Optical index measurement of InAs/GaSb type-II superlattice for mid-infrared photodetection at cryogenic temperatures

E. Steveler; M. Verdun; B. Portier; P. Chevalier; C. Dupuis; N. Bardou; J. B. Rodriguez; R. Haïdar; F. Pardo; J. L. Pelouard

doi:10.1063/1.4897273

Optical index measurement of InAs/GaSb type-II superlattice for mid-infrared photodetection at cryogenic temperatures

E. Steveler, M. Verdun, B. Portier, P. Chevalier, C. Dupuis, N. Bardou, J. B. Rodriguez, R. Haïdar, F. Pardo, J. L. Pelouard

Research output: Contribution to journal › Article › peer-review

Abstract

The complex optical index ñ (=n + i κ) of InAs/GaSb type-II superlattice (T2SL) was determined in the 1-6 μm range from reflectivity measurements of resonant structures at 80 K. Several air/superlattice/gold cavities of various thicknesses were fabricated and their reflectivity was measured. As the large variations induced by the cavity resonances in the studied range can be accurately modeled, we were able to determine the complex optical index ñ of InAs/GaSb T2SL with an error of only a few percent. We found that the in-plane refractive index n of the T2SL lies between 3.65 and 3.77 in the mid-infrared wavelength range, and the absorption coefficient κ decreases from 0.23 to 0.001 as the wavelength increases from 1.25 to 5.65 μm. The subtractive Kramers-Kronig relation allowed us to verify our determination of ñ.

Original language	English
Article number	141103
Journal	Applied Physics Letters
Volume	105
Issue number	14
DOIs	https://doi.org/10.1063/1.4897273
Publication status	Published - 6 Oct 2014
Externally published	Yes

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@article{2bdd27bd736346c087e6ca43b59b98c6,

title = "Optical index measurement of InAs/GaSb type-II superlattice for mid-infrared photodetection at cryogenic temperatures",

abstract = "The complex optical index {\~n} (=n + i κ) of InAs/GaSb type-II superlattice (T2SL) was determined in the 1-6 μm range from reflectivity measurements of resonant structures at 80 K. Several air/superlattice/gold cavities of various thicknesses were fabricated and their reflectivity was measured. As the large variations induced by the cavity resonances in the studied range can be accurately modeled, we were able to determine the complex optical index {\~n} of InAs/GaSb T2SL with an error of only a few percent. We found that the in-plane refractive index n of the T2SL lies between 3.65 and 3.77 in the mid-infrared wavelength range, and the absorption coefficient κ decreases from 0.23 to 0.001 as the wavelength increases from 1.25 to 5.65 μm. The subtractive Kramers-Kronig relation allowed us to verify our determination of {\~n}.",

author = "E. Steveler and M. Verdun and B. Portier and P. Chevalier and C. Dupuis and N. Bardou and Rodriguez, \{J. B.\} and R. Ha{\"i}dar and F. Pardo and Pelouard, \{J. L.\}",

note = "Publisher Copyright: {\textcopyright} 2014 AIP Publishing LLC.",

year = "2014",

month = oct,

day = "6",

doi = "10.1063/1.4897273",

language = "English",

volume = "105",

journal = "Applied Physics Letters",

issn = "0003-6951",

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TY - JOUR

T1 - Optical index measurement of InAs/GaSb type-II superlattice for mid-infrared photodetection at cryogenic temperatures

AU - Steveler, E.

AU - Verdun, M.

AU - Portier, B.

AU - Chevalier, P.

AU - Dupuis, C.

AU - Bardou, N.

AU - Rodriguez, J. B.

AU - Haïdar, R.

AU - Pardo, F.

AU - Pelouard, J. L.

PY - 2014/10/6

Y1 - 2014/10/6

N2 - The complex optical index ñ (=n + i κ) of InAs/GaSb type-II superlattice (T2SL) was determined in the 1-6 μm range from reflectivity measurements of resonant structures at 80 K. Several air/superlattice/gold cavities of various thicknesses were fabricated and their reflectivity was measured. As the large variations induced by the cavity resonances in the studied range can be accurately modeled, we were able to determine the complex optical index ñ of InAs/GaSb T2SL with an error of only a few percent. We found that the in-plane refractive index n of the T2SL lies between 3.65 and 3.77 in the mid-infrared wavelength range, and the absorption coefficient κ decreases from 0.23 to 0.001 as the wavelength increases from 1.25 to 5.65 μm. The subtractive Kramers-Kronig relation allowed us to verify our determination of ñ.

AB - The complex optical index ñ (=n + i κ) of InAs/GaSb type-II superlattice (T2SL) was determined in the 1-6 μm range from reflectivity measurements of resonant structures at 80 K. Several air/superlattice/gold cavities of various thicknesses were fabricated and their reflectivity was measured. As the large variations induced by the cavity resonances in the studied range can be accurately modeled, we were able to determine the complex optical index ñ of InAs/GaSb T2SL with an error of only a few percent. We found that the in-plane refractive index n of the T2SL lies between 3.65 and 3.77 in the mid-infrared wavelength range, and the absorption coefficient κ decreases from 0.23 to 0.001 as the wavelength increases from 1.25 to 5.65 μm. The subtractive Kramers-Kronig relation allowed us to verify our determination of ñ.

U2 - 10.1063/1.4897273

DO - 10.1063/1.4897273

M3 - Article

AN - SCOPUS:84907870639

SN - 0003-6951

VL - 105

JO - Applied Physics Letters

JF - Applied Physics Letters

IS - 14

M1 - 141103

ER -

Optical index measurement of InAs/GaSb type-II superlattice for mid-infrared photodetection at cryogenic temperatures

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