Design and Optimization of Microbolometer Multilayer Optical Cavity

• Authors: E. Awad , N. Al-Khalli , M. Abdel-Rahman , N. Debbar , M. Alduraibi
• Languages of publication: EN

Abstracts

EN

Microbolometers are the most widely used detectors in long-wave infrared uncooled thermal imagers. An optical cavity is required within a microbolometer structure to increase its optical absorption. In this work we present a detailed study on the design and optimization of a microbolometer optical cavity using Essential-Macleod package. In the simulations, the cavity is considered as thin film multi-layers that form cascaded Fabry-Perot optical cavities. In the design phase, the structures of layers are selected, which includes selection of materials and initial thickness. The absorbing layers are chosen to be made of vanadium-pentoxide (V₂O₅) and titanium (Ti). In the optimization phase, the designed layer thicknesses are varied to maximize optical absorption within the absorbing layers. The simulations show that Ti layer absorption dominates over the V₂O₅ layer. Also, the optimization proves that the thickness of cavity's air-gap is not equal simply to quarter-wavelength, because of the presence of a complex cascaded Fabry-Perot structure. The optimized air-gap thickness is found to be ≈ 3.5 μm at wavelength of 10.6 μm.

Keywords

EN

85.60.Bt; 42.25.Bs

Discipline

• 42.25.Bs: Wave propagation, transmission and absorption[see also 41.20.Jb—in electromagnetism; for propagation in atmosphere, see 42.68.Ay; see also 52.40.Db Electromagnetic (nonlaser) radiation interactions with plasma and 52.38-r Laser-plasma interactions—in plasma physics]
• 85.60.Bt: Optoelectronic device characterization, design, and modeling

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2015
• Volume: 127
• Issue: 4
• Pages: 1295-1297

Dates

published

2015-04

Contributors

author

E. Awad

• Electrical Engineering Department, College of Engineering, King Saud University, Riyadh 11421, KSA

author

N. Al-Khalli

• Electrical Engineering Department, College of Engineering, King Saud University, Riyadh 11421, KSA

author

M. Abdel-Rahman

• Prince Sultan Advanced Technologies Research Institute (PSATRI), College of Engineering, King Saud University, Riyadh 11421, KSA

author

N. Debbar

• Electrical Engineering Department, College of Engineering, King Saud University, Riyadh 11421, KSA

author

M. Alduraibi

• Physics and Astronomy Department, College of Science, King Saud University, Riyadh 11451, KSA
• National Center for Applied Physics, King Abdulaziz City for Science and Technology, KACST, P.O. Box 6086, Riyadh 11442, KSA

References

• [1] P.W. Kruse, Uncooled Thermal Imaging. Arrays, Systems, and Applications, SPIE Press, Bellingham, USA, 2001, doi: 10.1117/3.415351
• [2] Essential-Macleod, http://www.thinfilmcenter.com
• [3] C. Vieider, Proc. of SPIE 6836, 68360D (2007), doi: 10.1117/12.755128
• [4] D. Lohrmann, R. Littleton, C. Reese, D. Murphy, J. Vizgaitis, Opt. Eng. 52(6), 061305 (2013), doi: 10.1117/1.OE.52.6.061305
• [5] Q. Cheng, S. Paradis, T. Bui, M. Almasri, Sensors Journal, IEEE 11, 167 (2011), doi: 10.1109/JSEN.2010.2056364

Identifiers

DOI

10.12693/APhysPolA.127.1295