VO2-assisted inverted E-shaped four-stub resonator for performance enhancement of a filter

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2024-10, Vol.130 (10), Article 674
• Main Authors: Chauhan, Diksha, Adhikari, Rammani, Sbeah, Zen, Bhardwaj, Suman, Dwivedi, Ram Prakash
• Format: Article
• Language: English
• Subjects: Bandpass filters; Bandstop filters; Characterization and Evaluation of Materials; Condensed Matter Physics; Electric fields; Integrated circuits; Machines; Manufacturing; Modulation; Nanotechnology; Optical and Electronic Materials; Parameters; Physics; Physics and Astronomy; Processes; Q factors; Resonators; Surfaces and Interfaces; Switching; T shape; Thin Films; Transmittance; Vanadium dioxide; Waveguides
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-024-07847-3

In this paper, a plasmonic filter is realized which consists of a T-shaped stub resonator and two side-coupled rectangular cavities; forming an inverted E-type structure connected to the main waveguide. Initially, the device is investigated for the function of a band stop filter in the telecommunication band. Later, the proposed device is investigated for bandpass filtering application by using Vanadium dioxide as an active material to show the improvement in transmittance, modulation depth, quality factor, and tunability of the device. Vanadium dioxide is filled into all four arms of the inverted E shaped structure. For the OFF-state, the electric field is applied to the T shape structure which are; arm 2 and arm 4 whereas for the ON-state, the electric field is applied to the two-side coupled rectangular cavities named as arm 1 and arm 3. The device has shown its potential application in high-quality factor filtering, switching, and modulation applications in telecommunication bands. The quality factor of 208 and 138.18 is achieved for ON-state and OFF-state respectively, whereas the quality factor is further increased and a high value of 308 is obtained by optimizing the device parameters. An extension ratio of modulation of 18.45 dB is attained which can be further increased to 19.95 dB by changing the width of the cavities. Device optimization is performed to show that the bandwidth and transmittance of the spectrum can be manipulated by changing the device parameters like width, length, and height of the cavities. Additionally, the effect of the Elasto-optic effect is also shown which results in a huge tunability of 650 nm and an increase in the modulation depth to 25.8 dB. The device has demonstrated its potential for use in filtering and switching for photonic integrated circuits.