All Stories

  1. Process and material constraints of additive manufacturing for fabrication of terahertz quasi-optical components

    Article • Applied Materials Today, February 2025, Elsevier

    Dr Alexander Valavanis

  2. Power stabilization of a terahertz-frequency quantum-cascade laser using a photonic-integrated modulator

    Article • Optics Express, August 2024, Optical Society of America (OSA)

    Dr Alexander Valavanis

  3. Real-Time Analysis of THz Quantum-Cascade Laser Signals using a Field Effect Transistor Array

    Article • September 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  4. Amplitude Stabilization of a THz Quantum-Cascade Laser using a Photonic Integrated Circuit

    Article • September 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  5. Implementation of a multi-element detector consisting of an 8x8 network of patch-antenna-coupled TeraFETs for gas spectroscopy with THz-QCLs

    Article • September 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  6. Integration of a 2.1-THz Quantum Cascade Laser within an IEEE WM-130 Rectangular Metallic Waveguide

    Article • September 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  7. Real-Time Terahertz Absorption Spectroscopy of Methanol and Deuterated-Methanol Vapour, using a TeraFET Detector Array

    Article • September 2023, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  8. Acoustic band engineering in terahertz quantum-cascade lasers and arbitrary superlattices

    Article • Physical Review B, June 2023, American Physical Society (APS)

    Dr Alexander Valavanis

  9. Waveguide integration of a >4.7‐THz quantum‐cascade laser

    Article • Electronics Letters, January 2023, the Institution of Engineering and Technology (the IET)

    Dr Alexander Valavanis

  10. Extracting Material Properties from a Liquid Crystal Cell Using Terahertz Spectroscopy

    Article • August 2022, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  11. Development of Advanced Terahertz Optics Using Liquid Crystals

    Article • August 2021, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  12. Waveguide integrated terahertz quantum-cascade laser systems

    Article • August 2021, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  13. All-Electronic Phase-Resolved THz Microscopy Using the Self-Mixing Effect in a Semiconductor Laser

    Article • ACS Photonics, March 2021, American Chemical Society (ACS)

    Dr Alexander Valavanis

  14. High-speed modulation of terahertz quantum cascade lasers by acoustic phonon pulses

    Article • March 2021, SPIE

    Dr Alexander Valavanis

  15. Broadband Terahertz Gas Spectroscopy Through Multimode Self-Mixing in a Quantum Cascade Laser

    Article • January 2021, Springer Science + Business Media

    Dr Alexander Valavanis

  16. Spectral analysis of a gas-phase reaction using self-mixing in a terahertz quantum cascade laser

    Article • November 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  17. Quantum Transmission Line Modeling and Experimental Investigation of the Output Characteristics of a Terahertz Quantum Cascade Laser

    Article • IEEE Transactions on Terahertz Science and Technology, July 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  18. Corrections to “Temperature-Dependent High-Speed Dynamics of Terahertz Quantum Cascade Lasers”

    Article • IEEE Journal of Selected Topics in Quantum Electronics, March 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  19. High-speed modulation of a terahertz quantum cascade laser by coherent acoustic phonon pulses

    Article • Nature Communications, February 2020, Springer Science + Business Media

    Dr Alexander Valavanis

  20. Corrections to “Mode Selection and Tuning Mechanisms in Coupled-Cavity Terahertz Quantum Cascade Lasers” [Jul/Aug 17 Art. no. 1200312]

    Article • IEEE Journal of Selected Topics in Quantum Electronics, January 2020, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  21. Broadband terahertz gas spectroscopy through multimode self-mixing in a quantum cascade laser

    Article • September 2019, SPIE

    Dr Alexander Valavanis

  22. Electromagnetic-field analysis of diagonal-feedhorn antennas for terahertz-frequency quantum-cascade laser integration

    Article • September 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  23. High-Speed Modulation of a Terahertz Quantum Cascade Laser Using Coherent Acoustic Phonon Pulses

    Article • September 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  24. Probing Ultrafast Switch-on Dynamics of Frequency Tuneable Semiconductor Lasers Using Terahertz Time-domain Spectroscopy

    Article • July 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  25. Sensing and imaging using laser feedback interferometry with quantum cascade lasers

    Article • Applied Physics Reviews, June 2019, American Institute of Physics

    Dr Alexander Valavanis

  26. 3.5 THz quantum-cascade laser emission from dual diagonal feedhorns

    Article • International Journal of Microwave and Wireless Technologies, May 2019, Cambridge University Press

    Dr Alexander Valavanis

  27. Waveguide-integrated THz Quantum-Cascade Lasers for Atmospheric-Research Satellite Payloads

    Article • May 2019, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  28. Development of Terahertz Quantum-Cascade Lasers for Satellite-Borne Measurement of Key Gas Species

    Article • January 2019, Optical Society of America (OSA)

