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  1. Electronic analog to digital converters (ADCs) are running up against the well-known bit depth versus bandwidth trade off. Towards this end, radio frequency (RF) photonic-enhanced ADCs have been the subject of interest for some time. Optical frequency comb technology has been used as a workhorse underlying many of these architectures. Unfortunately, such designs must generally grapple with size, weight, and power (SWaP) concerns, as well as frequency ambiguity issues which threaten to obscure critical spectral information of detected RF signals. In this work, we address these concerns via an RF photonic downconverter with potential for easy integration and field deployment by leveraging a novel, to the best of our knowledge, hybrid microcomb/electro-optic comb design.

    Free, publicly-accessible full text available December 23, 2023
  2. There is growing evidence on the importance of psychological safety, or how comfortable participants feel in sharing their opinions and ideas in a team, in engineering team performance. However, how to support it in engineering student teams has yet to be explored. The goal of this study was to investigate whether a video intervention with assigned roles could foster psychological safety in student engineering teams. In addition, we sought to explore the impact of the frequency of the videos and the utility of the roles on the self-efficacy of students and the perceived psychological safety of the team. Specifically, this study introduces video interventions and the four lenses of psychological safety (Turn-Taking Equalizer, Point of View Shifter, Affirmation Advocate, and Creativity Promoter), and seeks to determine their effectiveness at increasing psychological safety self-efficacy and individual levels of psychological safety. A pilot study was completed with 54 participants (36 males, 17 females, 1 non-binary/third gender) enrolled in a cornerstone engineering design course. Over 10 weeks, data was collected at 5 time points. The results present four key findings. Most notably, 1) a video educating all students about psychological safety in general was effective in improving psychological safety self-efficacy and students retainedmore »this information to the end of the project;2) intervention groups taught to use the four lenses did not have a statistically significant higher level of psychological safety than non- intervention groups; and 3) intervention groups perceived the use of the lenses to increase psychological safety. These results provide a baseline understanding that is needed to support psychological safety including: when to intervene, how to intervene, and how frequently to intervene.« less
    Free, publicly-accessible full text available August 1, 2023
  3. Research on psychological safety has been growing in recent years due to its role in promoting creativity and innovation, among other items. This is because teams with high levels of psychological safety feel safe to express ideas and opinions. While we are becoming more aware of the importance of psychological safety in teaming, there is limited evidence in how to facilitate or build it within teams, particularly in an educational context. This paper was developed to respond to this research void by identifying the impact of teaming interventions aimed at improving psychological safety in engineering design student teams. Specifically, we studied two cohorts of students in a cornerstone design class (N = 414 students), one who received a series of video interventions and introduced role playing (intervention) and one who did not (control). These role assignments — referred to as the Lenses of Psychologically Safety - were created to promote key leadership attributes that have been shown to be crucial in facilitating psychologically safe teams. To compare the utility of the intervention, Psychological Safety was gathered at 5 key time points of a multi-week design project. The results identified three key findings. First, the interventions were successful in increasing psychologicalmore »safety in engineering teams. In addition, the results indicated the utility of the Lenses of Psychological Safety throughout the design process. Finally, the results identified that groups who used these lenses had higher perceptions of Psychological Safety in their teams. Overall, these results indicated that psychological safety can be improved in engineering education through the intervention methods described within.« less
    Free, publicly-accessible full text available August 1, 2023
  4. Improving team interactions in engineering to model gender inclusivity has been at the forefront of many initiatives in both academia and industry. However, there has been limited evidence on the impact of gender-diverse teams on psychological safety. This is important because psychological safety has been shown to be a key facet for the development of innovative ideas, and has also been shown to be a cornerstone of effective teamwork. But how does the gender diversity of a team impact the development of psychological safety? The current study was developed to explore just this through an empirical study with 38 engineering design student teams over the course of an 8-week design project. These teams were designed to be half heterogeneous (either half-male and half- female, or majority male) or other half homogeneous (all male). We captured psychological safety at five time points between the homogenous and heterogenous teams and also explored individual dichotomous (peer-review) ratings of psychological safety at the end of the project. Results indicated that there was no difference in psychological safety between gender homogenous and heterogenous teams. However , females perceived themselves as more psychologically safe with other female team members compared to their ratings of male teammore »members. Females also perceived themselves to be less psychologically safe with male team members compared to male ratings of female team members, indicating a discrepancy In perceptions between genders. These results point to the need to further explore the role of minoritized groups in psychological safety research and to explore how this effect presents itself (or is covered up) at the team level.« less
    Free, publicly-accessible full text available August 1, 2023
  5. Abstract

