bluuebunny/crossref_metadata_2025 huggingface dataset:
Masculinity, Marginalization, And Patriarchal Violence
Authors: Levell Jade
Published: January 2023

In this chapter the author outlines the premise of the study and introduces the core theoretical concepts that underpin the rest of the book. This study uses gender theory to explore the participants’ narratives, resulting in an identification of different and at times competing masculinity performances affected by intersectional identities through the life course. The conceptualization of masculinity as a theoretical lens is explored, using Connell’s masculinity theory. The author situates masculinities within a wider understanding of patriarchy. Working definitions of on-road and gang involvement are outlined.
Learning How To Be A Man On-Road
Authors: Levell Jade
Published: January 2023

In Chapter 4, the beginnings of the participants’ masculine biographies were outlined. They revealed the ways in which the participants inhabited a subordinate masculinity while living under the shadow of the DVA perpetrator in the private realm of home. Participants then sought opportunities outside the home where they were able to capitalize on how ‘hard’ and tough their home experiences had made them, added to the residual anger that they carried and looked for an outlet to express. Through these means they developed an emerging protest masculinity, propped up by the pursuit of opportunities for material gain, which started their journeys on-road.
Love and Fear
Authors: Levell Jade
Published: January 2023

In this chapter the author explores friendships and intimate relationships. Reflections on gang ties and the role of the gang as family are explored, as is the impact that bereavement had when peers were killed in gang-related serious youth violence. Narratives of relationships with participants’ mothers and wider family are explored. Attitudes to women as intimate partners were also discussed, with a focus on violence against women. Some participants disclosed that they had perpetrated abuse against female partners in the past. The theoretical frame of cathexis is used to examine the tensions of love and fear that laced the participants’ narratives.
Broken Solidarities
Authors: Anderl Felix
Published: January 2023

This book analyses the fragmentation of a social movement and the rise of a new form of transnational rule. Its question is derived from a transnational activist meeting. The activists have been organizing against capitalist development practices – embodied by the World Bank Group – for over three decades, but nowadays they feel powerless vis a vis the institution. Although they are convinced that development projects are as devastating as ever, they can only dream of the levels of mobilization they brought to the streets during the 1990s. Perplexed by this decline, they ask themselves: ‘The movement is so fragmented. How has that happened?’ The book examines activists’ struggles to sustain their momentum and shows how the opening-up of world economic institutions contributed to complex rule in global governance, creating access for some while weakening their critique and fragmenting the overall social movement. Bridging International Relations and social movement studies, it observes international organizations and social movements in their interaction, demonstrating how social movements are divided and ruled in the absence of a ruler. Zooming into the Extractive Industries Review and the Civil Society Policy Forum, the book reconstructs how this happens through five mechanisms (economization, incorporation, legitimation, professionalization, and regulation) which both constitute complex rule in global governance and keep the social movement in fragmentation.
Knowing, Remembering, Showing But Still Not Seeing: Critical Praxis, Slavery and the Modern ‘We’
Authors: Fierke K.M.
Published: January 2023

In this chapter, Karin Fierke alerts us to how Kratochwil’s notion of praxis, understood as acting here and now, relates past and future to present situations. History, she argues, is remembering, and as such always part of a future project. What stitches together past and future are our present concerns. From this point of departure, Fierke problematizes the ‘we’ that constitutes David Hume’s common world of ‘commerce and conversation’ and wonders how we can see those who have been written out of history. She takes the issue of slavery as her example, beginning with Hume’s own troubling silence on the transatlantic slave trade in which his native Scotland was involved heavily. She then moves on to the ‘eerie and troubling silence’ surrounding Abraham Lincoln’s Gettysburg Address and his inability to ‘see’ the real victims of slavery when constituting the ‘we’ of the union rejoining North and South after the American civil war. Her chapter ends with reflections on the importance of redefining a global ‘we,’ as the subject of conversation.
Sociological Engagement with the Struggle for a Just Transition in South Africa
Authors: Cock Jacklyn
Published: January 2023

The chapter details attempts by researchers at the Society, Work and Politics Institute (SWOP) to empower the marginalized classes through critically engaged research. Such attempts were based on two sociological initiatives; first, a trade union project in which SWOP participated, mainly in the form of ‘public sociology’ – disseminating instrumental knowledge to a non-academic audience – and, second, a SWOP project which involved working closely with popular movements in the production of new sociological knowledge. Although both projects aimed to empower ordinary workers and social movements led by the marginalized groups, the two projects differed in approach and process. The chapter unpacks this difference by highlighting how the methodology of the ‘critical engagement’ (horizontal and dialogic) created spaces for dialogue and exchange that was intrinsically empowering, while the public sociology approach (vertical and didactic) was more limited in the sense of only containing that potential.
Participatory Action Research for Food Justice in Johannesburg : Seeking a More Immediate Impact for Engaged Research
Authors: Kesselman Brittany
Published: January 2023

