Showing papers by "Leif Katsuo Oxenløwe published in 2015"
TL;DR: The use of a structure with broken symmetry in combination with a well-engineered Fano resonance is shown to suppress patterning effects as well as lower the energy consumption, enabling the achievement of error-free 10 Gbit/s modulation with low pump energy using realistic pseudorandom binary sequence patterns.
Abstract: We experimentally demonstrate ultrafast all-optical modulation using an ultracompact InP photonic-crystal Fano structure. In contrast to symmetric configurations previously considered, the use of a structure with broken symmetry in combination with a well-engineered Fano resonance is shown to suppress patterning effects as well as lower the energy consumption. These properties enable the achievement of error-free 10 Gbit/s modulation with low pump energy using realistic pseudorandom binary sequence patterns. At 20 Gbit/s, the bit error ratio remains well below the limit for forward error correction.
41 citations
16 Nov 2015
TL;DR: In this article, the authors demonstrate a 400 GHz carrier wireless transmission system with real-time capable detection and demonstrate transmission of a 60 Gbit/s signal derived from optical Nyquist channels in a 12.5 GHz ultra-dense wavelength division multiplexing (UD-WDM) grid and carrying QPSK modulation.
Abstract: We experimentally demonstrate a 400 GHz carrier wireless transmission system with real-time capable detection and demonstrate transmission of a 60 Gbit/s signal derived from optical Nyquist channels in a 12.5 GHz ultra-dense wavelength division multiplexing (UD-WDM) grid and carrying QPSK modulation. This is the highest data rate demonstrated for carrier frequencies above 300 GHz and also validates the feasibility of bridging between next generation 100 GbE wired data streams and indoor wireless applications.
37 citations
22 Mar 2015
TL;DR: The highest reported conversion efficiency/length/pump-power, ultra-broadband four-wave mixing, and first-ever wavelength conversion of 1.28-Tbaud serial data signals in a 3-mm long dispersion-engineered AlGaAs nano-waveguide are demonstrated.
Abstract: We present an AlGaAs-on-insulator platform for integrated nonlinear photonics. We demonstrate the highest reported conversion efficiency/length/pump-power, ultra-broadband four-wave mixing, and first-ever wavelength conversion of 1.28-Tbaud serial data signals in a 3-mm long dispersion-engineered AlGaAs nano-waveguide.
27 citations
22 Mar 2015
TL;DR: A novel PSK regenerator based on phase sensitive amplification without active phase-locking is proposed and demonstrated, applied to regenerate a phase noise degraded 10-Gbit/s DPSK signal, improving receiver sensitivity by 3.5 dB.
Abstract: We propose a scheme for phase regeneration of optical binary phase-shift keying (BPSK) data signals based on phase sensitive amplification without active phase locking. A delay interferometer is used to convert a BPSK signal impaired by noise to an amplitude modulated signal followed by cross-phase modulation in a highly nonlinear fiber (HNLF), which transfers the data modulation from the amplitude modulated signal to the phase of a locally generated carrier. By placing the HNLF in a loop, a stable phase relation is maintained relative to a set of counter propagating locally generated phase-locked pumps. As a result, active phase stabilization is avoided. A proof-of-principle experiment is carried out with a dual-pump degenerate phase sensitive amplifier, demonstrating regeneration for a 10-Gb/s non-return-to-zero differential BPSK data signal degraded by a sinusoidal phase-noise tone. Receiver sensitivity improvements of 3.5 dB are achieved at a bit error rate of 10−9. In addition, numerical simulations are performed comparing the idealized regenerator performance in the presence of sinusoidal phase modulation as well as Gaussian phase noise.
14 citations
TL;DR: In this paper, the authors demonstrate a 160-Gb/s Ethernet packet switch using an 8.6mm-long silicon nanowire for optical burst switching, based on cross phase modulation in silicon.
Abstract: We experimentally demonstrate a 160-Gb/s Ethernet packet switch using an 8.6-mm-long silicon nanowire for optical burst switching, based on cross phase modulation in silicon. One of the four packets at the bit rate of 160 Gb/s is switched by an optical control signal using a silicon based $1\times 1$ all-optical packet switch. Error free performance (BER < 1E-9) is achieved for the switched packet. The use of optical burst switching protocols could eliminate the need for optical buffering in silicon packet switch based optical burst switching, which might be desirable for high-speed interconnects within a short-reach and small-scale network, such as board-to-board interconnects, chip-to-chip interconnects, and on-chip interconnects.
