Presentation Information
[10p-A22-11]Experimental Demonstration of a Terahertz Spectral Drill Cavity
〇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,THz mirror,Cavity
Tunable THz bandpass filters are required to isolate target frequencies and reject crosstalk via continuous spectral tuning. Conventionally, Fabry-Pérot (FP) cavities with regularly spaced axial modes serve as tunable filters or frequency rulers by physically shifting the mirror separation or by applying a drive voltage to an intracavity electro-optic crystal.
In this work, we propose an extension to the FP cavityby including waveplates inside the cavity, a configuration known as the ”spectral drill cavity”. Rotating these waveplates, introduces the Pancharatnam–Berry phase shift to the intracavity light, enabling continuous axial mode tuning independent of optical path length and frequency. While this concept has been demonstrated at a 1.55 µm wavelength, we implement it here for the first time in the THz range using RTD sources combined with custom-made metal mesh mirrors and 3D-printed quarter-wave plates developed in our previous work.
In this work, we propose an extension to the FP cavityby including waveplates inside the cavity, a configuration known as the ”spectral drill cavity”. Rotating these waveplates, introduces the Pancharatnam–Berry phase shift to the intracavity light, enabling continuous axial mode tuning independent of optical path length and frequency. While this concept has been demonstrated at a 1.55 µm wavelength, we implement it here for the first time in the THz range using RTD sources combined with custom-made metal mesh mirrors and 3D-printed quarter-wave plates developed in our previous work.