Query: SFDR microwave photonics links

title: The effect of two photon absorption on the dynamic range of integrated microwave photonics links
abstract: Recently, Integrated Microwave Photonics (IMWP) on Silicon on Insulator (SOI) platform has attracted much attention. SOI as a platform for passive devices has been studied for operation at a wavelength of 1.55 mm. It has been acknowledged that Si suffers from Two Photon Absorption (TPA) at this wavelength, which potentially limits the dynamic range of microwave photonic links. The TPA effect diminishes at longer wavelengths, and completely vanishes at a wavelength of 2.2 mm. So far, the detailed effects of TPA on the performance of the SOI platform in the context of IMWP have not been well explored. In this work, a systemic simulation has been performed in order to investigate the effects of nonlinear TPA on the performance of SOI microwave photonic links at 1.55 mm, particularly the dynamic range of the system was studied in depth. Furthermore, system performance at wavelengths from 1.55 to 2.2 mm was investigated by scaling the device design, where the parasitic effects of TPA are avoided. Based on theoretical analysis, the result showing microwave photonic links at 2.2 mm outperform that at 1.55 mm was obtained as expected. Strip and rib waveguides at 1.55 mm show P1dB points of 3.75 mW and 69.54 mW, respectively, and at 2.2 mm, these waveguides performed linearly throughout the simulated range (up to 1 W of input power) which is due to the dramatically reduced TPA effect. It is noted that the wavelengths at which SOI avoids parasitic TPA match well with the working wavelengths of emerging GeSn lasers and photodetectors.

title: Elimination of odd and even intermodulation distortions of analog microwave photonics link based on GaAs MZMs.
abstract: In this paper, a high linear Analogue Microwave Photonic Link (AMPL) is proposed and experimentally demonstrated by unique ways of deploying Gallium Arsenide (GaAs) two Electro optic Mach Zehnder Modulators (MZMs) and Balanced Photo detector (BPD) All even and odd intermodulation distortions products are suppressed under noise floor. Second Order Harmonics (SOH) are also significantly suppressed by careful arrangements of microwave shifters and MZMs. The proposed configuration of AMPL is a single side band. We have also developed and implemented a full mathematical model for proposed configuration, and linearization of the system is tested by introducing an additional RF signal. Our experimental measurements exhibit the suppression under the noise floor of all even and odd IMD and significant suppression of SOH. Spurious Free Dynamic Range (SFDR) of the proposed analogue photonic link for a linearized signal is 119.5 dB.Hz2/3. The proposed novel AMPL would have a great impact on future aerospace, defense and satellite to ground downlink communication systems applications.

title: Photonic Generation of Quantum Noise Assisted Cipher at Microwave Frequencies for Secure Wireless Links
abstract: We propose novel wireless physical layer encryption utilizing signal masking by truly random quantum noise. 12 Gbit/s cipher with sufficient masking is generated in 30 GHz band by optical heterodyne, and secure microwave wireless transmission is achieved.

title: A Novel Frequency Modulation (FM) Demodulator for Microwave Photonic Links Based on Polarization Maintaining Fiber Bragg Grating
abstract: A novel scheme for demodulating frequency modulated optical signals is proposed. It uses polarization maintaining fiber Bragg grating (PM FBG) as a frequency discriminator. The basic principle and preliminary results of linearity and demodulation are presented.

title: Photonic multiple millimeter wave signal generation and distribution over reconfigurable hybrid SSMF/FSO links
abstract: Microwave photonics provides attractive solutions for millimeter wave (mmW) signal generation. In this paper, we demonstrate photonically generated multiple mmW signals transmission over a wavelength division multiplexed (WDM) hybrid optical network based on optical fiber and free space optics (FSO) links. The experimental results demonstrate the generation and reconfigurable signal distribution from a central office to base stations in the frequency range 14 40 G H z with phase noise levels below 87 d B c H z Moreover, 10 G b s data transmission has been demonstrated over photonically generated 40 G H z mmW signal. We show that FSO technology provides a possible solution for mmW fronthaul in 5th generation networks to extend the optical access network providing increased wireless accessibility and maintaining transmission capacity.

