Microring Resonator Modulators Research Articles

Universal all-optical zero-bias logic gates in silicon photonics.

Universal all-optical (optical input - optical output) logic gates, realized in a commercial foundry silicon photonics process, are reported. Microring resonator modulator and zero-biased stacked photodiodes are used to create the required optical input-output nonlinear transfer function for optical gate realizations. Several logic gate functions, specifically NOR which is a universal logic gate that can be used to implement any logic, are demonstrated. Logic operation on 10 Mbps data streams is demonstrated using universal optical logic gates without requiring any electrical supply voltage. The total optical power required for one such universal logic gate is 160 µW.

Silicon microring resonator modulator based on PIN junction: performance optimization

Silicon microring resonator modulator based on PIN junction: performance optimization

LiNbO3-Based Synaptic Sensors via Microring Resonator Modulators

LiNbO₃-Based Synaptic Sensors via Microring Resonator Modulators

Silicon Integrated Microwave Photonic Mixer Based on Cascaded Microring Resonator Modulators

Silicon Integrated Microwave Photonic Mixer Based on Cascaded Microring Resonator Modulators

A 5 × 200 Gbps microring modulator silicon chip empowered by two-segment Z-shape junctions

Optical interconnects have been recognized as the most promising solution to accelerate data transmission in the artificial intelligence era. Benefiting from their cost-effectiveness, compact dimensions, and wavelength multiplexing capability, silicon microring resonator modulators emerge as a compelling and scalable means for optical modulation. However, the inherent trade-off between bandwidth and modulation efficiency hinders the device performance. Here we demonstrate a dense wavelength division multiplexing microring modulator array on a silicon chip with a full data rate of 1 Tb/s. By harnessing the two individual p-n junctions with an optimized Z-shape doping profile, the inherent trade-off of silicon depletion-mode modulators is greatly mitigated, allowing for higher-speed modulation with energy consumption of sub-ten fJ/bit. This state-of-the-art demonstration shows that all-silicon modulators can practically enable future 200 Gb/s/lane optical interconnects.

Enhanced Pockels Effect in AlN Microring Resonator Modulators Based on AlGaN/AlN Multiple Quantum Wells

Enhanced Pockels Effect in AlN Microring Resonator Modulators Based on AlGaN/AlN Multiple Quantum Wells

Design of Ultra-Compact and Highly-Sensitive Graphene Assisted Silicon Micro-Ring Resonator Modulator for Switching Applications

Design of Ultra-Compact and Highly-Sensitive Graphene Assisted Silicon Micro-Ring Resonator Modulator for Switching Applications

Design Considerations for Energy Efficient DWDM PAM4 Transceivers Employing Avalanche Photodiodes

AbstractAn effective approach to increase per‐fiber bandwidth is to combine per‐wavelength four‐level pulse amplitude modulation (PAM4) with dense wavelength division multiplexing (DWDM). Silicon photonic transceivers based on microring resonator modulators and drop filters can allow for an efficient realization of this. Utilizing avalanche photodiodes (APDs) in the receiver front‐ends of these transceivers can significantly improve sensitivity, allowing for reduced source laser power and overall improved power efficiency. This paper analyzes the optical‐modulation amplitude (OMA) sensitivity of these APD‐based PAM4 receivers in a silicon photonic DWDM link. A comprehensive link budget is considered that takes into account various system losses and relevant noise sources. Modeling with a developed APD that has a maximum 230 GHz gain‐bandwidth product predicts sensitivity improvements at 32 to 64 Gb s−1 PAM4 ranging from 9.8 to 12 dB relative to a conventional p‐i‐n photodiode. Scaling the APD gain‐bandwidth to 310 GHz allows support of 112 Gb s−1 with −13.2 dBm OMA sensitivity at a BER of with an APD gain of 10. Utilizing the presented architecture, link budget analysis predicts a 9.5x reduction in laser power with APDs and that 38 mW source laser optical power can support a four‐channel DWDM link operating at an aggregate 448 Gb s−1 data rate.

High-speed performance of a TDFA-band micro-ring resonator modulator and detector.

