Experimental demonstration of a THz-to-photonics converter facilitated by electronic IQ mixers and a polarization-multiplexed intensity modulator

To effectively utilize existing fiber infrastructure in wireless-fiber transmission scenarios, especially for potential use in satellite-ground-user links, we propose a novel, to the best of our knowledge, D-band THz-to-photonics converter based on two electronic IQ mixers and a polarization-multiplexed intensity modulator (PM-IM), which enables polarization-insensitive transmissions and results in enhanced performance. With the help of the proposed converter, we successfully demonstrate the experimental transmission of 16-/24-Gbaud quadrature phase shift keying (QPSK) signals over a 2.92-m wireless and 5-km standard single-mode fiber (SSMF) link. Experimental results indicate that the power penalty is measured as 1.1 and 2.9 dB for the two baud rates, respectively, under the 20% soft-decision forward-error-correction (SD-FEC) threshold of 2 × 10 −2 .