This chapter describes a food justice research project in Johannesburg, South Africa, and argues that the use of participatory action research (PAR) methods can contribute to social change. In light of historical factors, such as colonialism and apartheid, that have contributed to the contemporary food crisis in Johannesburg, it considers how PAR may empower research participants through awareness raising, recognition of embodied knowledge and an emphasis on reciprocity. Despite the limitations imposed by academic research project time frames and bureaucratic processes, it suggests that the use of diverse, creative research methods under the PAR umbrella may help food justice research contribute more directly to social transformation.
Critically Engaged Sociology in Turkey and ‘Sociology across the South’
Authors: ment Ç elik Erc ü
Published: January 2023

This chapter on Turkey, informed by the South African experience, focuses on the conditional difference between the concepts of ‘critical engagement’ and ‘public sociology’ and argues that critical engagement and the knowledge produced through it bear a Southern character. The author uniquely adds a new dimension to Burawoy’s ‘Southern sociology’ perspective and conceptualizes a ‘sociology across the South’ in his particular attempt to explain the difference between the concepts of critical engagement and public sociology. The first part of the chapter reflects on the critical engagement and positioning of academics in a response to a permanent condition of radical social change in Turkey since the 1950s. The second part underlines the knowledge production at the intersection of the academic and political practices around the debate on Asiatic mode of production and agricultural production that began in the 1960s in Turkey.
The Limits of EUrope
Authors: Foster Russell , Grzymski Jan
Published: January 2023

In his fifth-century BCE chronicle of the Graeco-Persian Wars, Herodotus describes a challenge that European scholars have faced for two and a half millennia (Drace-Francis, 2013: 1). Since Antiquity, discussions of just what ‘Europe’ is, descriptively and normatively, have not been resolved and consensus has been reached that multiple ‘Europes’ exist. Recent events in Europe, though, suggest that while the boundaries of Europe are, and will forever remain, quite unknown, the boundaries of EUrope are becoming identifiable.
De-Europeanisation after Brexit: Narrowing and Shallowing 1
Authors: Outhwaite William
Published: January 2023

Is the European Union (EU) in a state of crisis? Over recent years, a series of systemic and spontaneous challenges, including Brexit, the rise of Euroscepticism and the Eurozone and refugee crises, have manifested in landmark moments for European integration.
First published as a special issue of the journal Global Discourse, this edited collection investigates whether these crises are isolated phenomena or symptoms of a deeper malaise across the EU. Experts from across disciplines analyse and rethink the forces which pull Europeans together, as well as those which push them apart.
Response to William Outhwaite
Authors: Spence David
Published: January 2023

Having read with great expectation and a certain dose of anxiety the two chapters written by Ben Rosamond and William Outhwaite, a non-academic and long-time practitioner of European affairs can only rejoice at the multi-layer analysis proposed to the reader as a tentative explanation of the multiple setbacks the EU integrative process is currently experiencing. For anyone dealing on a daily basis with the political challenges arising from the many unfolding crises, be it the migration inflows, the terrorist attacks, the eurozone fragilities or the growing internal divisions on foreign policy, a comprehensive interpretation about the unwinding of some of the key ingredients that allowed over past decades the European integration to successfully progress stands as a welcome assistance. It helps negotiators to understand the nature of the stalemate they face when they gather today helplessly in long and ineffective EU meetings.
Victimhood as Victory: The Role of Memory Politics in the Process of De-Europeanisation in East-Central Europe
Authors: Vermeersch Peter
Published: January 2023

Gerard Delanty’s central thesis is that Europeans should not worry about the resurgence of nationalism.
He distinguishes a new kind of nationalism exemplified by recent developments in Scotland and Catalonia and suggests these phenomena pose more of a threat to national polities than they do to the institutions of the EU.
The rise of individualism, he argues, has undermined the appeal of collective identities including a collective European identity. He points to a new form of identification with a more cosmopolitan vision of Europe among young Europeans. In my response, I would like to set out three stages in the development of modern Europe to contrast with the three phases of development of nationalism that Gerard Delanty has described.
Seeing Like a EUropean Border: The Limits of EUropean Borders and Space
Authors: Foster Russell
Published: January 2023

Is the European Union (EU) in a state of crisis? Over recent years, a series of systemic and spontaneous challenges, including Brexit, the rise of Euroscepticism and the Eurozone and refugee crises, have manifested in landmark moments for European integration.
First published as a special issue of the journal Global Discourse, this edited collection investigates whether these crises are isolated phenomena or symptoms of a deeper malaise across the EU. Experts from across disciplines analyse and rethink the forces which pull Europeans together, as well as those which push them apart.
Democracy beyond Hegemony
Authors: Purcell Mark
Published: January 2023

