37. savetovanje CIGRE Srbija (2025) SIGURNOST, STABILNOST, POUZDANOST I RESILIENCE ELEKTROENERGETSKOG SISTEMA MULTISEKTORSKO POVEZIVANJE U ENERGETICI I PRIVREDI – D1-04
AUTOR(I) / AUTHOR(S): Milan Ignjatović, Nikola Vuković, Nikola Basta, Aleksandar Milićević, Aleksandar Atić, Aleksandar Demić
DOI: 10.46793/CIGRE37.D1.04
SAŽETAK / ABSTRACT:
A frequency comb is a spectrum of electromagnetic radiation composed of discrete and regularly spaced spectral lines. In the time domain, this spectrum can correspond to a regular train of ultrashort pulses. In an optical frequency comb, the frequency spacing between the different modes lies in the part of the spectrum belonging to radio waves. In this way, a direct connection is established between radio waves and the optical part of the spectrum. Atomic clocks operate in the microwave region of the spectrum, and a frequency comb enables the transfer of the accuracy of such clocks to the optical part of the electromagnetic spectrum. The first frequency combs were implemented using mode-locked lasers. Recently, passive mode locking has been achieved in terahertz quantum cascade lasers using a graphene saturable absorber. Quantum cascade lasers are semiconductor lasers consisting of a multilayer periodic structure that forms an array of quantum wells. Laser emission is achieved via intraband transitions, and population inversion is obtained by applying an external electric field. To simulate the dynamics of quantum cascade lasers, it is necessary to solve Maxwell’s equations for the electromagnetic field in conjunction with the Bloch equations that describe the population of laser levels via the density matrix formalism. The equations have been successfully solved numerically in full form without using the slow-varying field approximation, which increases the number of spatial and time steps in the calculation. Ultrafast and intense terahertz light pulses represent a key technology for the development of materials science, enabling the generation of a frequency comb for high-precision metrology and spectroscopy.
KLJUČNE REČI / KEYWORDS:
frequency comb, quantum cascade laser, Maxwell-Bloch equations
PROJEKAT / ACKNOWLEDGEMENT:
Rezultati ovog rada su dobijeni tokom istraživanja na projektu „Generisanje ultra kratkih impulsa pomoću terahercnog kvantnog kaskadnog lasera koji radi u režimu pasivnog zaključavanja modova sa grafenskim saturabilnim apsorberom“, 10504, finansiranom od strane Fonda za nauku Republike Srbije pri Programu za izvrsne projekte mladih istražvača – PROMIS.
LITERATURA / REFERENCES:
- T. W. Hansch, “Passion for Precision (Nobel Lecture)“, ChemPhysChem, 2006, Vol 7, pp. 1170–1187
- G. Guo et al. “A Review: Application of Terahertz Nondestructive Testing Technology in Electrical Insulation Materials“, IEEE Access, 2022, Vol. 10, pp. 121548-121560
- L. Lugiato, F. Prati, M. Brambilla, “Nonlinear Optical Systems”, Cambridge University Press, 2015
- D. Botez, M. A. Belkin, “Quantum Cascade Lasers”, Cambridge University Press, 2023
- N. Stanojević, A. Demić, N. Vuković, P. Dean, Z. Ikonić, D. Indjin, J. Radovanović, “Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers”, Scientific Reports, 2024, Vol. 14, 5641.
- F. Kartner, J. A. D. Au, U. Keller, “Mode-Locking with Slow and Fast Saturable Absorbers—What’s the Difference?”, IEEE Journal of Selected Topics in Quantum Electronics, 1998, Vol. 4, No.2, pp. 159-168
- E. Riccardi et al. “Short pulse generation from a graphene-coupled passively mode-locked terahertz laser”, Nature Photonics, 2023, Vol. 17, pp. 607-614
- C. Jirauschek, M. Riesch, P. Tzenov, “Optoelectronic Device Simulations based on Macroscopic Maxwell-Bloch Equations”, Adv. Theory Simul. 2020, Vol. 2, 1900018
- L. Seitner et al. “Theoretical model of passive mode-locking in terahertz quantum cascade lasers with distributed saturable absorbers”, Nanophotonics, 2024, Vol. 13, No. 10, pp. 1823-1834.