14 citations
03 Dec 2015
TL;DR: In this paper, the authors proposed an all-optical WDM regeneration scheme for DPSK signals based on optical Fourier transformation and phase sensitive amplification, and demonstrated phase regeneration of a WDM signal consisting of 4×10Gbit/s phase noise degraded DPSK channels.
Abstract: We propose a novel all-optical WDM regeneration scheme for DPSK signals based on optical Fourier transformation and phase sensitive amplification. Phase regeneration of a WDM signal consisting of 4×10-Gbit/s phase noise degraded DPSK channels is demonstrated for the first time.
12 citations
05 Jul 2015
TL;DR: This paper evaluates the realistic throughput and accessible wireless range of a THz impulse radio communication link based on a uni-travelling photodiode (UTC-PD) as THz emitter and a photoconductive antenna (PCA) as Thz receiver.
Abstract: THz impulse radio technologies promise a new paradigm of fast wireless access with simplified wireless reception. However, huge loss of propagating broad bandwidth THz impulse radio signals limits THz wireless transmission distance and reduces the achievable link data rates. In this paper, we evaluate the realistic throughput and accessible wireless range of a THz impulse radio communication link based on a uni-travelling photodiode (UTC-PD) as THz emitter and a photoconductive antenna (PCA) as THz receiver. The impact of highly frequency-selective THz channel and the noise in the system are also considered.
9 citations
03 Dec 2015
TL;DR: In this paper, the first space-division-multiplexed based symmetric NG-PON2 network by efficiently transmitting 40 Gbit/s/spatial mode was reported.
Abstract: We report the first space-division-multiplexed based symmetric NG-PON2 network by efficiently transmitting 40 Gbit/s/spatial-mode. Error free transmission (BER of 10-9) is obtained for all the downstream and upstream data tributaries over 1-km 6-spatial-mode FMF without using MIMO DSP.
8 citations
TL;DR: In this article, the authors demonstrate four-wave mixing wavelength conversion in silicon-rich nitride waveguides, which are a promising alternative to silicon for nonlinear applications and reach -13.6 dB while showing no significant nonlinear loss.
Abstract: We demonstrate four-wave mixing wavelength conversion in silicon-rich nitride waveguides which are a promising alternative to silicon for nonlinear applications. The obtained conversion efficiency reaches -13.6 dB while showing no significant nonlinear loss.
8 citations
03 Dec 2015
TL;DR: Simulations show improved performance compared to all-optical fat-tree datacenter architecture with 40%-99% improved connection request blocking and 3%-17% improved resource utilization.
Abstract: Ring-based generic network architecture for all-optical datacenters is proposed, offering highly scalable interconnection network with reduced cabling complexity. Simulations show improved performance compared to all-optical fat-tree datacenter architecture with 40%–99% improved connection request blocking and 3%–17% improved resource utilization.
5 citations
10 May 2015
TL;DR: In this paper, the authors demonstrate effective carrier depletion by metal-semiconductor-metal junctions for a silicon waveguide by applying bias voltages, and a shortest carrier lifetime of only 55 ps is demonstrated.
Abstract: We demonstrate effective carrier depletion by metal-semiconductor-metal junctions for a silicon waveguide Photo-generated carriers are efficiently swept out by applying bias voltages, and a shortest carrier lifetime of only 55 ps is demonstrated
10 May 2015
TL;DR: In this paper, a record low threshold power of 7 mW at ∼1.55 μm for on-chip optical parametric oscillation using a high quality factor micro-ring-resonator in a new nonlinear photonics platform: AlGaAs-on-insulator.
Abstract: We present a record-low threshold power of 7 mW at ∼1.55 μm for on-chip optical parametric oscillation using a high quality factor micro-ring-resonator in a new nonlinear photonics platform: AlGaAs-on-insulator.
22 Mar 2015
TL;DR: An all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT is proposed with BER <; 10-9 performance for all channels.
Abstract: We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER < 10−9 performance for all channels.
22 Mar 2015
TL;DR: A 640 Gbit/s all-optical NOT gate for high-speed telecommunication on-off-keying (OOK) data signals is experimentally demonstrated using linear optical signal processing based on spectral phase-only (all-pass) optical filtering to perform the target logic NOT operation.
Abstract: We experimentally demonstrate a 640 Gbit/s all-optical NOT gate for high-speed telecommunication on-off-keying (OOK) data signals. We employ linear optical signal processing based on spectral phase-only (all-pass) optical filtering to perform the target logic NOT operation.