This chapter asks whether Laclau and Mouffe are the right theoretical partners for thinking about the project of democracy today. It concludes that they still have quite a lot to offer that project, but it also suggests we should be wary of embracing their thought too wholeheartedly, specifically because of their fondness for Gramsci and hegemony, and perhaps also, as a result, their willingness to engage the state and its institutions in the struggle for democracy.
The Post-Marxist Gramsci
Authors: Martin James
Published: January 2023

Gramsci’s ideas, particularly his formulation of cultural and ideological ‘hegemony’, have been a vital reference point in post-war Marxism and radical political thinking generally. Laclau and Mouffe’s recasting of hegemony in a post-Marxist idiom continued a wider tendency to amplify a specific aspect of Gramsci’s work, largely by neglecting consideration of his historical context or political and organisational commitments. By expanding hegemony into a radical theory of social constitution, I argue, Laclau and Mouffe drew upon Gramsci effectively to distance themselves from much of his legacy. This, I suggest, exemplified an interpretive attitude of ‘mourning’ that contrasts with the tendency to a ‘left melancholia’ that seeks an authentic radical subject prior to politics.
Epilogue
Authors: Sergi Anna
Published: January 2023

Nonna, do you like my bubbles? Always with these bubbles! Be careful, don’t throw the soap on the floor! I can almost see her, bella mia. I can still see how her face would contort when singing that song about the Madonna, full of pietas, full of pain and hope. She was a modest woman, my grandmother, never showing too much emotion. But her last time in Polsi, she remembered, she was singing, she was feeling it all deep down. She did cry. And every time since, this song gave her some tears.
Interruption
Authors: Hill David
Published: January 2023

Between chapters there is a brief interruption to consider the need for a humanism of the other that can speak to the peculiarity of human responsibility in the world but that does exclude nonhuman others from the moral universe. It is argued that we need an understanding of moral encounter that limits itself to the human encounter of others but that is fundamentally undiscriminating about what it encounters. This interruption then sets us on the path to an account of the moral gravity of animals as an interruptive and moving force.
Accession
Authors: Hill David
Published: January 2023

The fourth chapter sets off from the point that, if the Anthropocene marks a time when the human becomes the most salient force in the geological record, then it is high time we took seriously our moral responsibility for geological processes and entities. It is argued that if we set aside human temporality and let go of anthropocentric ideas of integrity and persistence, then we can see the geologic as both interruptive and indifferent, and in both ways a challenge to the human projection into the world that demands careful navigation and responsible communication. This would mark the accession of the geologic to our moral universe. We would then not only assume responsibility for our footprint in the world but also take on the task of being for geology even though these precarious existences are unlike existence as we presently understand it.
Making Models into Public Objects
Authors: Ballo Rokia , Pearce Warren
Published: January 2023

Abstract and Keywords to be supplied.
Genomic Medicine and the Remaking of Human Health
Authors: Martin Paul
Published: January 2023

The UK is playing a world leading role in the contemporary development of genomics – the decoding of our DNA – creating powerful technology platforms that may have profound consequences for the future of healthcare, civil liberties and personal identity. These developments have moved centre stage during the pandemic with the massive increase in gene sequencing for tracking Coronavirus. This chapter will examine the social implications of the growing use of genomics technologies and analyse how they are contributing to an important shift in how we understand health. This emphasises the biological and individualised nature of disease in contrast to the social determinants of health and illness, supporting an increasingly biomedicalised understanding of the human.
(Genome) Editing Future Societies
Authors: Morrison Michael
Published: January 2023

Abstract and Keywords to be supplied.
Introduction
Authors: Michelsen Nicholas , Bolt Neville
Published: January 2023

In this introduction, Michelsen and Bolt examine how forces of change today seem to be reconfiguring the lines on our maps. In response to migration, pandemics, and shocks of nature, the state is flexing its muscles and seeking to redraw those lines—only more emphatically than before. The authors ask whether our future is therefore fated to be the past of separate nations and sharply drawn borders? Or will networks come to displace the state, as was widely promised after the end of the Cold War. This introduction sets out our attraction to mapping in seeking to make sense of our turbulent age, why the state and the network both provide faulty maps of the present, and why we need unmapping.
Rengger, History, and the Future of International Relations
Authors: Whatmore Richard
Published: January 2023

Nicholas Rengger had a vision of the practice of international relations transformed by engagement with intellectual historians and political philosophers. What this entailed in full never became clear because of his early death. That there was a mission and a vision is clear from the chapters here collected. The ‘Afterword’ probes some of the responses to Rengger’s work, especially to his Anti-Pelagian Imagination. It goes on to consider the Hungarian historian of political and economic thought István Hont’s work as a related and in some respects parallel critique of the study of international relations to that of Rengger.
‘You Are No More Required’: COVID-19 Unmasks False Development Policies
Authors: Akhter Farida
Published: January 2023

