Abstract
Diffraction of optical waves by an acoustic grating is a well-known phenomenon that enables the design of very versatile devices useful in photonic systems. For example, Acousto-Optic Tuneable Filters (AOTFs) can be dynamically tuned by radio-frequency signals. Among possible material choice, tellurium dioxide crystal is often used for practical applications due to its high efficiency. In such a birefringent material, the anisotropic configuration is often used. A feature of this configuration is the sensitivity to optical input polarisation: a selective coupling between polarized modes occurs. The incident must be polarised and
the diffracted mode polarisation is orthogonal to the incident one.
However, during the design process a very specific operation point can be found that ensures the simultaneous diffraction of both the ordinary and the extraordinary optical modes. In this presentation, we introduce the design of AOTF in birefringent crystals and present the main parameters that are subject to trade-off. Acousto-optic diffraction efficiency is sensitive to the so-called phase matching condition between optical wave and the ultrasonic
wave. The offset from synchronicity is considered introducing a phase mismatch parameter. Diffraction efficiency evolution with respect to Bragg condition offset are illustrated. A custom device is finally presented that ensures simultaneous diffraction of both polarisation modes and compared to experimental results.
the diffracted mode polarisation is orthogonal to the incident one.
However, during the design process a very specific operation point can be found that ensures the simultaneous diffraction of both the ordinary and the extraordinary optical modes. In this presentation, we introduce the design of AOTF in birefringent crystals and present the main parameters that are subject to trade-off. Acousto-optic diffraction efficiency is sensitive to the so-called phase matching condition between optical wave and the ultrasonic
wave. The offset from synchronicity is considered introducing a phase mismatch parameter. Diffraction efficiency evolution with respect to Bragg condition offset are illustrated. A custom device is finally presented that ensures simultaneous diffraction of both polarisation modes and compared to experimental results.
Original language | English |
---|---|
Title of host publication | Proceedings of the 10th Convention of the European Acoustics Association Forum Acusticum 2023 |
Editors | Arianna Astolfi, Francesco Asdrudali, Louena Shtrepi |
Pages | 4935-4938 |
DOIs | |
Publication status | Published - 2024 |
Event | Forum Acusticum 2023: 10th Convention of the European Acoustics Association - Torino, Italy Duration: 11 Sept 2023 → 15 Sept 2023 |
Publication series
Name | Proceedings of Forum Acusticum 2023 |
---|---|
ISSN (Print) | 2221-3767 |
Conference
Conference | Forum Acusticum 2023: 10th Convention of the European Acoustics Association |
---|---|
Country/Territory | Italy |
City | Torino |
Period | 11/09/23 → 15/09/23 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Keywords
- AOTF
- anisotropic diffraction
- unpolarised light