title: Novel applications of plasmonics and photonics devices to sub THz wireless
abstract: We recently demonstrated modulators based on plasmonic technology displaying a flat frequency response reaching 500 GHz, high linearity and power handling. We discuss their potential for extending microwave photonics (MWP) applications to the sub THz range, demonstrating analog photonic links with bandwidth in excess of 100 GHz and the capability of direct mm wave to optical conversion.

title: Photodiodes for Si photonics (Conference Presentation)
abstract: High speed high power photodiodes are key components in microwave photonic applications including antenna remoting, generation of microwave signals, and analog optical links. With the rapid emergence of Si photonics, it is becoming increasing important to develop approaches to incorporate these photodiodes into a Si platform. For integration of III V photodiodes on silicon, various integration approaches have been reported, including adhesive wafer bonding, direct molecular wafer bonding, and direct III V material growth on Si. This paper will report the integration of InGaAs/InGaAsP/InP modified uni traveling carrier photodiodes using each of these techniques. In addition, high power Ge on Si photodiodes will be discussed.

title: All Optical and Broadband Microwave Image Reject Receiver Based on Phase Modulation and I/Q Balanced Detection
abstract: Image reject radio frequency (RF) receiver is the backbone of modern RF systems, but often suffers from limited bandwidth, local oscillator (LO) leakage, even order distortion, and I/Q imbalance. A wideband photonic image reject RF receiver based on two phase modulators (PMs) in a Sagnac loop and an I/Q balanced detector is proposed. In the experiment, excellent I/Q amplitude balance <0.8 dB) and phase balance <0.7 degrees) over a wide operating frequency from 8 to 40 GHz are achieved. Due to balanced detection, the even order distortion and dc offset are significantly suppressed. Combined with an analog intermediate frequency (IF) quadrature coupler, the image reject RF receiver is implemented with a spurious free dynamic range (SFDR) of 99.4 dB*Hz2/3 and an image rejection of 50.3 dB. An antenna remoting RF vector signal with image interference is down converted to the IF domain. Benefiting from the significant image rejection and Sagnac loop architecture, a good constellation diagram and a low error vector magnitude (EVM) of the desired signal are obtained.

title: A general analytical method for suppressing the third order intermodulation in microwave photonic link based on dual parallel Mach Zehnder modulator
abstract: A general analytical method by adjusting the phases of the signals applied to the four electrodes of a dual parallel Mach Zehnder modulator (DPMZM) is proposed to suppress the third order intermodulation (IMD3) in microwave photonic link. Through the detailed theoretical and numerical analysis, all the signal combinations for the four electrodes of the DPMZM are found and classified into three groups according to the IMD3 cancellation mechanism. In this process, a new group of the four electrodes' setting to suppress the IMD3 is found. The simulation and experiment are carried out to verify our discovery. It is found that this newly found group can also suppress IMD3 by about 30 dB and improve the spurious free dynamic range (SFDR) by 11.5 dB Hz 2 3

title: Photonic Mixer Incorporating All Optical Microwave Frequency Generator Based on Stimulated Brillouin Scattering Using Single Laser Source
abstract: In this paper, we report the theoretical and experimental implementation of a photonic mixer for Radio Over Fiber (RoF) transmission systems, which incorporates an all optical 10.87 GHz microwave frequency signal generator based on beating laser frequency with its first order Stimulated Brillouin Scattering (SBS) frequency shift. A 13GHz Radio Frequency (RF) is down converted to 2.13 GHz Intermediate Frequency (IF) signal. The proposed system configuration represents a cost effective photonic mixer that can be deployed for up and down conversion around 11 GHz in RoF transmission systems. The optically generated microwave signal of 10.87 GHz has a phase noise of 109 dBc/Hz at 15 MHz offset. The proposed photonic mixer exhibits a Spurious Free Dynamic Range (SFDR) of 93dB.Hz 2/3. This RoF transmission system configuration deploys dual parallel Gallium Arsenide (GaAs) Mach Zehnder Modulator as a photonic mixer, and a single laser source as a Brillouin pump and as an optical carrier at the same time. To the best of our knowledge, this type of photonic mixers has not been reported in the literature.