Bangladesh has followed the neoliberal development strategy dictated by the World Bank, IMF and other international agencies. Export-oriented industrialization policy released people from their predominantly agrarian livelihood to become cheap labour for ready-made garment (RMG) industries and overseas workers. Many RMG workers were thrown out of their jobs soon after the COVID-19 pandemic started in 2020. The owners of the factories declared ‘you are no more required’; but the workers were not welcomed back to their village homes either. They are not required in the farming households, where they previously belonged. This chapter highlights the effects of the lockdown on RMG workers. But their precarious situation was not only due to COVID-19 alone: RMG workers were not being paid regularly; most workers lost three to five months of pay even before COVID-19 started, and were already living in very difficult situations.
Offshore: Lockdown Topographies 1
Authors: Perera Suvendrini
Published: January 2023

Walking, as Michel de Certeau noted, is also rhetoric. The selection of a path is an act of composition akin to the turning of a phrase. A style of walking, like style in writing, ‘connotes a singular’, a ‘way of being in the world’ and a particular ‘processing of the symbolic’. In the annals of COVID-19, walking narratives already have their own special subset.
This brief chapter takes the form of a walking journal during lockdown in the Western Australian port city of Fremantle (Walyalup) in Western Australia in the first months of the pandemic in 2020. Taking as a point of departure Rebecca Solnit’s discussion of walking as a form of investigation, not only of landscapes but of broader histories of place, the essay connects the Australian past and present to contemporary global intersections of the pandemic. At a crossroads of temporalities and topographies, the chapter explores the connections between landscapes, names and histories in a settler colonial society. It reflects on borders, local and global, as they are remade and unmade by the pandemic, in the context of Australia’s self-identity as an ‘island nation’.
#NoGoingBack: Queer Leaps at the Intersection of Protest and COVID-19 1 , 2
Authors: Haritaworn Jin
Published: January 2023

The concurrency of quarantine and protest has highlighted the trappings of a modernist realism whose conservative solutions reveal a paucity of methods and dreams. The wins that the uprisings against anti-Black police violence have put on the horizon, from the dismantling of carceral institutions to the uplifting of alternatives, have been long seeded by social movements that demanded the impossible. This includes ancestors, many of whom Black, queer and abolitionist, who prepared to take fantastic leaps, in the words of the Combahee River Collective. The following meditation holds up this legacy in order to reckon with the racism accompanying this latest crisis, from the Orientalist origin story of the coronavirus to a global quarantine paradigm that is haunted by racial capitalism. At the dystopic crossroad of the pandemic and the uprisings, a multiracial and multi-species spectre of planetary interdependence appears. This is illustrated by a mutual aid movement that uses digital and offline tactics in order to norm beyond the normal. In the place of a state-led surveillance and a single-issue environmentalism that are hostile to those most vulnerable to the virus, an urban environmental justice becomes palpable whose methods are queer.
End of the Road
Authors: Riggs William
Published: January 2023

Since the earliest days of civilization streets have played an important role in shaping society but over time a focus on roads design for automotive travel have changed their role in cities. This book challenges readers to revolutionize their roadways—end the idea of a road and reimagine the street. Active streets have long been transportation conduits but they have also served as economic, social, cultural and natural functions. This book covers those trends discussing how streets can be more complete and livable. It evaluates streets in cities ranging from London to San Francisco and New Dehli to Chicago looking at cases of how planners, engineers, policy makers and citizens can evolve the idea of what their streets can be. The book challenges readers to move beyond old ideas and see how streets can stimulate urban vitality and community regeneration, making change in their own communities.
A Recent History of The Street
Authors: Riggs William
Published: January 2023

This chapter focuses on a basic history of the street and how design has changed over time. This offers a foundation for more radical street designs offered further along in the book. The chapter provides a review of the form of street since the Industrial Revolution and illustrates the changes in standard street design over the past century and half.
The Street As Economic Space
Authors: Riggs William
Published: January 2023

This chapter focuses on the street as economic space and looks at research into the economic dividend benefits of walking and biking improvements in Midwestern cities like Louisville, Kentucky, and Chicago, Illinois, where practicing planners and policy makers are thinking of streets as tools for economic regeneration. It then transitions to some of the experiments taking place in London to show what planners can do to reshape the economics of a neighborhood by harnessing the power of the street.
The Street as a Natural Space
Authors: Riggs William
Published: January 2023

Chapter 7 focuses on how streets can be designed with nature. It frames this first from a macro perspective on how cities can become more green. It then focuses a lens of international design case studies of how nature can be integrated into streets. These focus on green laneways and alleys, as well as how many cities are embracing a trend toward biophilic streets.
Forced Relocations
Authors: Peterie Michelle
Published: January 2023