    Dr Alexander Valavanis

  29. Gas spectroscopy through multimode self-mixing in a double-metal terahertz quantum cascade laser

    Article • Optics Letters, December 2018, Optical Society of America (OSA)

    Dr Alexander Valavanis

  30. Author Correction: Ultrafast switch-on dynamics of frequency-tuneable semiconductor lasers

    Article • Nature Communications, November 2018, Springer Science + Business Media

    Dr Alexander Valavanis

  31. Ultrafast switch-on dynamics of frequency-tuneable semiconductor lasers

    Article • Nature Communications, August 2018, Springer Science + Business Media

    Dr Alexander Valavanis

  32. Continuous Frequency Tuning with near Constant Output Power in Coupled Y-Branched Terahertz Quantum Cascade Lasers with Photonic Lattice

    Article • ACS Photonics, June 2018, American Chemical Society (ACS)

    Dr Alexander Valavanis

  33. Gas spectroscopy with integrated frequency monitoring through self-mixing in a terahertz quantum-cascade laser

    Article • Optics Letters, May 2018, Optical Society of America (OSA)

    Dr Alexander Valavanis

  34. Frequency Tuning Range Control in Pulsed Terahertz Quantum-Cascade Lasers: Applications in Interferometry

    Article • IEEE Journal of Quantum Electronics, April 2018, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  35. Silver-based surface plasmon waveguide for terahertz quantum cascade lasers

    Article • Optics Express, February 2018, Optical Society of America (OSA)

    Dr Alexander Valavanis

  36. 3.5-THz quantum-cascade laser emission from dual diagonal feedhorns

    Article • January 2018, the Institution of Engineering and Technology (the IET)

    Dr Alexander Valavanis

  37. Continuous Frequency Tuning of Y-Branched Terahertz Quantum Cascade Lasers with Photonic Lattice

    Article • January 2018, Optical Society of America (OSA)

    Dr Alexander Valavanis

  38. Coherent vertical electron transport and interface roughness effects in AlGaN/GaN intersubband devices

    Article • Journal of Applied Physics, December 2015, American Institute of Physics

    Dr Alexander Valavanis

  39. Mechanically robust waveguide-integration and beam shaping of terahertz quantum cascade lasers

    Article • Electronics Letters, June 2015, the Institution of Engineering and Technology (the IET)

    Dr Alexander Valavanis

  40. Efficient prediction of terahertz quantum cascade laser dynamics from steady-state simulations

    Article • Applied Physics Letters, April 2015, American Institute of Physics

    Dr Alexander Valavanis

  41. High-contrast coherent terahertz imaging of porcine tissue via swept-frequency feedback interferometry

    Article • Biomedical Optics Express, October 2014, Optical Society of America (OSA)

    Professor H. Peter Soyer, Dr Alexander Valavanis

  42. THz QCL self-mixing interferometry for biomedical applications

    Article • September 2014, SPIE

    Professor H. Peter Soyer, Dr Alexander Valavanis

  43. Discrete Vernier tuning in terahertz quantum cascade lasers using coupled cavities

    Article • Optics Express, June 2014, Optical Society of America (OSA)

    Dr Alexander Valavanis

  44. Terahertz inverse synthetic aperture radar imaging using self-mixing interferometry with a quantum cascade laser

    Article • Optics Letters, April 2014, Optical Society of America (OSA)

    Dr Alexander Valavanis

  45. Terahertz quantum cascade lasers with >1 W output powers

    Article • Electronics Letters, February 2014, the Institution of Engineering and Technology (the IET)

    Dr Alexander Valavanis

  46. Comparative study of intersubband absorption in AlGaN/GaN and AlInN/GaN superlattices: Impact of material inhomogeneities

    Article • Physical Review B, December 2013, American Physical Society (APS)

    Dr Alexander Valavanis

  47. Stable perfectly-matched-layer boundary conditions for finite-difference time-domain simulation of acoustic waves in piezoelectric crystals

    Article • Journal of Computational Physics, November 2013, Elsevier

    Dr Alexander Valavanis

  48. Coherent three-dimensional terahertz imaging through self-mixing in a quantum cascade laser

    Article • Applied Physics Letters, October 2013, American Institute of Physics

    Dr Alexander Valavanis

  49. Self-mixing effect in THz quantum cascade lasers: Applications in sensing and imaging

    Article • October 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  50. Swept-frequency feedback interferometry using terahertz frequency QCLs: a method for imaging and materials analysis

    Article • Optics Express, September 2013, Optical Society of America (OSA)

    Dr Alexander Valavanis

  51. Simulated effect of epitaxial growth variations on THz emission of SiGe/Ge quantum cascade structures

    Article • September 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  52. Spectroscopic analysis of powders through diffuse-reflectance imaging using a frequency-switchable terahertz quantum cascade laser

