Author: Christopher M Martin
Requested Type: Poster
Submitted: 2015-05-04 14:36:19
Co-authors: A. Ben-Yakar
The University of Texas at Austin
4601 Avenue D
Austin, Texas 78751
Current femtosecond laser surgery techniques are limited in their ability to penetrate deeply into tissue without causing collateral damage. The high powers required for ablation can cause laser beam self-focusing, leading to extended axial damage or requiring the use of high numerical-aperture, low working-distance objectives. Further, high powers can cause ablation at the surface of the tissue. Multiple scattering through turbid media generates speckle patterns and spatial distortions of the beam profile, leading to ablation outside the intended focus.
Simultaneous spatial and temporal focusing (SSTF) allows wide-field, axially confined ablation while potentially eliminating the deleterious effects of self-focusing, surface damage, and speckle damage. In SSTF, the laser beam is spectrally dispersed into low numerical aperture beamlets before an objective lens, only to recombine and give a transform limited pulse width at the focal plane. Thus, multiphoton effects are restricted to the focal plane.
We demonstrate the application of SSTF for deep tissue surgery. Subsurface ablation voids are created in tissue samples with low numerical-aperture and high working-distance objectives without collateral damage. Additionally, the voids are repeatable, indicating that SSTF is robust to scattering and speckle patterns. We compare SSTF ablation to standard ablation methods and discuss benefits for each technique.
Category: Nonlinear optics and laser surgery. Requesting Tuesday evening poster session.