Organometallic vapour phase epitaxy of galliumarsenide using Ga(CH3)3 · N(CH3)3-adduct as precursor

Epitaxial layers of GaAs have been grown by MOVPE using trimethylgallium-trimethylamin-adduct (TMGa-TMN) as the Ga-precursor. In comparison to the growth system using pure TMGa no significant influence on growth conditions and materials parameters could be found. The deposited GaAs is of fairly high quality with room temperature mobilities of 6700 cm²/Vs at free electron concentrations of about 1 × 10¹⁵ cm⁻³. No hints to nitrogen incorporation could be found.     

Optical waveguiding and nonlinear optical characterization of 2-docosylamino-5-nitropyridine Langmuir-Blodgett films

Well ordered Y-type Langmuir-Blodgett (LB) multilayers of 2-docosylamino-5-nitropyridine (DCANP) have been characterized with linear and nonlinear optical techniques. The nonlinear optical susceptibilities have been determined for the wavelengths λ = 1064 nm (d₃₃ = (7.8±1) pm/V, d₃₁ = (2.0 ± 0.5) pm/V) and λ = 1318 nm (d₃₃ = (5.6 ± 1) pm/V). Waveguiding experiments with grating couplers allowed the excitation of TE_o and TM_o modes propagating over more than 20 mm. Guided wave attenuation coefficients as low as 12 dB/cm (at the wavelength λ = 632.8 nm) are reported. Coupling experiments allowed the determination of the dispersion of the refractive index n₃ (n₃^{632.8 nm} = 1.598). The refractive index data could be used to calculate phase-matching conditions for frequency doubling with TE modes in DCANP waveguides.