Two-Photon Optical Beam-Induced Current Microscopy of Light-Emitting Diodes

  • Godofredo Bautista Jr.
  • Carlo Mar Blanca
  • Caesar Saloma

Abstract

We demonstrate two-photon optical beam-induced current (2P-OBIC) microscopy of light-emitting diodes (LEDs). We utilized a Ti:Sapphire femtosecond laser source operating at 800 nm to derive the 2P-OBIC signal from a 605 nm band-gap LED. The spatial confinement of free carrier generation only at the focus and the quadratic dependence of the 2P-OBIC signal on excitation power are the key principles in two-photon excitation. As a consequence, superior image quality evident in the 2P-OBIC images of LEDs are obtained. These features decrease the linear absorption and wide-angle scattering effects plaguing single-photon optical beam-induced current (1P-OBIC) technique, thereby increasing the resolution of the imaging system in the axial and lateral directions. Thus, the attainment of good axial discrimination in the LED samples is obtained even without a confocal pinhole. In addition, 2P-OBIC images reveal local variations in free carrier densities which are not evident in the single-photon excitation.
Published
2007-07-13
How to Cite
BAUTISTA JR., Godofredo; BLANCA, Carlo Mar; SALOMA, Caesar. Two-Photon Optical Beam-Induced Current Microscopy of Light-Emitting Diodes. Science Diliman: A Journal of Pure and Applied Sciences, [S.l.], v. 16, n. 2, july 2007. ISSN 2012-0818. Available at: <https://journals.upd.edu.ph/index.php/sciencediliman/article/view/108>. Date accessed: 02 sep. 2025.
Section
Articles

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