Characterizations of nonlinear optical properties on GaN crystals in polar, nonpolar, and semipolar orientations

Abstract

We report the basic nonlinear optical properties, namely, two-photon absorption coefficient (b), three-photon absorption coefficient (c), and Kerr nonlinear refractive index (n kerr), of GaN crystals in polar c-plane, nonpolar m-plane, and semipolar (2021) plane orientations. A typical Z-scan technique was used for the measurement with a femtosecond Ti:S laser from wavelengths of 724 nm to 840 nm. For the two-photon absorption coefficient (b), similar values were obtained for polar, nonpolar, and semipolar samples, which are characterized to be $0.90 cm/GW at 724 nm and $0.65 cm/GW at 730 nm for all the three samples. For the Kerr nonlinear refractive index (n kerr), self-focusing features were observed in this work, which is different from previous reports where self-defocusing features were observed on GaN in the visible and near-UV spectral regions. At 724 nm, n kerr was measured to be $2.5 0 Â 10 À14 cm 2 =W for all three samples. Three-photon absorption coefficients (c) were also determined, which were found to be consistent with previous reports. This study provides valuable information on the basic nonlinear optical properties of III-nitride semiconductors, which are vital for a wide range of applications such as integrated photonics and quantum photonics.

Four-wave mixing and nonlinear parameter measurement in a gallium-nitride ridge waveguide

“…Differences between the efficiencies at 3,4  are due to residual differences between the peak power levels of the two pump waves. [22,23]. The estimated value is two orders of magnitude larger than that of silica, an order of magnitude larger than that of silicon nitride [27], and similar to that of As2S3 [26].…”

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

“…The good agreement between measurements and theoretical prediction suggests that twophoton absorption is the most dominant effect for nonlinear absorption. [37], star [38], pentagons [39], asterisks [40], up-triangle [41], and down-triangle [42].…”

“…Similarly to the two-photon absorption case, there is a theoretical model developed by Sheik-Bahae et al [29,30] that predicts the dispersion of the real part of the third-order susceptibility (χ (3) ) for semiconductors. This model, represented by the solid line in Figure 3, is based on the Kramers-Kronig relation, [37], star [38], pentagons [39], asterisks [40], up-triangle [41], and down-triangle [42].…”

Energy band engineering of InGaN/GaN multi-quantum-well solar cells via AlGaN electron- and hole-blocking layers

“…https://doi.org/10.1063/1.5028530 III-nitride (III-N) materials have seen huge success in both electronics [1][2][3][4][5][6] and optoelectronics, [7][8][9][10][11][12][13][14][15][16] including power diodes, [1][2][3][4][5][6] solid-state lighting, [7][8][9][10][11][12] and integrated photonics. [13][14][15][16] Ternary InGaN alloys, in particular, have emerged in recent years as promising candidates for photovoltaic (PV) applications, [17][18][19][20][21][22] especially for high temperature PV applications, terrestrial photovoltaic thermal (PVT) hybrid solar collector systems, space applications, and top cells in multi-junction (MJ) solar cells. III-N materials' suitability for these device applications arises from their unique intrinsic properties, such as tunable wide bandgaps, a high absorption coefficient, high thermal stability, and outstanding radiation resistance.…”