This chapter concerns the use of involuntary movement within Australia’s immigration detention network. Against the backdrop of the previous chapter, it shows that the practice of regularly relocating detainees within the detention system attacks their networks of care and resistance. While detention facilities are often envisaged as places of confinement, forced mobility is an important aspect of how these carceral institutions enact power. Instability, despair and compliance are produced not only through the bleakness of institutional life, but also through the forced transfer of detainees between detention facilities and away from the visitors who provide social, emotional and instrumental support.
Noise analysis in outdoor dynamic speckle measurement
Authors: Levchenko Mikhail , Stoykova Elena , Ivanov Branimir , Nedelchev Lian , Nazarova Dimana , Choi Kihong , Park Joongki
Published: January 2023

The dynamic speckle method (DSM) is an effective tool for the estimation of speed of processes. The speed distribution is encoded in a map built by statistical pointwise processing of time-correlated speckle patterns. For industrial inspection, the outdoor noisy measurement is required. The paper analyzes the efficiency of the DSM in the presence of environmental noise as phase fluctuations due to the lack of vibration isolation and shot noise due to ambient light. The usage of normalized estimates for the case of non-uniform laser illumination is studied. The feasibility of the outdoor measurement has been proven by numerical simulations of noisy image capture and real experiments with test objects. Good agreement has been demonstrated in both the simulation and experiment between the ground truth map and the maps extracted from noisy data.
Spectra reconfiguration of a silicon microring resonator via double injection with different angles
Authors: Guo Chen , Yun Binfeng , Hu Guohua , Cui Yiping
Published: January 2023

A reconfigurable silicon microring filter, which is constructed by cascading a tunable Mach–Zehnder interferometer and a double injected silicon microring resonator with a variable input angle, is proposed and investigated. The spectra reconfigurations of the optical filter were simulated and analyzed using the transmission matrix method. The results show that when keeping the perimeter of the microring constant, the free spectral range (FSR) of the filter can be multiplied by adjusting the angle between the two injections. Moreover, by changing the coupling coefficients of the microring and the optical power ratio between the two injections, different types of spectral responses such as square, sinusoidal, and flat-top interleaver can be obtained. The device is simple and easy to integrate, and its capabilities to expand the FSR and spectral reconfiguration may have great potential in reconfigurable integrated optic chips.
Generation of extremely high-angle Bessel beams
Authors: Belloni Valeria V. , Froehly Luc , Billet Cyril , Furfaro Luca , Courvoisier Francois
Published: January 2023

We present a setup to generate tightly focused Bessel beams that is composed of a half-ball lens coupled with a relay lens. The system is simple and compact compared to conventional imaging of axicons based on microscope objectives. We experimentally demonstrate the generation of a Bessel beam with a 42° cone angle at 980 nm in air with a typical beam length of 500µm and a central core radius of about 550 nm. We numerically studied the effects of the misalignment of the different optical elements and the range of tilt and shift that are acceptable to obtain a regular Bessel beam.
Multi-channel THz perfect absorber using graphene-based Fibonacci photonic crystals
Authors: Dong Jiaming , Deng Xin-Hua , Zhang Pingsheng , Yuan Jiren
Published: January 2023

A graphene-based multi-channel THz perfect absorber is proposed in this paper. The absorber consists of a graphene layer, a Fibonacci quasi-periodic layer, a spacer, and a substrate. We demonstrate that the structure we proposed can lead to multi-channel perfect THz absorption because of the graphene surface plasmon polaritons and multiple photonic stop bands in this structure. The multi-channel working frequencies and absorption peaks can be flexibly tuned by controlling the incidence angle, size of component materials, and Fermi energy. Moreover, by adjusting the Fibonacci quasi-period orders of the structure, the number of working channels can be flexibly expanded without reoptimizing the structure size. Moreover, by adjusting the Fibonacci quasi-period orders of the structure, the number of working channels can be flexibly expanded without reoptimizing the structure size. Using existing technology, our design scheme is easy to realize, which will be helpful to promote the development and application of novel tunable optoelectronic devices.
Fast quantum-enhanced imaging with visible-wavelength entangled photons
Authors: Camphausen Robin , Sansa Perna Adrià , Cuevas Álvaro , Demuth Alexander , Arrés Chillón Javier , Gräfe Markus , Steinlechner Fabian , Pruneri Valerio
Published: January 2023

Quantum resources can provide supersensitive performance in optical imaging. Detecting entangled photon pairs from spontaneous parametric down conversion (SPDC) with single-photon avalanche diode (SPAD) image sensor arrays (ISAs) enables practical wide-field quantum-enhanced imaging. However, matching the SPDC wavelength to the peak detection efficiency range of complementary metal–oxide–semiconductor (CMOS) compatible mass-producible SPAD-ISAs has remained technologically elusive, resulting in low imaging speeds to date. Here, we show that a recently developed visible-wavelength entangled photon source enables high-speed quantum imaging. By operating at high detection efficiency of a SPAD-ISA, we increase acquisition speed by more than an order of magnitude compared to previous similar quantum imaging demonstrations. Besides being fast, the quantum-enhanced phase imager operating at short wavelengths retrieves nanometer scale height differences, tested by imaging evaporated silica and protein microarray spots on glass samples, with sensitivity improved by a factor of 1.351 ± 0.004 over equivalent ideal classical imaging. This work represents an important stepping stone towards scalable real-world quantum imaging advantage, and may find use in biomedical and industrial applications as well as fundamental research.
Suppressing the mechanochromism of flexible photonic crystals
Authors: Kraft Fabio A. , Harwardt Katharina , Schardt Jan , Nowotka Dirk , Gerken Martina
Published: January 2023

