Long-wavelength quantum and nonlinear photonics

While quantum and nonlinear photonic technologies are typically developed at shorter wavelengths, there are significant opportunities associated with moving to longer wavelengths. They are particularly valuable for sensing, classical and non-classical: mid-infrared’s ability to act as a molecular fingerprint holds promise for portable medicine, longwave infrared LIDAR can penetrate greater distances in inclement weather, and terahertz can noninvasively detect complex molecules such as explosives. It is it not only important to develop existing concepts at longer wavelengths, but it is also important to take advantage of the opportunities for when longer wavelengths enable new conceptual advances.

High-Q microresonators in the longwave-infrared, a platform we are investigating for classical and non-classical comb generation [1]

Optical-pump terahertz probe measurements of quantum material heterostructures [2]

Frequency-modulated combs, combs that we discovered can be described as ‘extendons,’ nonlinear waves that have constant intensity and represent the opposite of a soliton [3]


  1. Ren, D., Dong, C. & Burghoff, D. High-Q longwave infrared microresonators based on a non-epitaxial germanium platform. arXiv:2111.00362 (2021).
  2. Xiao, Z., Wang, J., Liu, X., Assaf, B. & Burghoff, D. Optical-pump terahertz-probe spectroscopy of the topological crystalline insulator Pb1-xSnxSe through the topological phase transition. arXiv:2111.03183 (2021).
  3. Burghoff, D., “Unraveling the origin of frequency modulated combs using active cavity mean-field theory,” Optica 7, 1781–1787 (2020). (pdf, Optica Top Downloads)