物理与天体物理最新文献

{"title":"UV Exposure Study of 1-Methylnicotinamide Chloride: Self-Preservation in a Simple NAD(P)⁺ Analog.","authors":"Alexander Engel, Henry Strasdeit, Stefan Fox, Ronny Löffler","doi":"10.1177/15311074261483400","DOIUrl":"10.1177/15311074261483400","url":null,"abstract":"<p><p>Chemical biosignatures, if present, are exposed to ultraviolet (UV) radiation at several locations in the solar system, including the martian surface. Solid thin-layer samples are commonly used to study the effect of UV irradiation on the stability of potential organic biosignatures in the laboratory and in space. Given the limitations of the layer deposition techniques previously used in astrobiology experiments, such as sublimation-recondensation and casting, antisolvent precipitation (<i>i.e.</i>, crystallization from solution by addition of a poor solvent) offers a promising alternative. We applied the latter technique to deposit optically opaque crystalline layers of 1-methylnicotinamide chloride ((MNA)Cl) for use in subsequent UV irradiation experiments. The 1-methylnicotinamide cation in (MNA)Cl serves as a model of hypothetical extraterrestrial nicotinamide-based redox cofactors related to NAD(P)⁺. Under UV irradiation (<i>λ</i> ≥ 224 nm), decomposition of (MNA)Cl occurred, but it ceased after ∼14 days, leaving a large fraction of the material intact. This behavior is attributed to the shielding effect of a photoproduct layer on the crystal surfaces and can be kinetically described by a first-order bounded decay model. Such \"self-preservation\" may enhance the survivability of certain organic biosignatures provided they form sufficiently thick (opaque) layers or crystals. The presence of either synthetic gypsum (CaSO₄·2H₂O) or halite (NaCl) had a minimal effect on the kinetic parameters of the UV decomposition of (MNA)Cl.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"950-966"},"PeriodicalIF":2.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Case for Integrating Astrobiology Before, During, and After Crewed Space Missions.","authors":"Celia Blanco, Anamaria Berea, Anurup Mohanty, Arunava Poddar, Rajat Bhushan Gupta","doi":"10.1177/15311074261484862","DOIUrl":"10.1177/15311074261484862","url":null,"abstract":"<p><p>The transition to sustained human space exploration is reshaping how astrobiology can be conducted. As missions extend beyond low Earth orbit and involve governmental and commercial actors, astrobiology is increasingly becoming embedded in complex operational and policy environments. These developments can be seen as a shift in the operational, interpretive, and governance contexts of astrobiology, affecting how investigations are conducted, how findings are interpreted, and how research is coordinated across mission phases. Here, we outline the implications of human presence for astrobiology research and its integration within evolving exploration architectures, and examine its role in future missions.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"944-949"},"PeriodicalIF":2.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148904946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Excitation Raman Spectroscopy of Carbonaceous Matter within Opaline Silica Sinters from Mars-Analog Hot Spring Settings: Implications for the Search for Extraterrestrial Biosignatures.","authors":"Rui-Lin Cheng, Carolina Munoz-Saez, Kathleen A Campbell, Joseph R Michalski, