H. Nickel

Refractive indices of InAlAs and InGaAs/InP from 250 to 1900 nm determined by spectroscopic ellipsometry

Abstract 2 μm thick layers of MBE-grown In0.53Ga0.47As and In0.52Al0.48As on InP are measured with spectroscopic ellipsometry in the wavelength range from 245 to 845 nm and the fitted n,k dispersion curves given. From 450 to 845 nm the real and imaginary part of the refractive index of In0.52Al0.48As are about 0.1 higher than those of InP. The angle of incidence of two ellipsometers are controlled by measuring the same sample at different wavelengths and a correction for one ellipsometer is made. About 0.5 μm thick In0.53Ga0.47As and In0.52Al0.48As layers on InP are measured in the same manner and in addition from 410 to 1900 nm to determine the n,k values for this wavelength range. For the fitting procedure an interface layer between the substrate and the ternary layer is necessary. First results are given.

Spectroscopic ellipsometry: a useful tool to determine the refractive indices and interfaces of In0.52Al0.48As and In0.53AlxGa0.47−xAs layers on InP in the wavelength range 280–1900 nm

Abstract In0.52Al0.48As and In0.53AlxGa0.47−xAs layers on InP are promising quaternary materials for optoelectronic devices: lasers containing these materials have been realized and show excellent performance. The refractive indices of both In0.52Al0.458Ga0.022As and In0.53Al0.055Ga0.415As are measured for the first time with multiple angle spectroscopic ellipsometry in the wavelength range 280–1900 nm.

InxGa1-xAs/GaAs pseudomorphic quantum wells - growth and thermal stability

Abstract We have optimized the MBE growth conditions of InGaAs/GaAs pseudomorphic structures in order to obtain narrow emission linewidths and high quantum efficiencies. The thermal stability of the strained layers is studied using annealing at T ⩽930 °C. From the evaluation of the luminescence spectra after 30 min annealing we estimate an In/Ga interdiffusion length of about 2 nm at 900° C.

Design and realization of InGaAs/GaAs strained layer DFB quantum well lasers

Optical waveguiding in an InGaAs/GaAs strained-layer distributed feedback (DFB) quantum well laser is investigated using the one-dimensional shooting method presented. The numerical approach is used to optimize the waveguide geometry and to calculate the corrugation period and the coupling factor for the integrated Bragg grating. The quantum well DFB structure designed according to the numerical calculations for an emission wavelength of 982 nm was realized for the first time entirely by molecular beam epitaxy (MBE) growth. Thus, side-mode suppression ratios of 49 dB, threshold currents of 7 mA and quantum efficiencies of 0.4 mW/mA were achieved. >

Determination of refractive indices of In0.53Al0.40Ga0.07As and In0.53Al0.11Ga0.36As on InP in the wavelength range from 280 to 1900 nm by spectroscopic ellipsometry

The refractive indices of In 0.53 Al 0.40 Ga 0.07 As and In 0.53 Al 0.11 Ga 0.36 As layers on InP are measured for the first time by spectroscopic ellipsometry in the wavelength range from 280 to 1900 nm. In previous papers we found out that between InP and MBE-grown In 0.52 Al 0.48 As and In 0.53 Ga 0.47 As layers an interface layer exists, due to the interaction of arsenic with InP in the preheat phase of the MBE growth. We investigated three layers of each composition with different thicknesses for the determination of the refractive indices and the exact values of the thicknesses

Spectroscopic ellipsometry : a useful tool to determine the refractive indices and interfaces of In0.52Al0.48As and In0.53AlxGa0.47-xAs on InP in the wavelength range from 280 to 1900 nm

Abstract The refractive indices of layers of the quaternary materials In 0.53 Al 0.21 Ga 0.26 As and In 0.53 Al 0.31 Ga 0.16 As on InP are measured for the first time by spectroscopic ellipsometry in the wavelength range from 280 to 1900 nm. In previous papers we found out that between InP and molecular beam epitaxy (MBE) grown In 0.52 Al 0.48 As, In 0.53 Al 0.405 -Ga 0.065 As, In 0.53 Al 0.11 Ga 0.36 As, and In 0.53 Ga 0.47 As layers an interface layer exists, owing to the exchange of phosphorus and arsenic atoms during the As 4 -stabilized oxide desorption procedure before the MBE growth. We investigated two layers (with different thicknesses) of each composition for the determination of the refractive indices and the exact values of the thicknesses.

Determination of refractive indexes of In0.52Al0.48As on InP in the wavelength range from 250 to 1900 nm by spectroscopic ellipsometry

Abstract In a previous paper, we found that between InP and In 0.52 Al 0.48 As grown by molecular beam epitaxy, an interface layer exists, owing to the interaction of arsenic with InP in the preheat phase of the MBE growth. To determine the refractive index and thicknesses of the In 0.52 Al 0.48 As and the interface layer in the wavelength range from 300 to 1900 nm, layers 10, 20, 200 and 2000 nm thick of MBE-grown In 0.52 Al 0.48 As on InP were investigated using spectroscopic ellipsometry.

MBE grown strained and unstrained InGaAs/InAlGaAs MQW lasers

The authors demonstrated the growth and reproducibility of various molecular beam epitaxy InAlGaAs/InGaAs 1.5/spl mu/m separate confinement heterostructure and graded index separate confinement heterostructure multi quantum well (MQW) laser diodes with lattice matched or compressively strained QWs. Various fundamental material and laser properties were studied for Fabry Perot and distributed feedback lasers. Epitaxial regrowth on Al-containing layers is described.<<ETX>>

Determination of the refractive index of In0.53Al0.11Ga0.36As on InP in the wavelength range from 280 to 1900 nm by spectroscopic ellipsometry

The refractive index of the quarternary material In 0.53 Al 0.11 Ga 0.36 As/InP is measured for the first time by spectroscopic ellipsometry in the wavelength range from 280 to 1900 nm. In previous papers we found out that between InP and MBE-grown In 0.52 Al 0.48 As or In 0.53 Ga 0.47 As an interface layer exists, due to the interaction of arsenic with InP in the preheat phase of the MBE growth. Therefore we grew three layers of In 0.53 Al 0.11 Ga 0.36 As on InP with different thicknesses to determine the refractive indices and exact values of the thicknesse

Study of In0.53Ga0.47As/In0.52Al0.48As quantum wells on InP by spectroscopic ellipsometry and photoluminescence

Abstract inGaAs/InAIAs quantum wells of different well widths were measured by multiple angle of incidence spectroscopic ellipsometry in the wavelength range from 280 to 865 nm. Comparing the experimental data to the calculated results of a theoretical seven-layer model using our refractive index ( n - i k ) curves of the materials involved in our structures, we determined all the layer thicknesses, especially the InGaAs well widths. For our samples, in addition, low temperature photoluminescence studies were performed and compared to the results of potential well calculations. A good agreement is obtained between the well widths determined by ellipsometry and photoluminescence, respectively. Thin interface layers, embedding the InGaAs quantum wells are not observed in the wavelength range from 280 to 700 nm.