A new method to determine the continuous refractive index of an absorbing film by Generalized Stockwell Transform

Coşkun E., Emir C., Selamet S., Parlak M., Özder S.

Optics and Laser Technology, vol.167, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 167
  • Publication Date: 2023
  • Doi Number: 10.1016/j.optlastec.2023.109711
  • Journal Name: Optics and Laser Technology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Communication Abstracts, Computer & Applied Sciences, INSPEC, Metadex, Civil Engineering Abstracts
  • Middle East Technical University Affiliated: Yes


Generalized Stockwell Transform (GST) was adapted to analyze a transmittance signal to continuously determine the refractive index and extinction coefficient. The process is built by analyzing oscillation frequencies of the transmission signal where oscillations exist. The simulation studies clearly show the advantage of the locally referenced phase property of the presented method. The validity of the method was checked for a CdS thin film. The results determined by the GST method are consistent with the results determined by envelope and other signal analyzing methods, and the literature. The noise and relative error analysis of the method was also discussed.