Presentation Information
[9a-N204-3]Design of a Silicon-based THz Quarter-wave plate for a Spectral Drill Cavity
〇(M1)Victor Isao Iwanaga1, H. Shirasaka1, S. Hayashi2, K. Miyamoto3, Y. Urata4, K. Nawata5, J. Shikata6, N. Sekine2, S. Ohno1 (1.Tohoku Univ., 2.NICT, 3.Chiba Univ., 4.PHLUXI Inc., 5.Tohoku Inst. of Tech., 6.Nihon Univ.)
Keywords:
THz waveplate
Photonic Landau levels, analogues of electronic Landau levels arising from pseudomagnetic fields, have gained significant attention in fundamental physics. A potential way to reveal their phase information involves constructing a THz Spectral Drill: a geometric phase shifter within a Fabry–Pérot cavity operating in the THz region. In this setup, the rotation of a broadband quarter-wave plate (QWP) is required to achieve continuous axis mode sweeping.
In this work, we present the design of a broadband QWP operating in the THz band, based on a silicon subwavelength grating. Using FDTD simulations, we demonstrate that QWP behaviour can be achieved at selectable frequencies within the range from 0.4 to 1.2 THz, depending on the geometry, with approximately 50% relative bandwidth under a 3% phase tolerance.
For a stricter 0.5% tolerance, designs that produce a disconnected plateau shape in the phase spectrum are proposed, achieving a weighted relative bandwidth of approximately 40%.
In this work, we present the design of a broadband QWP operating in the THz band, based on a silicon subwavelength grating. Using FDTD simulations, we demonstrate that QWP behaviour can be achieved at selectable frequencies within the range from 0.4 to 1.2 THz, depending on the geometry, with approximately 50% relative bandwidth under a 3% phase tolerance.
For a stricter 0.5% tolerance, designs that produce a disconnected plateau shape in the phase spectrum are proposed, achieving a weighted relative bandwidth of approximately 40%.