Detection and measurement of electroreflectance on quantum cascade laser device using Fourier transform infrared microscope

Abstract

We demonstrate the use of a Fourier Transform Infrared microscope system to detect and measure electroreflectance (ER) from mid-infrared quantum cascade laser (QCL) device. To characterize intersubband transition (ISBT) energies in a functioning QCL device, a microscope is used to focus the probe on the QCL cleaved mirror. The measured ER spectra exhibit resonance features associated to ISBTs under applied electric field in agreement with the numerical calculations and comparable to observed photocurrent, and emission peaks. The method demonstrates the potential as a characterization tool for QCL devices.

Волновые Функции И Собственные Значения Носителей Заряда В Нанотрубке В Окрестности Точки Дирака При Наличии Продольного Электрического Поля

“…Аналогичным образом записывается решение второго из уравнений (16). Из формулы (20) видно, что вблизи точки Дирака при условии |eW 0 ξ| |ε| набег фазы определяется волновым числом k F в точке Ферми.…”

“…В работе [16] [16] можно получить, если учесть, что E − E 0 → 0 вблизи поверхности Ферми. В этом случае в (18) ν = 0, а второе слагаемое в уравнении (18) по абсолютной величине значительно превосходит первое.…”

MOVPE-Grown Quantum Cascade Laser Structures Studied by Kelvin Probe Force Microscopy

“…Taking into account that thicknesses of individual layers in a QCL active region can be just a few atomic monolayers and the total number of individual layers is typically many hundreds, the control of the above parameters in QCLs is even more difficult. Various experimental techniques are used to assess the structural, electrical, optical and thermal properties of the as-grown material and fabricated devices, e.g., [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] in order to help to optimize the QCL design and related epitaxial growth technologies. In this paper, we present a technique for direct, high-spatial-resolution measurements of the voltage distribution across all the parts of QCL structures.…”

Influence of Fröhlich Interaction on Intersubband Transitions of InGaAs/InAlAs-Based Quantum Cascade Detector Structures Investigated by Infrared Modulated Photoluminescence

“…Current reported methods include transmission spectroscopy, [6,20,21] photocurrent (PC) spectroscopy, [15,22] and electroreflectance (ER). [23] For transmission spectroscopy, QCD samples need to be polished into 45 ∘ multipass waveguides to improve the coupling efficiency of the incident probe, which increases the difficulty of sample preparation for transmission measurements. [20] For PC spectroscopy, the preparation of specific geometry devices, such as photolithography, wet etching, and evaporating metal contacts, [24] is also cumbersome but a larger problem is the heating effect and/or carrier depletion of ground states caused by the applied DC bias may disturb the characterization of QCD subbands.…”

“…ER is one of the forms of modulation spectroscopy that has been successfully applied in studying the subband structure of quantum cascade lasers (QCLs). [23] However, the internal perturbed electric field in the ER measurement conflicts with the zero bias operation mode of QCDs. Hence, ER is also unsuitable for characterizing QCD subbands.…”