Laplace Field Microscopy (LFM)/Gradient Field Microscopy (GFM)

Posted on February 29, 2012 by Taewoo

Laplace Field Microscopy (LFM) is developed as a outside module to a commercial bright field microscope. It gives an differential phase image using a 4f system and a spatial light modulator (SLM) to introduce an intensity modulation at the spatial frequency domain. By giving the parabolic intensity modulation at the k-space, the system extracts the Laplacian of the scattered field at the detector.

This intensity of the Laplacian of the scattered field is represented as the sum of the square of the second order derivative of the phase and the 4th-power of the first order derivative of the phase. Compared to the differential interference contrast (DIC) microscopy, LFM shows its advantage by getting rid of the directional artifact. Since the dynamics of many different object is described by the Laplacian of the field, with its fast-measurement ability, LFM shows its potential to be used in a dynamics study of biological objects.

Gradient field microscopy (GFM) shares the same setup as LFM, but it provides the first order derivative of the field using different filters.

 

LFM related publications.
  1. T. Kim  and G.Popescu,  Laplace field microscopy for label-free imaging of dynamic biological structures, Opt. Lett., 36 (23), 2011
  2. T. Kim, S. Sridharan and G. Popescu, Gradient field microscopy of unstained specimens, Opt. Exp., 20 (6), 6737 (2012).
  3. T. Kim, S. Sridharan, and G. Popescu, Gradient field microscopy allows label-free disease diagnosis (invited), Laser Focus World, 48 (8), (2012)
  4. T. Kim, S. Sridharan, A. Kajdacsy-Balla, K. Tangella, and G. Popescu, Gradient field microscopy for label-free diagnosis of human biopsies, Appl. Opt. (Special Issue on Holography), 52 (1), A92-A96 (2013)