Spatial light interference tomography (SLIT)

Zhuo Wang,Supriya G Prasanth,Daniel L Marks,Larry J Millet,Martha U Gillette,Zhen Shen,Paul V Braun,Gabriel Popescu,Paul Scott Carney,Agustin Mihi

doi:10.1364/oe.19.019907

Abstract

We present spatial light interference tomography (SLIT), a label-free method for 3D imaging of transparent structures such as live cells. SLIT uses the principle of interferometric imaging with broadband fields and combines the optical gating due to the micron-scale coherence length with that of the high numerical aperture objective lens. Measuring the phase shift map associated with the object as it is translated through focus provides full information about the 3D distribution associated with the refractive index. Using a reconstruction algorithm based on the Born approximation, we show that the sample structure may be recovered via a 3D, complex field deconvolution. We illustrate the method with reconstructed tomographic refractive index distributions of microspheres, photonic crystals, and unstained living cells.

Highlights

Received 7 Jun 2011; revised 14 Sep 2011; accepted 16 Sep 2011; published 27 Sep 2011 10 October 2011 / Vol 19, No 21 / OPTICS EXPRESS 19908 rendered serially, i.e., point by point, and the out-of-focus light is rejected by a pinhole in front of the detector
We record a quantitative phase image using the principle of spatial light interference microscopy (SLIM), described in more detail elsewhere [29]
The optical gating due to the lowcoherence of light is at the heart of optical coherence tomography, which is a wellestablished method for deep tissue imaging [37]

Summary

Introduction

Received 7 Jun 2011; revised 14 Sep 2011; accepted 16 Sep 2011; published 27 Sep 2011 10 October 2011 / Vol 19, No 21 / OPTICS EXPRESS 19908 rendered serially, i.e., point by point, and the out-of-focus light is rejected by a pinhole in front of the detector. Label-free methods are preferable especially when photobleaching and phototoxicity play a limiting role It has been known since the work by von Laue and the Braggs that the structure of 3D, weakly scattering media, can be determined by far-zone measurements of scattered electromagnetic fields [3]. The scattered fields are uniquely related to the structure of the object, but a given intensity may be produced by many fields, each corresponding to a different sample structure. This nonuniqueness inherent in intensity measurements may be overcome by prior assumptions and within certain approximations, e.g. see Ref [6]

Objectives

Results

Conclusion