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Nyquist sinc-pulse shaping provides spectral efficiencies close to the theoretical limit. In this paper we discuss the analogy to optical orthogonal frequency division multiplexing and compare both techniques with respect to spectral efficiency and peak to average power ratio. We then show that using appropriate algorithms, Nyquist pulse shaped modulation(More)
Cloud service providers use replication across geographically distributed data centers to improve end-to-end performance as well as to offer high reliability under failures. Content replication often involves the transfer of huge data sets over the wide area network and demands high backbone transport capacity. In this paper, we discuss how a(More)
As the number of wireless users and per-user bandwidth demands continue to increase, both the vendor and carrier communities agree that wireless networks must evolve toward more dense deployments. So-called " heterogeneous networks " are a commonly proposed evolution, whereby existing macro-cellular networks are supplemented with an underlay of small cells.(More)
Communications technology has great potential for helping other industries reduce their greenhouse gas emissions. Nevertheless, given the relentless growth of demand for communications services, telecommunications providers will need to transition to more energy-efficient technology in order to limit their own environmental footprint. Here we focus on(More)
A microring-based silicon modulator operating at 40 Gb/s near 1310 nm is demonstrated for the first time to our knowledge. NRZ-OOK signals at 40 Gb/s with 6.2 dB extinction ratio are observed by applying a 4.8 Vpp driving voltage and biasing the modulator at 7 dB insertion loss point. The energy efficiency is 115 fJ/bit. The transmission performance of 40(More)
We report a hybrid integrated external cavity laser by butt coupling a quantum dot reflective semiconductor optical amplifier and a silicon-on-insulator chip. The device lasers at 1302 nm in the O-band, a wavelength regime critical to data communication systems. We measured 18 mW on-chip output power and over 50-dB side-mode suppression ratio. We also(More)
—Advances in the development of colorless and non-directional reconfigurable optical add-drop multiplex-ers (ROADMs) enable flexible pre-deployment of optoelec-tronic regenerators (reshaping, retiming, and reamplifying known as 3R) in future optical networks. Compared to the current practice of installing a regenerator only when a circuit needs them,(More)
We report a Ge-on-Si photodetector without doped Ge or Ge-metal contacts. Despite the simplified fabrication process, the device shows a responsivity of 1.14 A/W at −4 V reverse bias and 1.44 A/W at −12V, at 1550 nm wavelength. Dark current is less than 1µA under both bias conditions. We also demonstrate open eye diagrams at 40Gb/s. A single adiabatic(More)
Lorentz reciprocity is a direct consequence of Maxwell equations governing the propagation of light in passive linear media with symmetric permittivity and permeability tensors. Here, we demonstrate the first active optical isolator and circulator implemented in a linear and reciprocal material platform using commercial Mach-Zehnder modulators. In a(More)