Fig 7 - uploaded by Li Yi
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The schematic diagram of the experimental setup. EDFA, erbium-doped fiber amplifier; PPG, pulse-pattern generator; OBPF, optical band-pass filter; OSA, optical spectrum analyzer; VOA, variable optical attenuator.
Context in source publication
Context 1
... we face the similar phase noise problem in the receiver, where the SHM pumped by the frequency-multiplied signal source is used, it is fair to compare its performance with the OFCG-based source which was commonly used in our previous research. Figure 7 shows a schematic diagram of the QPSK communication experiment. Both SBS and OFCG-based sources were applied for comparison, the receiver configuration remained the same. ...
Citations
... In the multi-level signal modulation schemes, when the multi-level number increases, not only higher signal-tonoise ratio (SNR) but also reduction in the phase noise of radio frequency (RF) and local oscillator (LO) signals are required in the sub-THz communications systems [14][15][16]. Against this background, we proposed the use of a low-noise photonic sub-THz signal generator using a stimulated Brillouin scattering (SBS) light source for RF signals [17], and for both the RF and LO signals [18]. In the latter system, the maximum data rate was 80 Gbit/s with 16QAM at 300 GHz. ...
... As is already pointed out that the phase noise affects the BER characteristics of the communication systems [13][14][15][16][17], it could be concluded that the difference in the BER characteristics of Fig. 5 is related to the difference in the phase noise between the two LO signal sources. ...
We present a sub-terahertz (THz) wireless link using photonics-based ultra-low phase noise transmitter and receiver. The maximum data rate achieved below hard-decision forward error correction (HD-FEC) threshold by using on-line signal processing was 240 Gbit/s with 64 quadrature amplitude modulation (64QAM) at a single carrier frequency of 275 GHz. We also demonstrate successful 20-m transmission at a data rate of over-200 Gbit/s data rate. This is the highest single-channel performance ever reported with sub-THz wireless communications to the best of our knowledge.
... Millimeter-wave and TeraHertz generation with state-of-the-art noise performance in chip-scale form factor will undeniably stimulate a plethora of civilian and defense applications including high-resolution radar [1], non-destructive imaging [2], 5G and 6G cellular network deployment [3], wireless communication [4,5], global navigation system [6], satellite communication [7] as well as fundamental science with applications such as radioastronomy [8,9], and rotational spectroscopy [10,11]. While millimeter-wave oscillators based on complementary metal-oxide-semiconductor (CMOS) technology have shown spectacular performance in terms of size and power consumption, power spectral density of phase noise performance is lacking [12]. ...
In this letter, we experimentally demonstrate low noise 300GHz wave generation based on a Kerr microresonator frequency comb operating in soliton regime. The spectral purity of a 10GHz GPS-disciplined dielectric resonant oscillator is transferred to the 300GHz repetition rate frequency of the soliton comb through an optoelectronic phase-locked loop. Two adjacent comb lines beat on a uni-travelling carrier photodiode emitting the 300GHz millimeter-wave signal into a waveguide. In an out-of-loop measurement we have measured the 300GHz power spectral density of phase noise to be -88dBc/Hz, -105dBc/Hz at 10kHz, 1MHz Fourier frequency, respectively. The free-running fractional frequency instability at 300GHz is $1 \times 10^{-9}$ at 1 second averaging time. Stabilized to a GPS signal, we report an in-loop residual instability of $2 \times 10^{-15}$ at 1 second which averages down to < $1 \times 10^{-17}$ at 1000 seconds. Such system provides a promising path to the realization of compact, low power consumption millimeter-wave oscillators with low noise performance for out-of-the-lab applications.
High–speed, high–power photodiodes play a key role in wireless communication systems for the generation of millimeter wave (MMW) and terahertz (THz) waves based on photonics–based techniques. Uni–traveling–photodiode (UTC–PD) is an excellent candidate, not only meeting the above–mentioned requirements of broadband (3 GHz~1 THz) and high–frequency operation, but also exhibiting the high output power over mW–level at the 300 GHz band. This paper reviews the
fundamentals of high–speed, high–power photodiodes, mirror–reflected photodiodes, microstructure photodiodes, photodiode–integrated devices, the related equivalent circuits, and design considerations. Those characteristics of photodiodes and the related photonic–based devices are analyzed and reviewed with comparisons in detail, which provides a new path for these devices with applications in short–range wireless communications in 6G and beyond.
This chapter describes latest advances in THz communication research based on photonic technologies. Photonics-based transmitters and receivers are explained focusing on system configurations and enabling technologies.