TL;DR: In this paper, the authors proposed a scheme for phase regeneration of an optical binary phase shift keying (BPSK) data signal using a LiNbO3 phase modulator.
Abstract: We propose a scheme for phase regeneration of an optical binary phase shift keying (BPSK) data signal using a Lithium Niobate (LiNbO3) phase modulator. The scheme is based on heterodyne detection of the BPSK data signal with a continuous wave local oscillator (CW-LO). Carrier recovery is then achieved in the electrical domain using a ×2 frequency-multiplier and a narrow-band filtering scheme. Subsequently, a superposition of the recovered carrier and the heterodyne detected data signal is used to modulate the CW-LO in a LiNbO3 phase modulator. The result is a parametric mixing process in the optical domain, leading to a phase-regenerated BPSK data signal by the coherent superposition with a phase-inverted copy. The proposed scheme constitutes a compact and stable setup, where active phase-stabilization of the electrical data- and carrier-paths can potentially be avoided. An analytical derivation of the working principle is provided, using Jacobi–Anger expansions to describe the phase-modulation. A proof-of-principle experiment is carried out, demonstrating regeneration of a 10 Gb/s NRZ-BPSK data signal degraded by a 5-GHz sinusoidal phase-noise tone. In the proof-of-principle demonstration, the decorrelated data- and LO-carriers are derived from the same CW source. A preliminary test with separate CW sources for data and LO, but without the required electrical narrow-band carrier filtering, is also included. Finally, numerical simulations of the regenerator performance in the presence of wideband phase- and amplitude-noise are performed.
01 Sep 2015
TL;DR: 1 Tbit/s/core error-free performance is achieved for connections with different granularities being switched between three network nodes interconnected with 7-core multicore fibres.
Abstract: We experimentally demonstrate network nodes that enable SDM/WDM/TDM switching. 1 Tbit/s/core error-free performance is achieved for connections with different granularities being switched between three network nodes interconnected with 7-core multicore fibres.
Patent•
09 Sep 2015
TL;DR: In this paper, an all-optical orthogonal frequency division multiplexing (OFDM) transmitter for generating an OFDM output signal is described, which comprises a first time-domain optical Fourier transform (OFT) assembly, the first OFT assembly is of a K-D-K configuration and comprises in said order a first phase modulator, a dispersive element and a second phase modulators.
Abstract: The invention relates to an all-optical orthogonal frequency division multiplexing (OFDM) transmitter for generating an OFDM output signal. The transmitter comprises a first time-domain optical Fourier transform (OFT) assembly, the first OFT assembly is of a K-D-K configuration and comprises in said order a first phase modulator, a dispersive element and a second phase modulator. The first and second phase modulators are configurable for exercising a parabolic phase modulation to substantially linearly phase chirp an optical signal so as to have a chirp rate K 1 and K 2, respectively. The dispersive element has a dispersion parameter D. The phase modulators are configurable to have nominally identical chirp rates, K 1 = K 2 = K, and the OFT assembly is further configurable such that D = 1/K. The invention further relates to methods of generating an OFDM signal.
01 Oct 2015
TL;DR: In this paper, a phase sensitive amplification of a pre-conditioned signal avoiding active phase locking was proposed to avoid active phase-locking in QPSK regenerators, which was demonstrated experimentally with error-free (BER < 10−9) performance for a 10-Gbaud QRSK signal.
Abstract: We propose a novel QPSK regenerator scheme based on phase sensitive amplification of a pre-conditioned signal avoiding active phase-locking. Signal pre-conditioning is demonstrated experimentally with error-free (BER < 10−9) performance for a 10-Gbaud QPSK signal.
Proceedings Article•
01 Jan 2015
TL;DR: In this paper, the authors demonstrate network nodes that enable SDM/WDM/TDM switching and achieve 1 Tbit/s/core error-free performance for connections with different granularities.
Abstract: We experimentally demonstrate network nodes that enable SDM/WDM/TDM switching. 1 Tbit/s/core error-free performance is achieved for connections with different granularities being switched between three network nodes interconnected with 7-core multicore fibres.
TL;DR: In this paper, the authors presented a detailed numerical comparison of two promising all-optical schemes to demultiplex orthogonal frequency division multiplexing (OFDM) signals.
