Independent Activities Period (IAP) January 2005

Optical Imaging, Scattering, and Interference for Biological Investigations

Dr. Gabriel Popescu

January 5 - 20
2 PM - 3 PM, MIT Room 1-375

The theme of this course is the study of modern optical technologies based on microscopy, scattering, and interference for biomedical investigations. Optical fields will be described in the framework of linear system theory, and the use of Fourier transforms will be introduced as a powerful tool for describing their temporal and spatial fluctuations. This approach will provide common ground for formulating the various optic methodologies presented. A basic description of imaging systems will be developed with resolution, and contrast as key properties. Coherent imaging and various ways of improving contrast will be addressed. Various methods of microscopy will be considered, including bright field, dark field, Schlerein, confocal, OCT, phase contrast, DIC, Nomarsky, and quantitative phase imaging. Various models of scattering of light by inhomogeneous media will be formulated, and light scattering spectroscopy will be presented as a tool for early cancer diagnosis and other applications. The principles of interferometry will be presented, and particular geometries will be discussed. Both amplitude and phase-based techniques will be introduced. To provide focus, each student will be expected to write a paper on a particular optical methodology.

The course will build from the basic principles of optics, and thus will be accessible to a broad audience with interest in biomedical optics, but prior acquaintance with optics and EM theory will definitely help. Those interested should contact Gabriel Popescu (gpopescu@mit.edu).

1. January 5, Wednesday
Introduction

2. January 6, Thursday
Math toolbox: linear systems, convolutions, Fourier transforms, useful theorems

3. January 7, Friday
Elements of optical microscopy: imaging systems, resolution, contrast, examples

4. January 10, Monday
Bright field, dark field, Schlerein, phase contrast, DIC/ Nomarski, confocal, etc

5. January 11, Tuesday
Light scattering techniques: light scattering in inhomogeneous media, single scattering, multiple scattering, diffusion model

6. January 12, Wednesday
Light scattering spectroscopy and diagnostics of early cancer

7. January 13, Thursday
Interferometric methods for diagnostics: field cross- correlations, cross-spectral densities; coherence time, area, interferometric geometries

8. January 14, Friday
Michelson interferometry with polychromatic fields: optical gating, ODR- optical domain reflectometry, thickness/ refractive index measurements, OCT and applications

9. January 18, Tuesday
Phase-based techniques of investigation: point measurements, harmonic, phase-referenced

10. January 20, Thursday
Quantitative phase microscopy: Fourier Phase Microscopy, applications for imaging cellular structure and dynamics

Sponsored by the G.R. Harrison Spectroscopy Laboratory