Integrated diffractive optical elements for terahertz beam shaping and polarization control /

This doctoral dissertation presents the design, development, and optimization of integrated diffractive optical elements (DOEs) for efficient beam focusing, polarization control and enhanced transparency in the terahertz (THz) frequency range (0.1–1 THz). Utilizing semiconductor- and metal-based elements, the research introduces hybrid multi-phase Fresnel zone plate (H-MPZP) lenses with reduced structural complexity and enhanced focusing performance, high contrast grating (HCG) waveplates with sinusoidal surface modulation for broadband polarization manipulation, and free-standing meta-surfaces composed of subwavelength resonators engineered to exploit electromagnetic coupling and anapole resonances for enhanced transparency and spectral control. Numerical simulations and experimental validations confirm the capability of these compact, lightweight, and integrable elements to deliver high efficiency, reduced reflection losses, and wide operational bandwidths. These findings offer promising pathways for advancing THz photonics in imaging, sensing, communication technologies, and semiconductor-integrated on-chip platforms.

Grantor dc:publisher

Institutional Repository of Vilnius University

Year dc:date

2025

Author dc:creator

• Ayyagari, Surya Revanth,

Contributors dc:contributor

• Kašalynas, Irmantas

• diffractive optical elements ; hybrid multi-phase Fresnel zone plate ; high contrast grating ; free-standing meta-surfaces

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Repository record dc:identifier

https://repository.vu.lt/VU:ELABAETD234991751&prefLang=en_US

OAI identifier oai:identifier

oai:vu.lt:elaba:234991751