Ultrafast optical image processing based on third-harmonic generation in organic thin films

Abstract

We report on the use of the noncollinear third-harmonic generation in an amorphous polymer film operating in the eye safe and telecommunication compatible near-infrared range to perform ultrafast all-optical two-dimensional (2D) image processing at 1550nm using 100fs pulses. The background-free and nondegenerate outputs at 517nm are easily spatially filtered and detected with low cost electronic components. We describe this Fourier transform based technique and demonstrate its application to the classical problem of 2D image recognition.

Ultrafast Third-Order Nonlinear Optical Response Excited by fs Laser Pulses at 1550 nm in GaN Crystals

“…To the best of our knowledge, the ultrafast third-order nonlinear response in GaN, excited by femtosecond (fs) laser pulses, has not been measured directly by third-harmonic generation (THG), in particular in the telecommunication spectral range. The THG method allows the direct measurement of the fastest third-order nonlinear optical response of solely electronic origin [31][32][33][34]. At the wavelength of λ = 1550 nm the photon energy is E ph = 0.8 eV, which is more than four times lower than the GaN bandgap (E ph < E g /4).…”

Third-harmonic generation and its applications in optical image processing

“…When implemented with ultrafast nonlinear optical (NLO) processes, computational rates exceeding 10 16 operations/second could be achieved 5 in relatively inexpensive and very compact optical correlators. 4,9,10 In comparison, occupying an area of around 560 m 2 , IBM Roadrunner, the fastest supercomputer today, can perform 1.7 Â 10 15 floating point operations per second. 11 Among the wide variety of c (3) processes that can be used to implement AOSP, third-harmonic generation (THG) is attractive because it is an inherently ultrafast electronic process.…”

“…Section 3 presents the linear and NLO properties of the polymer composite we used previously to demonstrate several applications. 9,10,16,17,21 Section 4 describes in detail the use of time-gated noncollinear THG to demonstrate ballistic-photon imaging through scattering media. Section 5 describes the implementation of a compact THG-based optical image correlator and its applications to the problem of image recognition.…”