Photonic crystal slabs (PCS) are a promising platform for optical biosensing. Yet, flexible applications based on PCS for biosensing have been limited, as the mechanical properties influence the optical ones. Here, we show the suppression of the mechanochromism effect for flexible PCS. We obtained flexible photonic crystal slabs by sputtering of a dielectric 100 nm Nb2O5 high refractive index layer onto a flexible nanostructured polydimethylsiloxane (PDMS) substrate with 370 nm grating period. The PCS exhibit a guided mode resonance at around 650 nm. We demonstrate that these flexible photonic crystal slabs show less than 0.5 nm resonance shift for 4% strain and call them stabilized PCS (sPCS). We compare this to a resonance shift of ∼21 nm for ∼4% strain of a flexible photonic crystal with a flexible nanoparticle high index layer (mechanochromatic PCS, mPCS). This high resonance shift is expected from the Bragg equations, where 4% grating period change correspond to approximately 4% change of the resonance wavelength (i.e., ∼26 nm at a resonance wavelength of 650 nm), if changes in the mode effective refractive index are neglected. In a stretch series we obtain color-to-strain dependencies of 4.79 nm/% strain for mPCS and 0.11 nm/% strain for our stabilized sPCS. We analyze the suppression of the mechanochromism with detailed microscopy results. We observe that fissures and fractures form in the rigid waveguiding layer of the sPCS upon mechanical stress. An algorithm based on Holistically-Nested Edge Detection (HED) is used for automated counting of cracks. Rigid photonic crystal cells with sizes on the order of 10 µm to 100 µm are formed that explain the stable optical properties. Even more stable optical properties with less than 0.03 nm wavelength shift per 1% strain are demonstrated for sPCS with an additional dielectric 100 nm SiO2 low index layer beneath the Nb2O5 waveguide layer decoupling the waveguide further from the flexible PDMS substrate.
General framework of a two-dimensional complex wavelet for fringe projection profilometry
Authors: Han Mengqi , Chen Wenjing
Published: January 2023

Single-shot high-accuracy reconstruction of three-dimensional (3D) objects plays an essential role in many fields. Wavelet-based fringe projection profilometry (WFPP) is a popular single-shot imaging method due to its multiple-resolution analysis and non-contact property. However, the construction of mother wavelets for high-accuracy WFPP is still challenging. In this paper, a general framework of two-dimensional (2D) compact support complex wavelet employing the dual-tree concept combined with the one-dimensional (1D) asymmetric wavelet function is proposed. The constructed wavelet has an asymmetric frequency envelope in the radial direction and concentrated energy in a single quadrant of the frequency domain. A method that the constructed wavelet applied in dual-angle rotation-based 2D WFPP is presented for higher accuracy. The theoretical analysis of the proposed method is presented, and a comparison of frequency characteristics between the constructed wavelet and other popular wavelets is conducted. Computer simulations and experiments have demonstrated that the proposed method provides a better reconstruction of 3D shapes in single-shot WFPP.
High-resolution optical coherence tomography using gapped spectrum and real-valued iterative adaptive approach
Authors: Bai Yulei , Cai Shuying , Xie Shengli , Dong Bo
Published: January 2023

Optical coherence tomography (OCT) is a powerful imaging technique that is capable of imaging cross-sectional structures with micrometer resolution. After combining with phase-sensitive detection, it can sense small changes in the physical quantities inside an object. In OCT, axial resolution is generally improved by expanding the bandwidth of the light source. However, when the bandwidth is expanded discontinuously, the wavelength gap induces abnormal sidelobes when estimating OCT signals in the depth domain. This problem can lead to poor axial resolution. Herein, we present a method based on a real-valued iterative adaptive approach (RIAA) to achieve a high axial resolution under a discontinuous bandwidth condition. The method uses a weighted matrix to suppress the abnormal sidelobes caused by the wavelength gap and, therefore, can realize high-resolution measurements. A single-reflector OCT spectrum was first measured for validation, and its amplitude in the depth domain was estimated using different methods. The results indicate that the RIAA had the best capability of suppressing abnormal sidelobes, thereby achieving a high axial resolution. In addition, cross-sectional images and phase-difference maps of three different samples were measured. A comparison of the results validated the practical value of this method.
Versatile volumetric additive manufacturing with 3D ray tracing
Authors: Webber Daniel , Zhang Yujie , Picard Michel , Boisvert Jonathan , Paquet Chantal , Orth Antony
Published: January 2023

