A5048810929- Photonic and Optical Devices
- Optical Network Technologies
- Advanced Fiber Laser Technologies
- Advanced Photonic Communication Systems
- Microwave Engineering and Waveguides
- Microwave and Dielectric Measurement Techniques
- Radio Frequency Integrated Circuit Design
- Semiconductor Lasers and Optical Devices
- Advancements in PLL and VCO Technologies
- Advanced Optical Network Technologies
- Advanced Antenna and Metasurface Technologies
- Advanced Fiber Optic Sensors
- Antenna Design and Analysis
- Mechanical and Optical Resonators
- Silicon Nanostructures and Photoluminescence
- Analytical Chemistry and Sensors
- Semiconductor Quantum Structures and Devices
- PAPR reduction in OFDM
- Ultra-Wideband Communications Technology
- Advanced Frequency and Time Standards
- Acoustic Wave Resonator Technologies
- Photonic Crystals and Applications
RWTH Aachen University
2015-2024
Westfälische Hochschule
2016-2018
Jülich Aachen Research Alliance
2015
Universidad de Málaga
2009-2014
European Telecommunications Standards Institute
2014
We report on the design of Silicon Mach-Zehnder carrier depletion modulators relying epitaxially grown vertical junction diodes. Unprecedented spatial control over doping profiles resulting from combining local ion implantation with epitaxial overgrowth enables highly linear phase shifters high modulation efficiency and comparatively low insertion losses. A average shifter VπL = 0.74 V⋅cm is reached between 0 V 2 reverse bias, while maintaining optical losses at 4.2 dB/mm intrinsic RC cutoff...
Abstract We demonstrate a wavelength domain-multiplexed (WDM) optical link relying on single section semiconductor mode-locked laser (SS-MLL) with quantum dash (Q-Dash) gain material to generate 25 carriers spaced by 60.8 GHz, as well silicon photonics (SiP) resonant ring modulators (RRMs) modulate individual channels. The requires reamplification provided an erbium-doped fiber amplifier (EDFA) in the system experiments reported here. Open eye diagrams signal quality factors (Q-factors)...
We demonstrate an integrated 8 by 14 Gbps dense wavelength division multiplexed silicon photonics transceiver that makes use of external mode-locked laser as a light source and single semiconductor optical amplifier for post-modulation signal amplification. Remaining components necessary modulation, filtering (de‑)multiplexing are monolithically in chip. In all system experiments, eight channels jointly operated with independent data streams order to include impairments arising out nonlinear...
We present a novel resonant Mach-Zehnder modulator whose arms are each loaded with five identical resonators. Size and power consumption aggressively reduced compared to conventional modulators based on linear phase shifters. At the same time, large optical bandwidth of 3.8 nm is maintained. experimentally demonstrate open eye diagrams at 30 Gbps signal Q-factor remaining within factor 2 its peak value in an operational temperature range spanning 55°C.
A coherent receiver based on a 120° downconverter architecture, inherited from previous approaches at the microwave and optical fields, is proposed, analyzed, numerically evaluated compared to conventional 90° alternative. It shown that, due its superior calibration procedure, new architecture allows full compensation of imbalances in front-end thus leading an extended dynamic range broader operating bandwidth than counterpart. Simulation results monolithically integrated downconverters show...
We demonstrate a silicon photonic transmitter for soliton-based communications enabling the interleaving of QPSK and APSK modulated soliton pulses overlapping in both time frequency domains. The nonlinear Fourier transform is used to determine adequate launch conditions facilitate equalization at receiver. A spectral efficiency 0.5 b/s/Hz per polarization reached over 5400 km transmission distance constitutes, best our knowledge, record such long distances. Linear minimum mean square error...
We present a three-section quadrature hybrid based on slot-coupled directional couplers, which operates over bandwidth from 3.1 to 10.6 GHz. A prototype has been fabricated exhibits return loss better than 20 dB, isolation around an amplitude imbalance between output ports of less plusmn0.75 dB and phase +1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">deg</sup> -3 across the 3.1-10.6 GHz band. This design outperforms previously reported...
We derive compact equations describing the modification of amplified spontaneous emission signal beat noise arising from optical and electrical filtering in optically preamplified direct detection receivers. In particular, we show that this typically results a further decrease quality factor. This is particularly pronounced presence filters with steep transfer functions such as, e.g., occurring when feeding through an antialiasing filter prior to analog-to-digital conversion or real-time...
We present a flip-chip integration process in which the vertical alignment is guaranteed by mechanical contact between pedestals defined recess etched into silicon photonics chip and laser or semiconductor optical amplifier. By selectively etching up to active region of III-V materials, we can make accuracy independent on control applied layer thicknesses during fabrication, enabling tolerances below ±10 nm (Z-)direction.
We demonstrate a complete Silicon Photonics WDM link relying on single section semiconductor mode-locked laser and SOA to support up 12 multiplexed channels with bit error rate of 1e-12 at serial data rates 14 Gbps without channel pre-emphasis, equalization or forward correction. Individual reach free operation 25 multi-channel is shown be compatible standard 7% overhead hard decision transmitter receiver chips are hybridly integrated driver electronics. A detailed model derived verified....
