Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Accessing nonlinear phase contrast in biological tissue using femtosecond laser pulse shaping

Not Accessible

Your library or personal account may give you access


Nonlinear imaging takes advantage of the localized nature of the interaction to achieve high spatial resolution, optical sectioning, and deeper penetration in tissue. However, nonlinear contrast (other than fluorescence or harmonic generation) is generally difficult to measure because it is overwhelmed by the large background of detected illumination light. Especially challenging to measure is the nonlinear refractive index – accessing this quantity would allow the extension of widely employed phase microscopy methods to the nonlinear regime. We have developed a technique to suppress the background in these types of measurements by using femtosecond pulse shaping to encode nonlinear interactions in background-free regions of the frequency spectrum. Using this individual pulse shaping based technique we have been able to measure self-phase modulation (SPM) in highly scattering environments, such as biological tissue, with very modest power levels. Using our measurement technique we have demonstrated strong intrinsic SPM signatures of glutamate-induced neuronal activity in hippocampal brain slices. We have also extended this measurement method to cross-phase modulation, the two-color analogue to SPM. The two-color approach dramatically improves the measurement sensitivity by reducing undesired background and associated noise. We will describe the nonlinear phase contrast measurement technique and report on its application for imaging neuronal activity.

© 2011 OSA/SPIE

PDF Article
More Like This
Nonlinear phase contrast imaging in neuronal tissue

Prathyush Samineni, Martin C. Fischer, Henry C. Liu, Ryohei Yasuda, and Warren S. Warren
NMD3 Novel Techniques in Microscopy (NTM) 2011

Intrinsic Nonlinear Optical Signatures of Neuronal Activity

Henry C. Liu, Martin C. Fischer, Prathyush Samineni, Yasmin Escobedo-Lozoya, Ryohei Yasuda, and Warren S. Warren
FWD2 Frontiers in Optics (FiO) 2008

Cross-phase Modulation Microscopy

Prathyush Samineni, Martin C. Fischer, and Warren S. Warren
LTuA2 Laser Science (LS) 2011


You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
Login to access Optica Member Subscription

Select as filters

Select Topics Cancel
© Copyright 2023 | Optica Publishing Group. All Rights Reserved