    Numerous Phanerozoic limestones are comprised of diagenetic calcite microcrystals formed during mineralogical stabilization of metastable carbonate sediments. Previous laboratory experiments show that calcite microcrystals crystallizing under conditions similar to those that characterize meteoric diagenetic settings (impurity-free, low degree of supersaturation, high fluid:solid ratio) exhibit the rhombic form/morphology, whereas calcite microcrystals crystallizing under conditions similar to those that prevail in marine and marine burial diagenetic settings (impurity-rich, high degree of supersaturation, low fluid:solid ratio) exhibit non-rhombic forms. Based on these experimental observations, it is proposed here that rhombic calcite microcrystals form exclusively in meteoric environments. This hypothesis is tested using new and previously published textural and geochemical data from the rock record. These data show that the vast majority of Phanerozoic limestones characterized by rhombic microcrystals also exhibit petrographic and/or geochemical evidence (depleted δ13C, δ18O, and trace elements) indicative of meteoric diagenesis whereas non-rhombic forms are associated with marine burial conditions. By linking calcite microcrystal textures to specific diagenetic environments, our observations bring clarity to the conditions under which the various microcrystal textures form. Furthermore, the hypothesis that rhombic calcite microcrystals form exclusively in meteoric environments implies that this crystal form may be a useful textural proxy for meteoric diagenesis.

  6. We demonstrate the use of a dual comb photonic system for downconversion and disambiguation of RF signals ranging from 4.3 GHz to 17.3 GHz. Our system has future potential for miniaturization, a key for deployment in real-world applications.

  7. This paper investigates team psychological safety (N=34 teams) in a synchronous online engineering design class spanning 4 weeks. While work in this field has suggested that psychological safety in virtual teams can facilitate knowledge-sharing, trust among teams, and overall performance, there have been limited investigations of the longitudinal trajectory of psychological safety, when the construct stabilizes in a virtual environment, and what factors impact the building of psychological safety in virtual teams. The results of this study identified that the construct of psychological safety took more time to become a reliable construct in virtual design teams, but once it stabilized, it did not change. Additionally, qualitative findings point to issues with communication and conflict across various stages of the design process in the development of psychological safety. Finally, we identify potential interventions to enhance team mental model development in the early phases of virtual teaming to support team psychological safety.
  8. Abstract

    Owing in large part to the advent of integrated biphoton frequency combs, recent years have witnessed increased attention to quantum information processing in the frequency domain for its inherent high dimensionality and entanglement compatible with fiber-optic networks. Quantum state tomography of such states, however, has required complex and precise engineering of active frequency mixing operations, which are difficult to scale. To address these limitations, we propose a solution that employs a pulse shaper and electro-optic phase modulator to perform random operations instead of mixing in a prescribed manner. We successfully verify the entanglement and reconstruct the full density matrix of biphoton frequency combs generated from an on-chip Si3N4microring resonator in up to an 8 × 8-dimensional two-qudit Hilbert space, the highest dimension to date for frequency bins. More generally, our employed Bayesian statistical model can be tailored to a variety of quantum systems with restricted measurement capabilities, forming an opportunistic tomographic framework that utilizes all available data in an optimal way.

  9. We demonstrate optical frequency division of an octave-spanning large repetition rate microcomb to an electronically-detectable frequency in an all-silicon nitride dual microcomb platform.