We demonstrate a silicon-on-insulator micro-ring resonator (MRR) modulator and defect-mediated (DM) detector operating at a wavelength near 2 µm for use in the thulium doped fiber amplifier wavelength band. The MRR modulator was critically coupled with an unbiased notch-depth of 20 dB and Q-factor of 4700. The resonance shift under reverse bias was 23 pm/V with a calculated VπLπ of 2.2 to 2.6 V·cm from -1 to -8 V, respectively. Simulations are in good agreement with the measured data. The experimental modulation bandwidth was 12.5 GHz, limited by the response of the commercial external detector used for this measurement. The DM detector was operated in avalanche mode, had 1.97 µm wavelength responsivities of 0.04 and 0.14 A/W, and had bandwidths greater than 16 and 7.5 GHz at -15 and -30 V biases, respectively. Large-signal measurement demonstrated open eye-diagrams at 5, 10, and 12.5 Gbps for the DM detector and also for an optical link consisting of the modulator and detector integrated on the same silicon chip.

Enhanced NRZ multi-carriers modulation technologies for microresonators in THz technology applications

Abstract Multi-optical carriers suitable for use in an optical communication system have been generated via integrated microring resonators. These carriers were sufficiently stable for travel in either a free space channel or waveguides while experiencing very low dispersion. Multiple carriers were created using the integrated microring resonators, with each carrier possessing a frequency at 193.012, 193.086, 193.186 and 193.268 terahertz (THz). The second part which is the non-return-to-zero (NRZ) modulation has been performed using the microring resonator modulators. The objective of the research is to generate multi-carriers at infrared region and modulate them for the optical communication application using the microring resonators. At the transmitter part, series of microring resonators have been used to generate four different THz frequencies which can be either de-multiplexed and modulated individually using the NRZ modulation format or modulated without de-multiplexing them as these enter a series of microring resonator modulators and microring resonator drop filters. As results, the detection of the four NRZ modulated frequencies has been performed successfully with high signal qualities. Therefore, in this research microring resonators are used for different purposes as to generate optical signals (at the transmitter part), modulate and filter them along an optical transmission link.

Ultrafast physical random bit generation from a chaotic oscillator with a silicon modulator.

We demonstrate physical random bit (PRB) generation from two chaotic optoelectronic oscillators (OEOs) with silicon Mach-Zehnder and microring resonator modulators. The carrier-injection modulation and the beam interference provide the nonlinearity for the OEO. We digitalize the chaotic waveforms from the two OEOs at 40GS/s with 8-bit resolution and use self-delay bitwise exclusive-or operation as a post-processing method. The randomness of the resulting 320Gbps PRB sequences is verified by the National Institute of Standards and Technology Special Publication 800-22 statistical tests. With the progress of silicon photonic circuits, there is a potential to fabricate a monolithic chaotic OEO chip for compact PRB generation.

Optimal design of a microring cavity optical modulator for efficient RF-to-optical conversion.

The efficiency of optical sideband generation with a microring resonator modulator as a function of modulator parameters is studied taking into account the photon dynamics inside the resonator. The best achievable modulation efficiency is determined for any choice of the resonator intrinsic quality factor, and analytic solutions for the optimum modulator parameters, namely the coupling coefficient and the detuning between the frequencies of the input laser light and the microring resonance, are provided. This analysis is carried out both for a narrowband RF signal, in which case the modulator is optimized for the center frequency of this signal, and for wideband signals, when high conversion efficiency over a wide range of RF frequencies is desired. The obtained results are expected to be useful coherent optical links, direct detection RF receivers, and optical wavelength converters.

Resonance control of a silicon micro-ring resonator modulator under high-speed operation using the intrinsic defect-mediated photocurrent.

A method to stabilize the resonance wavelength of a depletion-type silicon micro-ring resonator modulator during high-speed operation is described. The method utilizes the intrinsic defect-mediated photo-absorption of a silicon waveguide and results in a modulator chip fabrication process that is free of heterogeneous integration (for example using germanium), thus significantly reducing the complexity and cost of manufacture. Residual defects, present after p-n junction formation, are found to produce an adequate photocurrent for use as a feedback signal, while an integrated heater is used to compensate for thermal drift via closed-loop control. The photocurrent is measured by a source-meter, which simultaneously provides a DC bias to the integrated heater during high-speed operation. A drop-port or an integrated extrinsic detector is not needed. This feedback control method is experimentally demonstrated via a computer-aided proportional-integral-differential loop. The resonance locking is validated for 12.5 Gb/s intensity modulation in a back-to-back bit-error-rate measurement. The stabilization method described is not limited to a specific modulator design and is compatible with speeds greatly in excess of 12.5 Gb/s, in contrast to the bandwidth limitation of other stabilization methods that rely on intrinsic photo-carrier generation through non-linear processes such as two-photon-absorption. Further, the use of intrinsic defects present after standard fabrication insures that no excess loss is associated with this stabilization method.

