Iosif Demirtzioglou

Fibre-optic metadevice for all-optical signal modulation based on coherent absorption

Recently, coherent control of the optical response of thin films in standing waves has attracted considerable attention, ranging from applications in excitation-selective spectroscopy and nonlinear optics to all-optical image processing. Here, we show that integration of metamaterial and optical fibre technologies allows the use of coherently controlled absorption in a fully fiberized and packaged switching metadevice. With this metadevice, which controls light with light in a nanoscale plasmonic metamaterial film on an optical fibre tip, we provide proof-of-principle demonstrations of logical functions XOR, NOT and AND that are performed within a coherent fibre network at wavelengths between 1530 and 1565 nm. The metadevice has been tested at up to 40 gigabits per second and sub-milliwatt power levels. Since coherent absorption can operate at the single-photon level and with 100 THz bandwidth, we argue that the demonstrated all-optical switch concept has potential applications in coherent and quantum information networks.Here, the authors show that integration of metamaterial and optical fibre technologies enables all-optical XOR, NOT and AND logical functions that are performed at up to 40 gigabits per second with few femtojoules per bit energy consumption within a coherent fully fiberized network.

Frequency comb generation in a silicon ring resonator modulator

We report on the generation of an optical comb of highly uniform in power frequency lines (variation less than 0.7 dB) using a silicon ring resonator modulator. A characterization involving the measurement of the complex transfer function of the ring is presented and five frequency tones with a 10-GHz spacing are produced using a dual-frequency electrical input at 10 and 20 GHz. A comb shape comparison is conducted for different modulator bias voltages, indicating optimum operation at a small forward-bias voltage. A time-domain measurement confirmed that the comb signal was highly coherent, forming 20.3-ps-long pulses.

Picosecond all-optical switching and dark pulse generation in a fibre-optic network using a plasmonic metamaterial absorber

Coherent interaction of two light waves on a film of subwavelength thickness provides remarkable opportunities for controlling intensity and polarization of light beams as well as all-optical image processing. Here, we show that such interactions can be used for optical dark pulse generation and basic all-optical signal processing in fully fiberized coherent information networks with 1 THz bandwidth. With an encapsulated plasmonic metamaterial absorber operating in the telecommunications C-band, we demonstrate switching and dark pulse generation with 1 ps laser pulses.Coherent interaction of two light waves on a film of subwavelength thickness provides remarkable opportunities for controlling intensity and polarization of light beams as well as all-optical image processing. Here, we show that such interactions can be used for optical dark pulse generation and basic all-optical signal processing in fully fiberized coherent information networks with 1 THz bandwidth. With an encapsulated plasmonic metamaterial absorber operating in the telecommunications C-band, we demonstrate switching and dark pulse generation with 1 ps laser pulses.

Dissipative optical switch for coherent fibre networks with 100 THz bandwidth

We provide the first demonstration of a high-bandwidth, low-intensity fiberized all-optical gate exploiting coherent absorption in a plasmonic metamaterial film. The fully packaged fiberized version of the switch has been tested to the bandwidth of 1 GHz while free-space versions of the gate have been shown to provide 100 THz bandwidth and to operate at arbitrarily low intensities. Our work illustrates how major bandwidth and energy challenges of optical telecommunications and information processing networks can be tackled by merging metamaterials and optical fibre technologies.

Silicon Photonic Modulators for High Speed Optical Links

We discuss recent progress on the design of silicon photonic modulators for high speed digital and analog optical links and their implementation using advanced modulation formats (including PAM and DMT).

49.6 Gb/s direct detection DMT transmission over 40 km single mode fibre using an electrically packaged silicon photonic modulator

We present the characterization of a silicon Mach-Zehnder modulator with electrical packaging and show that it exhibits a large third-order intermodulation spurious-free dynamic range (> 100 dB Hz2/3). This characteristic renders the modulator particularly suitable for the generation of high spectral efficiency discrete multi-tone signals and we experimentally demonstrate a single-channel, direct detection transmission system operating at 49.6 Gb/s, exhibiting a baseband spectral efficiency of 5 b/s/Hz. Successful transmission is demonstrated over various lengths of single mode fibre up to 40 km, without the need of any amplification or dispersion compensation.

Experimental comparison of direct detection Nyquist SSB transmission based on silicon dual-drive and IQ Mach-Zehnder modulators with electrical packaging

We have designed and fabricated a silicon photonic in-phase-quadrature (IQ) modulator based on a nested dual-drive Mach-Zehnder structure incorporating electrical packaging. We have assessed its use for generating Nyquist-shaped single sideband (SSB) signals by operating it either as an IQ Mach-Zehnder modulator (IQ-MZM) or using just a single branch of the dual-drive Mach-Zehnder modulator (DD-MZM). The impact of electrical packaging on the modulator bandwidth is also analyzed. We demonstrate 40 Gb/s (10Gbaud) 16-ary quadrature amplitude modulation (16-QAM) Nyquist-shaped SSB transmission over 160 km standard single mode fiber (SSMF). Without using any chromatic dispersion compensation, the bit error rates (BERs) of 5.4 × 10-4 and 9.0 × 10-5 were measured for the DD-MZM and IQ-MZM, respectively, far below the 7% hard-decision forward error correction threshold. The performance difference between IQ-MZM and DD-MZM is most likely due to the non-ideal electrical packaging. Our work is the first experimental comparison between silicon IQ-MZM and silicon DD-MZM in generating SSB signals. We also demonstrate 50 Gb/s (12.5Gbaud) 16-QAM Nyquist-shaped SSB transmission over 320 km SSMF with a BER of 2.7 × 10-3. Both the silicon IQ-MZM and the DD-MZM show potential for optical transmission at metro scale and for data center interconnection.

FWM 16 QAM wavelength conversion

Dataset supports: Demirtzioglou, Iosif et al (2016) Wavelength Conversion of 16-QAM Signals in a Si- Rib Waveguide. In, European Optical Society Annual Meeting (EOSAM).Experimental data from FWM-16 QAM wavelength conversion.