To accommodate the demand of exponentially increased global wireless data traffic, the prospective data rates for wireless communication in the market place will soon reach 100 Gbit/s and beyond. In the lab environment, wireless transmission throughput has been elevated to the level of over 100 Gbit/s attributed to the development of photonic-assisted millimeter wave (MMW) and THz technologies. However, most of recent demonstrations with over 100 Gbit/s data rates are based on spatial or frequency division multiplexing techniques, resulting in increased system's complexity and energy consumption. Here, we experimentally demonstrate a single channel 0.4 THz photonic-wireless link achieving a net data rate of beyond 100 Gbit/s by using a single pair of THz emitter and receiver, without employing any spatial/frequency division multiplexing techniques. The high throughput up to 106 Gbit/s within a single THz channel is enabled by combining spectrally efficient modulation format, ultra-broadband THz transceiver and advanced digital signal processing (DSP) routine. Besides that, our demonstration from system-wide implementation viewpoint also features high transmission stability, and hence shows its great potential to not only decrease the system's complexity, but also meet the requirements of prospective data rates for bandwidth-hungry short-range wireless applications.

We demonstrate a scheme for long-range, high-precision absolute distance measurement based on frequency detection using two optoelectronic oscillators to convert distance information to frequency information. The two-oscillator design offers the unique advantage of self-referencing. By taking advantage of the accumulative magnification theory, the error of the measured distance is decreased by approximately ${10}^5$ fold, which significantly improves the precision of the measured distance. In our experiments, the maximum error is $\pm 1.5\mathrm{\mu m}$ at an emulated distance of approximately 3.35 km, including a drift error of approximately 1 μm in the air path due to the variation of environmental conditions. The highest relative measurement precision achieved in our current system is $4.5\times {10}^{-10}$.

A novel single longitudinal mode (SLM) Brillouin fiber laser (BFL) with cascaded ring (CR) Fabry-Pérot resonator is proposed and demonstrated. By optimizing the CR length of the single mode fiber cavity at 100 m (or 50 m) and 10 m, stable SLM operation is obtained. Therefore, the threshold power is lower and linewidth is narrower than that of previously reported BFL with 10 m (or 20 m) single cavity. Additionally, there is no additional attenuation except intrinsic loss of optical devices. The measured linewidth with 60 dB (or 45 dB) improved value of side mode suppression ratio is 0.41 kHz (or 3.23 kHz), which is three (or two) orders of magnitude than that of the pump. Using a stabilizing feedback loop based on autotracking technique with polarization maintaining fiber-based optical delay line, the SLM BFL exhibits good performance with 6% power fluctuation in 1 h.

We propose the simple pulse source, in which the pulses generated by large-signal directly modulated laser diode are phase-modulated, and then compressed into short pulses by an optimized length of DCF. On the one hand, phase modulator is used to enhance the negative chirp of large-signal directly modulated pulses. On the other hand, the largesignal directly modulated pulses are used to suppress the pedestal produced by the phase modulator. Using this technique, highly stable 10-GHz 5.5-ps optical pulses are obtained, which suppress pedestal up to 20dB and have a low timing jitter of 184fs.

Under the conventional scheme to generate an optical frequency comb (OFC) using an electro-optic modulator (EOM), the frequency interval of the OFC is determined via the frequency of the fundamental tone of the radio frequency (RF) driving signals. In this work, we use two harmonics without the fundamental tone to drive two EOMs, where the frequency interval of the generated flat OFC is the frequency of the fundamental tone. The orders of the two harmonics are coprime. Specifically, one harmonic drives the first branch of the dual-parallel Mach–Zehnder modulator (DPMZM) only, and the other harmonic drives the phase modulator (PM). The flatness of the OFC is achieved by adjusting the amplitude and phase of the RF driving harmonics as well as the bias of the EOM. Both a simulation and an experiment were carried out to verify the effectiveness of the proposed scheme. When the second harmonic drives the DPMZM and the third harmonic drives the PM, an 11-comb line OFC is generated, where the flatness of the OFC was 0.63 dB and 0.65 dB under the simulation and experiment, respectively. When the third harmonic drives the DPMZM and the second harmonic drives the PM, a 13-comb line OFC is generated, where the flatness of the OFC was 0.62 dB and 0.95 dB under the simulation and experiment, respectively. We also investigate the performance of the generated OFC when one harmonic drives two branches of the DPMZM and the other harmonic drives the PM. The comparison of the OFCs’ performance demonstrates the effectiveness of the proposed scheme.

Simultaneous regeneration of four high-speed (160 Gbit/s) wavelength-division multiplexed (WDM) and polarization-division multiplexed (PDM) signals in a single highly nonlinear fiber (HNLF) is demonstrated. The regeneration operation is based on four-wave mixing in HNLF, where the degraded data signals are applied as the pump. As a result, the noise on both ‘0’ and ‘1’ levels can be suppressed simultaneously in our scheme. The stimulated Brillouin scattering (SBS) from the continuous wave (CW) is suppressed by cross-phase modulation (XPM) from the data pump, relieving the requirement of external phase modulation of the CW light. Mitigation of the inter-channel nonlinearities is achieved mainly through an inter-channel 0.5 bit slot time delay. Bidirectional propagation is also applied to relieve the inter-channel four-wave mixing. The multi-channel regeneration performance is validated by bit-error rate (BER) measurements. The receiver powers at the BER of 10⁻⁹ are improved by 1.9 dB, 1.8 dB, 1.6 dB and 1.5 dB for the four data channels, respectively.