    Article • September 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  53. Transient analysis of substrate heating effects in a terahertz quantum cascade laser using an ultrafast NbN superconducting detector

    Article • September 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  54. Time-resolved measurement of pulse-to-pulse heating effects in a terahertz quantum cascade laser using an NbN superconducting detector

    Article • Applied Physics Letters, August 2013, American Institute of Physics

    Dr Alexander Valavanis

  55. Terahertz quantum cascade lasers with thin resonant-phonon depopulation active regions and surface-plasmon waveguides

    Article • Journal of Applied Physics, March 2013, American Institute of Physics

    Dr Alexander Valavanis

  56. (Invited) Germanium/Silicon Heterostructures for Terahertz Emission

    Article • ECS Transactions, March 2013, The Electrochemical Society

    Dr Alexander Valavanis

  57. Transient Analysis of THz-QCL Pulses Using NbN and YBCO Superconducting Detectors

    Article • IEEE Transactions on Terahertz Science and Technology, March 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  58. Self-Mixing Interferometry With Terahertz Quantum Cascade Lasers

    Article • IEEE Sensors Journal, January 2013, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  59. Optical absorption in highly strained Ge/SiGe quantum wells: The role of Γ→Δ scattering

    Article • Journal of Applied Physics, December 2012, American Institute of Physics

    Dr Alexander Valavanis

  60. Self-mixing signals in terahertz lasers

    Article • December 2012, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  61. Ultra-fast sampling of terahertz pulses from a quantum cascade laser using superconducting antenna-coupled NbN and YBCO detectors

    Article • September 2012, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  62. Resonant-phonon depopulation terahertz quantum cascade lasers and their application in spectroscopic imaging

    Article • Semiconductor Science and Technology, August 2012, Institute of Physics Publishing

    Dr Alexander Valavanis

  63. Extended density-matrix model applied to silicon-based terahertz quantum cascade lasers

    Article • Physical Review B, June 2012, American Physical Society (APS)

    Dr Alexander Valavanis

  64. Terahertz sensing and imaging using a quantum cascade laser

    Article • October 2011, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  65. Design of Ge/SiGe quantum cascade lasers using the density matrix model

    Article • September 2011, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  66. Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers

    Article • Applied Physics Letters, August 2011, American Institute of Physics

    Dr Alexander Valavanis

  67. Terahertz imaging through self-mixing in a quantum cascade laser

    Article • Optics Letters, July 2011, Optical Society of America (OSA)

    Dr Alexander Valavanis

  68. Material configurations forn-type silicon-based terahertz quantum cascade lasers

    Article • Physical Review B, May 2011, American Physical Society (APS)

    Dr Alexander Valavanis

  69. Finite difference method for solving the Schrödinger equation with band nonparabolicity in mid-infrared quantum cascade lasers

    Article • Journal of Applied Physics, December 2010, American Institute of Physics

    Dr Alexander Valavanis

  70. Design of Ge–SiGe Quantum-Confined Stark Effect Electroabsorption Heterostructures for CMOS Compatible Photonics

    Article • Journal of Lightwave Technology, November 2010, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  71. Design of Ge/SiGe quantum-confined Stark effect modulators for CMOS compatible photonics

    Article • February 2010, SPIE

    Dr Alexander Valavanis

  72. The importance of electron temperature in silicon-based terahertz quantum cascade lasers

    Article • Applied Physics Letters, September 2009, American Institute of Physics

    Dr Alexander Valavanis

  73. Growth variation effects in SiGe-based quantum cascade lasers

    Article • Journal of Optics A Pure and Applied Optics, March 2009, Institute of Physics Publishing

    Dr Alexander Valavanis

  74. Theory and design of quantum cascade lasers in (111)n-type Si/SiGe

    Article • Physical Review B, July 2008, American Physical Society (APS)

    Dr Alexander Valavanis

  75. Intersubband carrier scattering inn- andp−Si∕SiGequantum wells with diffuse interfaces

    Article • Physical Review B, February 2008, American Physical Society (APS)

    Dr Alexander Valavanis

  76. Simulated [111] Si–SiGe terahertz quantum cascade laser

    Article • Applied Physics Letters, January 2008, American Institute of Physics

    Dr Alexander Valavanis

  77. Substrate orientation and alloy composition effects in n-type SiGe quantum cascade structures

    Article • January 2008, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis

  78. Intervalley splitting and intersubband transitions inn-typeSi∕SiGequantum wells: Pseudopotential vs. effective mass calculation

    Article • Physical Review B, May 2007, American Physical Society (APS)

    Dr Alexander Valavanis

  79. Vertical spinal electronic device with large room temperature magnetoresistance

    Article • IEEE Transactions on Magnetics, October 2005, Institute of Electrical & Electronics Engineers (IEEE)

    Dr Alexander Valavanis