Silicon-photonic PTAT temperature sensor for micro-ring resonator thermal stabilization.

We present a scheme for thermal stabilization of micro-ring resonator modulators through direct measurement of ring temperature using a monolithic PTAT temperature sensor. The measured temperature is used in a feedback loop to adjust the thermal tuner of the ring. The closed-loop feedback system is demonstrated to operate in presence of thermal perturbations at 20Gb/s.

Modeling and bandwidth optimization of microring resonator modulators with phase ring enhancements

The modeling of microring resonator modulators with phase rings is presented. The phase ring effect and the bandwidth optimization are studied by using the proposed model. Results show that the phase ring can enhance the modulation effectively. It also causes modulation resonances which worsens the modulation performances. Resonators with double phase rings keep the coupling region symmetric and have good phase enhancement ability. The amplitude of the modulated signal can be increased substantially while the phase rings are optimized by setting the operating point at the resonance point.

Small-signal analysis of microring resonator modulators

We derive the frequency-dependent modulation transfer functions for microring resonator modulators, using a small-signal analysis. Modulation efficiencies are obtained in terms of familiar optical cavity parameters, which provide an intuitive understanding of device performance. The results are in good agreement with experimental data, and are used to compare operating characteristics between resonance-modulated and coupling-modulated microresonators.

基于硅基微环的光双二进制

A silicon-based microring modulator and a narrow-band optical Gaussian filter were employed to generate optical duobinary at 10Gbit/s.Performance of the optical duobinary signal was analyzed in terms of laser linewidth,laser operating wavelength,fiber length,and filter bandwidth using Optisystem and Matlab.Simulation results show the optical duobinary signal is sensitive to laser linewidth and wavelength.At the BER of 10-9,the maximum transmission distance of the optical duobinary format can be up to 60km with the optimal Gaussian filter bandwidth of 8GHz.

Opportunities and Challenges of Using Plasmonic Components in Nanophotonic Architectures

Nanophotonic architectures have recently been proposed as a path to providing low latency, high bandwidth network-on-chips. These proposals have primarily been based on micro-ring resonator modulators which, while capable of operating at tremendous speed, are known to have both a high manufacturing induced variability and a high degree of temperature dependence. The most common solution to these two problems is to introduce small heaters to control the temperature of the ring directly, which can significantly reduce overall power efficiency. In this paper, we introduce plasmonics as a complementary technology. While plasmonic devices have several important advantages, they come with their own new set of restrictions, including propagation loss and lack of wave division multiplexing (WDM) support. To overcome these challenges we propose a new hybrid photonic/plasmonic channel that can support WDM through the use of photonic micro-ring resonators as variation tolerant passive filters. Our aim is to exploit the best of both technologies: wave-guiding of photonics, and modulating using plasmonics. This channel provides moderate bandwidth with distance independent power consumption and a higher degree of temperature and process variation tolerance. We describe the state of plasmonics research, present architecturally-useful models of many of the most important devices, explore new ways in which the limitations of the technology can most readily be minimized, and quantify the applicability of these novel hybrid schemes across a variety of interconnect strategies. Our link-level analysis shows that the hybrid channel can save from 28% to 45% of total channel energy-cost per bit depending on process variation conditions.

A Monolithic 25-Gb/s Transceiver With Photonic Ring Modulators and Ge Detectors in a 130-nm CMOS SOI Process

A fully-integrated, silicon photonic transceiver is demonstrated in a silicon-on-insulator process using photonic microring resonator modulators for low power consumption. The trade-offs between bandwidth and extinction ratio are discussed and motivate the use of transmit pre-emphasis for ring modulators to increase the interconnect data rate. The transmitter and receiver is demonstrated to data rates of 25 Gb/s with a BER of 10 ^-12. The total power consumption of the transceiver is 256 mW and demonstrates a link efficiency of 10.2 pJ/bit excluding laser power. At 25 Gb/s, the driver operates at 7.2 pJ/bit.

Modeling and Analysis of Microring Resonator Modulators With Feedback Waveguide Coupling

The model and dynamic numerical solution of microring resonator modulators with feedback waveguide coupling are proposed and used to analyze the modulation performance. The sinusoidal intensity modulation output and bandwidth are presented. The feedback arm modulation manner is potential to ensure stable output with frequency increasing and wide bandwidth. Phase characteristics studies show that the resonator is suitable for phase shift keying. Furthermore, the Gaussian pulse modulation is studied. Results show that linear and undistorted output can be achieved for narrow and high speed pulse modulation while the resonator is biased at critical coupling position.