Abstract: In this letter, we present the first detailed numerical comparison of two promising all-optical schemes to demultiplex orthogonal frequency-division multiplexing (OFDM) signals. The investigated schemes are the optical discrete Fourier transformation (O-DFT) and the optical spectral magnification (SM) based on time lenses. In the former scheme, cascaded delay-interferometers (DIs) are used to perform the O-DFT, with subsequent active optical gating to remove the intercarrier interference (ICI). Here, a reduced-complexity partial O-DFT, realized by replacing a number of DIs with optical bandpass filters, is investigated. In the latter scheme, the OFDM spectrum is magnified, allowing for simple optical bandpass filtering of the individual subcarriers with reduced ICI. Ideally, only a single unit consisting of two time lenses is needed, reducing the complexity and potentially the energy consumption compared with the type of O-DFT scheme relying on many active gates. The bit-error-rate is estimated down to $\sim 10^{\mathrm {\mathbf {-6}}}$ by Monte Carlo bit-error counting for a 32-subcarrier OFDM input signal, showing that a performance close to the ideal O-DFT is achievable for both the reduced-complexity O-DFT and the SM scheme.
16 Nov 2015
TL;DR: In this article, the authors demonstrate 20 Gbit/s all-optical switching with low energy consumption using a simple and ultra-compact InP photonic-crystal structure by employing a well-engineered Fano resonance in combination with broken mirror symmetry.
Abstract: We experimentally demonstrate 20 Gbit/s all-optical switching with low-energy consumption using a simple and ultra-compact InP photonic-crystal structure by employing a well-engineered Fano resonance in combination with broken mirror symmetry.
05 Jul 2015
TL;DR: In this article, the capacity of optical networks while having the objective of lowering the total consumed energy per bit is challenging. But, by exploiting several dimensions, i.e., wavelength, space, time, polarisation and multilevel modulation simultaneously, a single laser can offer formidable capacity performance with potentially reduced energy consumption per bit.
Abstract: Increasing the capacity of optical networks while have the objective of lowering the total consumed energy per bit is challenging. By exploiting several dimensions, i.e. wavelength, space, time, polarisation and multilevel modulation simultaneously, a single laser can offer formidable capacity performance with potentially reduced energy consumption per bit. Up to 43 Tbit/s has been demonstrated.
12 Nov 2015
TL;DR: A detailed investigation of a double-time-lens subsystem for spectral compression of OFDM symbols and derive optimized parameter settings by simulations and experimental characterization is presented.
Abstract: We present a detailed investigation of a double-time-lens subsystem for spectral compression of OFDM symbols. We derive optimized parameter settings by simulations and experimental characterization. The required chirp for OFDM spectral compression is very large.
01 Jan 2015
TL;DR: This chapter finds that optical signal processing, where the processing is broadband and capable of handling many bits in a single operation allows for sharing the processing energy by the many bits, and hence the energy per bit is reduced.
Abstract: This chapter describes advanced functionalities for optical signal processing using optical time lenses. A special focus is devoted to functionalities that allow for energy-savings. In particular, we find that optical signal processing, where the processing is broadband and capable of handling many bits in a single operation allows for sharing the processing energy by the many bits, and hence the energy per bit is reduced. Such functionalities include serial-to-parallel conversion in a single time lens, where a large number of parallel demultiplexers may be substituted by a single time lens. Combining time lenses into telescopic arrangements allows for more advanced signal processing, such as temporal or spectral compression or magnification. A spectral telescope may for instance allow for conversion of OFDM signals to DWDM-like signals, which can be separated passively, i.e. without additional energy. This is opposed to the DFT OFDM receivers otherwise suggested, where a temporal active gate is required for each tributary. With the spectral telescope, only two active time lenses are required, irrespective of how many tributaries are used. This chapter describes how optical time lenses function and by showing examples of some advanced functionalities points to future scenarios where energy consumption may be considerably reduced.
01 Oct 2015
TL;DR: The first detailed numerical comparison of two promising all-optical schemes to demultiplex orthogonal frequency-division multiplexing (OFDM) signals is presented, showing that a performance close to the ideal O-DFT is achievable for both the reduced-complexity O- DFT and the SM scheme.
