of blood protein in a few drops of blood. The science of molecular interferometry combines the physics of laser coherence, quantum optics, light-matter interactions, and surface science, with molecular biology and biomedical diagnostics. | Tutorial on Molecular Interferometry |
Holographic Optical Coherence Imaging
Laser fields propagating through scattering tissue retain an exponentially decaying coherence that can write holographic gratings on a holographic medium. The first volumetric holograms of living tissue were made by the Adaptive Optics and Biophotonics group at Purdue University in 2002 using ultra-sensitive dynamic holographic film called photorefractive quantum well (PRQW) devices. Digital holography, using CCD cameras, provides similar advantages for holographic optical coherence imaging (OCI). In biomedical imaging applications, cellular motion, recorded as shimmering holograms, acts as a novel imaging contrast agent. Recent interest is on the action of anti-mitotic cancer drugs on tissue. | Cellular motility as a novel contrast agent in digital holography of tissue
Microfluidics
Following the example of integrated electronic circuits, the "lab-on-a-chip" uses micro-fabrication to create microfluidic systems that transport liquid samples through reaction and analysis chambers for biochemical assays. We are studying the fundamental physics of fluids in micron and nanometer-scale systems. The unstable fingering of invading phases in 2D random systems, and thermodynamic properties of liquids in contact with other liquids or solids, leads to strong hysteretic relationships between saturation and capillary pressure that has eluded clear theoretical explanation. Moving into three dimensions is being pursued by building porous microsystems using two-photon polymerization (2PP) laser micromachining.
Nonlinear Optics
The Adaptive Optics and Biophotonics group at Purdue has developed the world's most sensitive dynamic holographic film, semiconductor devices called Photorefractive Quantum Wells (PRQW). The nonlinear optical properties of the PRQW devices lead to the largest index change per photon of any optical nonlinearity. The physics behind the PRQW involves nonlinear electronic transport, electro-optics, quantum-confined excitons, deep-level defects, space-charge fields, and coherent mixing of laser fields. Applications of PRQW devices includes adaptive interferometry, laser-based ultrasound detection, fsec dispersion compensation, and holographic optical coherence imaging.
