UNIVERSITY OF PITTSBURGH THE

This award provides funding to acquire a high-power, high-repetition-rate, wavelength-tunable, femtosecond ultrafast laser system to study laser material interaction and to fabricate three-dimensional photonic devices. The ultrafast laser processing defines the forefront of today's laser processing technology. Femtosecond laser pulses drive universal multi-photon photosensitivity process to change refractive index in many transparent materials. By tightly focusing the laser beam into optical substrates, the multi-photon process produces below diffraction-limit nanometer-size refractive index change for the ultra-high precision optical device fabrication. Laser-induced material damage can be mitigated by exploiting the bulk heating effect from high-repetition laser pulses. Using the acquired laser system, the mechanism of ultrafast laser photosensitivity will be thorough studied. The optimal laser processing window for a wide array of optical materials will be explored to fabricate high performance three-dimensional photonic devices that are un-attainable by other fabrication approach. The success of the proposed research will yield a cross-platform laser fabrication technique to produce high-quality and low-loss lightwave circuits in a wide array of optical substrates for both active and passive applications. It will drastically increase the density, functionality, and complexity of the optical circuitry. This program also enables unique multi-disciplinary training opportunities for both graduate and undergraduate students. Training opportunities will cover all aspects of the laser fabrication technology including lasers, optical designs, computer control, machine vision, microstructure analysis, fiber optics, and nonlinear optics. Recruited through the University of Pittsburgh's minority mentor EXCEL program, underrepresented minority and female students to will be encouraged to participate in academic research and training.

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