Abstract: In this paper we present the first detailed numerical comparison of two promising all-optical schemes to demultiplex orthogonal frequency-division multiplexing (OFDM) signals. The investigated schemes are the optical discrete Fourier transformation (O-DFT) and the optical spectral magnification (SM) based on time lenses. In the former scheme, cascaded delay-interferometers (DIs) are used to perform the O-DFT, with subsequent active optical gating to remove the intercarrier interference (ICI). Here a reduced-complexity partial O-DFT, realized by replacing a number of DIs with optical bandpass filters, is investigated. In the latter scheme the OFDM spectrum is magnified, allowing for simple optical bandpass filtering of the individual subcarriers with reduced ICI. Ideally only a single unit consisting of two time lenses is needed, reducing the complexity and potentially the energy consumption compared to the type of O-DFT scheme relying on many active gates. The bit-error-rate is estimated down to ∼10−6 by Monte Carlo bit-error counting for a 32-subcarrier OFDM input signal, showing that a performance close to the ideal O-DFT is achievable for both the reduced-complexity O-DFT and the SM scheme.
26 Oct 2015
TL;DR: In this article, an approach for electrical modulation of low-loss silicon nitride waveguides is proposed, using a silicon-nide waveguide evunescently loaded with a thin silicon slab.
Abstract: An approach for electrical modulation of low-loss silicon nitride waveguides is proposed, using a silicon nitride waveguide evunescently loaded with a thin silicon slab. The thermooptic phase-shift characteristics are investigated in a racetrack resonator configuration.
05 Jul 2015
TL;DR: This talk will present the work of the EU project COSIGN targeting the development of optical data plane solutions for future high-capacity datacenter networks (DCNs) with high capacity and high flexibility through software control.
Abstract: This talk will present the work of the EU project COSIGN targeting the development of optical data plane solutions for future high-capacity datacenter networks (DCNs). Optical data planes with high capacity and high flexibility through software control are developed in order to enable a coherent management and orchestration of all resources in the datacenter including the datacenter network.
12 Nov 2015
TL;DR: A 15 dB bandwidth of 1 THz confirms that this THz impulse system has a great potential of supporting ultrafast data rates, eventually for Terabit wireless communication era.
Abstract: We experimentally characterize a ultrabroadband terahertz (THz) impulse radio system with up to 10 GHz repetition rate. THz generation and radiation are realized in an antenna-integrated uni-traveling-carrier photodiode (UTC-PD), and THz reception is implemented based on photoconductive sampling by using a photoconductive antenna (PCA). We analyze the performance in terms of bandwidth and the features of the THz pulses. A 15 dB bandwidth of 1 THz confirms that this THz impulse system has a great potential of supporting ultrafast data rates, eventually for Terabit wireless communication era.
03 Dec 2015
TL;DR: In this article, the advantages and limitations of using silicon nanowires for optical signal processing are revealed through experimental demonstrations of various optical signals processing systems at DTU Fotonik.
Abstract: In this paper, we present recent research on silicon nanowires for ultra-fast and ultra-broadband optical signal processing at DTU Fotonik. The advantages and limitations of using silicon nanowires for optical signal processing are revealed through experimental demonstrations of various optical signal processing.
01 Jan 2015
TL;DR: This PhD thesis aims at investigating the possibility of designing energy-efficient high-capacity (up to Tbit/s) optical network scenarios, leveraging on the effect of collective switching of many bits simultaneously, as is inherent in high bit rate serial optical data signals.
Abstract: (17/02/2019) OTDM Networking for Short Range High-Capacity Highly Dynamic Networks This PhD thesis aims at investigating the possibility of designing energy-efficient high-capacity (up to Tbit/s) optical network scenarios, leveraging on the effect of collective switching of many bits simultaneously, as is inherent in high bit rate serial optical data signals. The focus is on short range highly dynamic networks, catering to data center needs. The investigation concerns optical network scenarios, and experimental implementations of high bit rate serial data packet generation and reception, scalable optical packet labeling, simple optical label extraction and stable ultra-fast optical packet switching, with the constraint that there must be potential energy savings, which is also evaluated. A survey of the current trends in data centers is given and state-of-the-art research approaches are mentioned. Optical time-division multiplexing is proposed and demonstrated to generate Tbit/s data packets, and time lens based serial-to-parallel converter is employed to demultiplex each high-capacity packet into lower bit rate tributaries. A novel optical label scheme is suggested and experimentally demonstrated, where the label information is inserted in-band in the broad signal spectrum and its scalability is demonstrated by generating up to 65.536 distinct optical labels for 1.28 Tbit/s data packets. The optical label information is extracted and decoded using a simple opto-electronic based label detection module. In particular, four stable switching control signals are decoded from 640 Gbit/s variable length data packets. Finally, three optical switching scenarios of high-capacity data packets, including a record-high 1×2 optical packet switching of 1.28 Tbit/s serial packets, are experimentally demonstrated using electro-optic based LiNbO3 switches.