This thesis investigates the growth, fabrication, and performance of III-V semiconductor

quantum dot lasers epitaxially grown on silicon based substrates as an enabling

technology for the realization of low cost, size, weight, and power (cSWaP) photonic integrated circuits. The use of large area, low cost silicon or silicon on insulator (SOI) based

substrates as a photonic integration platform is attractive due to existing economies of

scale and potential to recycle advanced CMOS fabrication tools already developed for

silicon microelectronics. The indirect bandgap of silicon presents a major hurdle towards

the complete integration of photonic devices on silicon - in particular a laser. To circumvent inefficient light emission from silicon's indirect bandgap, current methods to

fabricate silicon-based lasers typically rely on a separate material for the generation and

amplification of light. These methods include integration of III-V materials onto silicon

via wafer bonding or direct epitaxial growth, as well as band-gap engineering of group

IV elements such as Ge or GexSn(1-x) grown on silicon for direct gap light emission.

Direct growth of high gain III-V compound semiconductors onto silicon substrates

is well suited for high volume applications. Unfortunately, large dislocation densities

typically result from the growth process due to fundamental material differences between

III-Vs and Si, which is detrimental to both the device efficiency as well as reliability.

In this thesis, we demonstrate III-V laser diodes epitaxially grown on silicon with world

record performance. Key to our approach is the use of III-V self-assembled quantum

dot light emitters in place of traditional quantum wells, offering advantages of reduced sensitivity to dislocations, reduced sensitivity to reflections/optical feedback, and low

values of threshold current (densities). In particular, the reduced sensitivity of quantum

dot active regions to dislocations allows us to employ direct epitaxial growth for the

integration of III-V quantum dot lasers on silicon substrates with minimal compromise

in light emission efficiency.

The human mind, along with the cognitive faculties of consciousness, language, memory, and imagination, has historically been positioned as what sets humans apart from other species and non-living systems. Though behavioral research on non-human animals in the field of animal studies—as well as recent work on the cognitive properties of technical systems—has decentered the human as uniquely cognitive, affect and emotion are still considered the dividing line that separates human from machine, and therefore remain the final frontier in AI research. But if the mechanical is so often conceptualized in opposition to the human and therefore devoid of affect, I ask, then why has the machine been a critical object and metaphor for the articulation of theories of human affect, emotion, and cognition? My project aims to answer this question by bringing into conversation the deeply intertwined histories of cognitive science, affect theory, automation, and computing. I explore the machine—with a particular emphasis on the android machine—as both a material object and metaphor for selfhood, privileging affect-laden gestures displayed by machines, affective encounters between humans and machines, and the ways in which our technological inventions have influenced—and continue to influence—theories of human cognition and affect, just as our views of the mind have shaped our understandings of the machine. The machine—and by extension, the mechanical—has always figured into our conception of the human, serving as a metaphor for both what the human is and is not, but not always in ways that have been clearly articulated or understood. An overwhelming tendency has been either to reduce the human to the mechanical or to anthropomorphize the inanimate, which reinforces the anthropocentric binary between the human and non-human. My approach takes up the human and various mechanical objects—automaton, computer, chatbot, and emotional robot—as actors capable of displaying affect and engaging in the affective encounter. I discuss affective beings and objects, both living and non-living, in an inclusive framework that evades the dominant binaries of human/nonhuman and anthropomorphization/dehumanization, privileging embodied affect in both biological beings and technical systems. Central to my examination is an exploration of how these humanoid technologies have historically been—and continue to be—gendered and feminized.

—Giorgina Samira Paiella

As part of the Townsend Center's 1997-98 "Futures" program, Alan Liu conducts a full-scale inquiry into the prospects for literary knowledge in an information age driven by digital technology, management systems and corporate economics. His respondents, Miryam Sas, Albert Ascoli, and Sharon Marcus, Professors of Comparative Literature and East Asian Languages, Italian Literature, and English, respectively, enrich the dialogue by posing questions to Liu and by pointing beyond him to other ways of envisioning questions of literary studies.