Since its introduction in 1994 direct conversion sixport receivers have attracted a considerable attention at microwave frequencies, with most recent work focusing on the so called analog I/Q generation. Besides applications six-port regeneration play crucial role optical communications field, as they are promising candidates for coherent that being developed 100 Gigabit Ethernet transceivers. In this paper we analytically model influence of junction hardware impairments receiver...
This paper presents a six-section multi-layer asymmetric 10 dB directional coupler based on offset broadside coupled striplines, using Low Temperature Co-fired Ceramic (LTCC) technology, which operates over decade bandwidth from 1.8 to 18 GHz.It features high performance transitions between the external signal layer and buried layers, as well novel mixed first section solve limitations of access bends.A prototype was manufactured that exhibits return loss better than 15 dB, isolation 23...
We present wideband and large free spectral range optical filters with steep passband edges for the selection of adjacent WDM communication channels that can be reliably fabricated mainstream silicon photonics technology. The devices are based on three cascaded stages coupled resonator waveguides loaded a common bus waveguide. These differ in number resonators but implemented exactly identical unit cells, comprised matched racetrack layout uniform spacing between cells. different each stage...
We present a multilayer 4 × Butler matrix based on corrugated slot-coupled structures, which operates over the complete UWB band (3.1 to 10.6 GHz) with excellent phase and amplitude performance. A prototype has been fabricated covers measured return loss better than 21 dB, an isolation 24 imbalance lower 1.2 dB maximum differential error of ±4.5°.
Electrical-optical signal processing has been shown to be a promising path overcome the limitations of state-of-theart all-electrical data converters. In addition ultra-broadband processing, it allows leveraging ultra-low jitter mode-locked lasers and thus increasing aperture limited effective number bits at high analog frequencies. this paper, we review our recent progress towards optically enabled time-and frequency-interleaved analog-to-digital converters, as well their monolithic...
In this paper a robust technique for the design of high performance directional couplers is proposed.It combines advantages wiggly coupled lines and slot-coupled but overcomes their main limitations.The key to novel new corrugated slot that allows perfect compensation even odd mode phase velocities can be easily designed using Bloch-Floquet theory, yielding outstanding performance.To demonstrate validity proposed technique, two different wideband presented.The first consists 10 dB asymmetric...
In this work we propose the utilization of Butler matrix as a six-port I/Q demodulator. The inherent symmetry its topology allows to overcome intrinsic amplitude and phase imbalances traditional approaches making it more suitable for design high performance networks. To demonstrate validity proposal has been designed covering complete UWB band results are compared with approaches.
Driving electro-optic modulators in lumped-element (LE) configuration allows for small footprint, reduced power consumption, and improved high-speed performance. The main shortcoming of conventional rectilinear LE are the required high drive-voltages, resulting from their shortened phase-shifters. To address this, we introduce a Mach- Zehnder modulator with meandered phase shifters (M-MZM), which can be driven configuration, while keeping optical shifter length same order as traveling-wave...
In this paper, a novel frequency-locked loop (FLL) architecture for phase-noise reduction of wideband voltage-controlled oscillators (VCO) is presented. The circuit makes use phase-shifterless frequency discriminator, which completely avoids the any control circuitry to keep in its quadrature condition, highly simplifying loop. FLL circuit, can be operated transparent way, easily interchangeable with original VCO. An prototype, based on commercial state-of-the-art VCO, has been fabricated...
Based on the single channel characterization of a Silicon Photonics (SiP) transceiver with Semiconductor Optical Amplifier (SOA) and semiconductor Mode-Locked Laser (MLL), we evaluate optical power budget corresponding Wavelength Division Multiplexed (WDM) link in which penalties associated to multi-channel operation management polarization diversity are introduced. In particular, cross-talk as well Cross Gain Modulation (XGM) Four Wave Mixing (FWM) inside SOA taken into account. these...
We present the concept and design of a 100 GHz PIC-based nonlinear frequency division multiplexed transmission system in which four b-modulated spectrally overlapping channels are stitched without guard bands to obtain continuous spectrum. Neural network-based equalizers used at receiver for improved performance. Simulations show that proposed alleviates problem interaction between neighboring channels, would, otherwise, be out reach even neural network equalization solve on its own. The...
We demonstrate an O-band resonantly enhanced Mach-Zehnder modulator utilizing highly overcoupled resonators with staggered resonance wavelengths that achieves operating range of 6.6 nm (7.1 nm) a 1 dB (3 dB) optical modulation amplitude penalty. It can be operated in power-efficient lumped-element configuration without any tuning the extended temperature 80°C.
A frequency locked loop (FLL) for phase noise reduction of wideband voltage controlled oscillators is proposed. The key building block the system a low (−160 dBV/Hz) and high sensitivity (22 V/GHz) delay line discriminator with 5–8 GHz coverage, which makes use performance multilayer hybrid. authors derive closed‐form, universal design equations maximum stability FLL circuitry. Application proposed technique to state‐of‐the‐art oscillator operating in band yields 8–10 dB at 100 kHz 5 1 MHz...
We report on the monolithic integration of a new class reflown silica microtoroid resonators with silicon nanowaveguides fabricated top film.Connectivity other photonics devices is enabled by inversion toroid geometry, defined etching circular opening rather than disk in an undercut membrane.Intrinsic quality factors up to 2 million are achieved and several avenues process improvement identified that can help attain higher (> 10 8 ) possible microtoroids.Moreover, due being formed standard...