Energy-efficient Tbit/s optical interconnects are key elements for future communication systems. Three novel optical frequency comb sources are investigated, which have the potential of being integrated in chip-scale Tbit/s transmitters. Such frequency combs provide a large number of carriers. The equidistance of the comb lines helps to minimize spectral guard bands. For each type of comb source, coherent data transmission experiments show the potential for Tbit/s data transmission rates.

Energy-efficient Tbit/s optical interconnects are key elements for future communication systems. Three novel optical frequency comb sources are investigated, which have the potential of being integrated in chip-scale Tbit/s transmitters. Such frequency combs provide a large number of carriers. The equidistance of the comb lines helps to minimize spectral guard bands. For each type of comb source, coherent data transmission experiments show the potential for Tbit/s data transmission rates. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.

This book argues that a conscientiously objecting medical professional should receive an exemption only if the grounds of an objector’s refusal are reasonable. It defends a detailed, contextual account of public reasonability suited for healthcare, which builds from the overarching concept of Rawlsian public reason. The author analyzes the main competing positions and maintains that these other views fail precisely due to their systematic inattention to the grounding reasons behind a conscientious objection; he argues that any such view is plausible to the extent that it mimics the ‘reason-giving requirement’ for conscience objections defended in this work. Only reasonable objections can defeat the prior professional obligation to assign primacy to patient well-being, therefore one who refuses a patient’s request for a legally available, medically indicated, and safe service must be able to explain the grounds of their objection in terms understandable to other citizens within the public institutional structure of medicine. The book further offers a novel policy proposal to deploy the Reasonability View: establishing conscientious objector status in medicine. It concludes that the Reasonability View is a viable and attractive position in this debate. A New Theory of Conscientious Objection in Medicine: Justification and Reasonability will be of interest to researchers and advanced students working in bioethics, medical ethics, and philosophy of medicine, as well as thinkers interested in the intersections between law, medical humanities, and philosophy.

To keep up with the ever-increasing data transmission speed needs, data center interconnects are scaling up to provide multi-Tbit/s connectivity. These links require a high number of WDM channels, while the associated transceivers should be compact and energy efficient. Scaling the number of channels, however, is still limited by the lack of adequate optical sources. In this book, we investigate novel chip-scale frequency comb generators as multi-wavelength light sources for Tbit/s WDM links.

The increasing demand for high capacity, low cost, high compact and energy efficient optical transceivers for data center interconnects requires new technological solutions. In terms of transmitters, optical frequency combs generating a large number of phase coherent optical carriers are attractive solutions for next generation datacenter interconnects, and along with wavelength division multiplexing and advanced modulation formats can demonstrate unprecedented transmission capacities. In the framework of European project BIG PIPES (Broadband Integrated and Green Photonic Interconnects for High-Performance Computing and Enterprise Systems), this thesis investigates the generation of optical frequency combs using single-section mode-locked lasers based on InAs/InP Quantum-Dash and InGaAsP/InP Quantum-Well semiconductor nanostructures. These novel light sources, based on new active layer structures and cavity designs are extensively analyzed to meet the requirements of the project. Comprehensive investigation of amplitude and phase noise of these optical frequency comb sources is performed with advanced measurement techniques, to evaluate the feasibility of their use in high data rate transmission systems. Record Multi-Terabit per second per chip capacities and reasonably low energy per bit consumption are readily demonstrated, making them well suited for next generation datacenter interconnects.

Optical communication systems carry the bulk of all data traffic worldwide. This book introduces multi-Terabit/s transmission systems and three key technologies for next generation networks. A software-defined multi-format transmitter, an optical comb source and an optical processing scheme for the fast Fourier transform for Tbit/s signals. Three world records demonstrate the potential: The first single laser 10 Tbit/s and 26 Tbit/s OFDM and the first 32.5 Tbit/s Nyquist WDM experiments.