Tomographic volumetric additive manufacturing (VAM) is an optical 3D printing technique where an object is formed by photopolymerizing resin via tomographic projections. Currently, these projections are calculated using the Radon transform from computed tomography but it ignores two fundamental properties of real optical projection systems: finite etendue and non-telecentricity. In this work, we introduce 3D ray tracing as a new method of computing projections in tomographic VAM and demonstrate high fidelity printing in non-telecentric and higher etendue systems, leading to a 3x increase in vertical build volume than the standard Radon method. The method introduced here expands the possible tomographic VAM printing configurations, enabling faster, cheaper, and higher fidelity printing.
Tightly-coupled fusion of iGPS measurements in optimization-based visual SLAM
Authors: Yang Ze , Li Yanyan , Lin Jiarui , Sun Yanbiao , Zhu Jigui
Published: January 2023

The monocular visual Simultaneous Localization and Mapping (SLAM) can achieve accurate and robust pose estimation with excellent perceptual ability. However, accumulated image error over time brings out excessive trajectory drift in a GPS-denied indoor environment lacking global positioning constraints. In this paper, we propose a novel optimization-based SLAM fusing rich visual features and indoor GPS (iGPS) measurements, obtained by workshop Measurement Position System, (wMPS), to tackle the problem of trajectory drift associated with visual SLAM. Here, we first calibrate the spatial shift and temporal offset of two types of sensors using multi-view alignment and pose optimization bundle adjustment (BA) algorithms, respectively. Then, we initialize camera poses and map points in a unified world frame by iGPS-aided monocular initialization and PnP algorithms. Finally, we employ a tightly-coupled fusion of iGPS measurements and visual observations using a pose optimization strategy for high-accuracy global localization and mapping. In experiments, public datasets and self-collected sequences are used to evaluate the performance of our approach. The proposed system improves the result of absolute trajectory error from the current state-of-the-art 19.16mm (ORB-SLAM3) to 5.87mm in the public dataset and from 31.20mm to 5.85mm in the real-world experiment. Furthermore, the proposed system also shows good robustness in the evaluations.
Generation and control of the circle Olver beams
Authors: Wang Ziyu , Yang Haobin , Xu Danlin , Liang Zehong , Shui Lingling , Deng Dongmei
Published: January 2023

The circle Olver beams (COBs) generated by modulation on the basis of a new type of Olver beam are presented numerically and experimentally. The zeroth order COB is the circle Airy beam. We demonstrate auto-focusing of the COBs with both inward and outward accelerations, where the odd order COBs display auto-defocusing while the even order COBs (ECOBs) tend to focus more abruptly. We also explore the effect of the decay factor and the scaling factor on the beams’ focusing properties, such as the initial energy distribution, the focusing position, the focusing intensity and the focusing depth, by using the parity mode. In addition, we verify the self-healing property of the COBs. Finally, we set up an experimental platform to implement particle capture and manipulation with the ECOBs. Our results offer practical applications for particle manipulation, laser processing, etc.
Computational imaging with spectral coding increases the spatial resolution of fiber optic bundles
Authors: Dumas John P. , Lodhi Muhammad A. , Bajwa Waheed U. , Pierce Mark C.
Published: January 2023

Fiber optic bundles are used in narrow-diameter medical and industrial instruments for acquiring images from confined locations. Images transmitted through these bundles contain only one pixel of information per fiber core and fail to capture information from the cladding region between cores. Both factors limit the spatial resolution attainable with fiber bundles. We show here that computational imaging (CI) can be combined with spectral coding to overcome these two fundamental limitations and improve spatial resolution in fiber bundle imaging. By acquiring multiple images of a scene with a high-resolution mask pattern imposed, up to 17 pixels of information can be recovered from each fiber core. A dispersive element at the distal end of the bundle imparts a wavelength-dependent lateral shift on light from the object. This enables light that would otherwise be lost at the inter-fiber cladding to be transmitted through adjacent fiber cores. We experimentally demonstrate this approach using synthetic and real objects. Using CI with spectral coding, object features 5× smaller than individual fiber cores were resolved, whereas conventional imaging could only resolve features at least 1.5× larger than each core. In summary, CI combined with spectral coding provides an approach for overcoming the two fundamental limitations of fiber optic bundle imaging.
Forecasting the chaotic dynamics of external cavity semiconductor lasers
Authors: Kai Chao , Li Pu , Yang Yi , Wang Bingjie , Alan Shore K. , Wang Yuncai
Published: January 2023

