Third-Order Nonlinear Spectrum of GaN under Femtosecond-Pulse Excitation from the Visible to the Near Infrared

Autor(es)

Almeida, Gustavo E. B. ^{[1, 2]} ; Santos, Sabrina N. C. ^[2] ; Siqueira, Jonathas P. ^[2] ; Dipold, Jessica ^[2] ; Voss, Tobias ^{[3, 4]} ; Mendonca, Cleber R. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Uberlandia, Inst Phys, POB 593, BR-38400902 Uberlandia, MG - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Phys, POB 369, BR-13561970 Sao Carlos, SP - Brazil

^[3] Tech Univ Carolo Wilhelmina Braunschweig, Inst Semicond Technol, D-38106 Braunschweig - Germany

^[4] Tech Univ Carolo Wilhelmina Braunschweig, Lab Emerging Nanometrol LENA, D-38106 Braunschweig - Germany

• Tipo de documento: Artigo Científico
• Fonte: PHOTONICS; v. 6, n. 2 JUN 2019.
• Citações Web of Science: 0

Resumo

Gallium nitride (GaN) has been established as a promising candidate for integrated electro-optic and photonic devices, aiming at applications from optical switching to signal processing. Studies of its optical nonlinearities, however, lack spectral coverage, especially in the telecommunications range. In this study, we measured the two-photon absorption coefficient (beta) and the nonlinear index of refraction (n(2)) of GaN from the visible to the near-infrared by using femtosecond laser pulses. We observed an increase of beta from (1.0 +/- 0.2) to (2.9 +/- 0.6) x10(-11) m/W as the photon energy approached the band gap from 1.77 up to 2.25 eV (700-550 nm), while n(2) varied from (90 +/- 30) x10(-20) up to (265 +/- 80) x10(-20) m(2)/W within a broad spectral range, from 0.80 up to 2.25 eV (1550-550 nm). The results were modeled by applying a theory based on the second-order perturbation theory and the Kramers-Kronig relationship for direct-gap semiconductors, which are important for the development of GaN-based nonlinear photonic devices. (AU)

• Processo FAPESP: 18/11283-7 - Fotônica não linear: espectroscopia e processamento avançado de materiais
• Beneficiário: Cleber Renato Mendonça
• Modalidade de apoio: Auxílio à Pesquisa - Temático