Metallic slit waveguide for dispersion-free low-loss terahertz signal transmission

Abstract

Transmission characteristics of a metallic waveguide are presented combining negligible dispersion, very low attenuation, and two-dimensional mode confinement. The waveguide is fabricated by sawing a 270μm wide slit through a 40mm wide and 300μm thick silicon slab and subsequent metalization of all faces. Single-mode terahertz pulses propagating through the slit are excited at one end of the waveguide using a photoconductive antenna array and detected with a freely positionable photoconductive probe tip. Low-loss propagation with negligible group velocity dispersion is observed in the 0.1–1.0THz frequency range. Compared to former approaches considerably stronger mode confinement is achieved.

Prospects of 4H-SiC Double Drift Region IMPATT Device as a Photo-Sensitive High-Power Source at 0.7 Terahertz Frequency Regime

“…The dielectric constant of the ribbon is 10 while that of the polymer is 2.04 [17]. through a 140 mm wide and 300 μm thick silicon slabs may be used (see Figure 6) [18]. For higher frequency (3 THz) power transfer, a ribbon-like structure fabricated from ceramic alumina may be utilized [17].…”

THz porous fibers: design, fabrication and experimental characterization

“…A mode-locked Ti:sapphire laser with a pulse width of less than 170 fs, central wavelength of 800 nm and a repetition rate of 76 MHz is used to drive the emitter, a photoconductive array of antennas [20], and the detector. The detector is a center- excited dipole between coplanar strip lines photoconductive switch with a 5 μm gap.…”

THz-TDS using a photoconductive free-space linear tapered slot antenna transmitter

“…Here we focus on the design of a PC-FS-LTSA for near-field edge-coupled THz antenna excitation as an alternative to the standard HRFZ-Si lens. Figure 1 illustrates the PC-FS-LTSA which consists of a photoconductive active-area on SI-GaAs which is edge coupled to a metallic-slit based antenna [16][17][18][19][20][21] (i.e. the FS-LTSA).…”

“…The antenna presented here has some distinct advantages over thin membrane antennas: the metallic-slit based antenna has lower conductor loss due to increased conductor surface area, it is less delicate due to the material and thickness, and the manufacturing process doesn't require harsh etchants (EDP, HF, etc). Other substrate-based antennas [2][3][4] which closely model coplanar strip/slotline configurations can have a total loss of ≈17dB/mm at 1 THz [24], whereas the free-space metallic-slit geometry has a loss of <1dB/mm at 1 THz [16]. To note, these numbers are not representative of all designs, but they illustrate the possible large difference between the expected losses.…”