Chaotic time series prediction has been paid intense attention in recent years due to its important applications. Herein, we present a single-node photonic reservoir computing approach to forecasting the chaotic behavior of external cavity semiconductor lasers using only observed data. In the reservoir, we employ a semiconductor laser with delay as the sole nonlinear physical node. By investigating the effect of the reservoir meta-parameters on the prediction performance, we numerically demonstrate that there exists an optimal meta-parameter space for forecasting optical-feedback-induced chaos. Simulation results demonstrate that using our method, the upcoming chaotic time series can be continuously predicted for a time period in excess of 2 ns with a normalized mean squared error lower than 0.1. This proposed method only utilizes simple nonlinear semiconductor lasers and thus offers a hardware-friendly approach for complex chaos prediction. In addition, this work may provide a roadmap for the meta-parameter selection of a delay-based photonic reservoir to obtain optimal prediction performance.
Unidirectional hybrid diode laser through the integration of a hook-shaped traveling-wave semiconductor optical amplifier and Taiji ring resonator
Authors: Zeng Siwei , Zhao Xiaolei , Sweatt Lance , Porter Chas , Zhu Lin
Published: January 2023

We demonstrate a unidirectional ring diode laser based on hybrid integration of a hook-shaped traveling-wave semiconductor optical amplifier (SOA) and a Taiji ring resonator. The additional crossover bending waveguide inside the silicon nitride Taiji ring introduces a non-reciprocal loss in the laser cavity while the gain is provided by a multiple depth etched hook-shaped SOA. We present the detailed design flow for both active and passive components of the unidirectional hybrid diode laser. This work paves the way to use a hook-shaped SOA-based hybrid platform for various applications including optical sensing, all-optical switching, photonic memories, and topological optics.
Laser cooling a membrane-in-the-middle system close to the quantum ground state from room temperature
Authors: Saarinen Sampo A. , Kralj Nenad , Langman Eric C. , Tsaturyan Yeghishe , Schliesser Albert
Published: January 2023

Many protocols in quantum science and technology require initializing a
system in a pure quantum state. In the context of the motional state
of massive resonators, this enables studying fundamental physics at
the elusive quantum–classical transition, and measuring force and
acceleration with enhanced sensitivity. Laser cooling has been a
method of choice to prepare mechanical resonators in the quantum
ground state, one of the simplest pure states. However, to overcome
the heating and decoherence by the thermal bath, this usually has to
be combined with cryogenic cooling. Here, we laser-cool an
ultracoherent, soft-clamped mechanical resonator close to the quantum
ground state directly from room temperature. To this end, we implement
the versatile membrane-in-the-middle setup with one fiber mirror and
one phononic crystal mirror, which reaches a quantum cooperativity
close to unity already at room temperature. We furthermore introduce a
powerful combination of coherent and measurement-based quantum control
techniques, which allows us to mitigate thermal intermodulation noise.
The lowest occupancy we reach is 30 phonons, limited by measurement
imprecision. Doing away with the necessity for cryogenic cooling
should further facilitate the spread of optomechanical quantum
technologies.
Single-shot photoacoustic imaging with single-element transducer through a spatiotemporal encoder
Authors: Zhao Yanyu , Wang Lihong
Published: January 2023

Current photoacoustic (PA) imaging modalities typically require either serial detection with a single-element transducer or parallel detections with an ultrasonic array, indicating a dilemma between system cost and imaging throughput. Photoacoustic topography through ergodic relay (PATER) was recently developed to address this bottleneck. However, PATER requires object-specific calibration due to varied boundary condition, and must be re-calibrated through pointwise scanning for each object before measurements, which is time-consuming and severely limits practical application. Here, we develop a new method, photoacoustic imaging through a spatiotemporal encoder (PAISE), which is capable of single-shot widefield PA imaging with a single-element transducer, and does not require object-specific calibration. We validated PAISE through comprehensive numerical simulations and experiments, and demonstrated that PAISE can image different objects with a single calibration. Together, these results highlight the potential of PAISE for significant impact in both scientific research and clinical applications.
Yeast derlin Dfm1 employs a chaperone-like function to resolve misfolded membrane protein stress
Authors: Kandel Rachel , Jung Jasmine , Syau Della , Kuo Tiffany , Songster Livia , Horn Casey , Chapman Claire , Aguayo Analine , Duttke Sascha , Benner Christopher , Neal Sonya E.
Published: January 2023

Protein aggregates are a common feature of diseased and aged cells. Membrane proteins comprise a quarter of the proteome, and yet, it is not well understood how aggregation of membrane proteins is regulated and what effects these aggregates can have on cellular health. We have determined in yeast that the derlin Dfm1 has a chaperone-like activity that influences misfolded membrane protein aggregation. We establish that this function of Dfm1 does not require recruitment of the ATPase Cdc48 and it is distinct from Dfm1’s previously identified function in dislocating misfolded membrane proteins from the endoplasmic reticulum (ER) to the cytosol for degradation. Additionally, we assess the cellular impacts of misfolded membrane proteins in the absence of Dfm1 and determine that misfolded membrane proteins are toxic to cells in the absence of Dfm1 and cause disruptions to proteasomal and ubiquitin homeostasis.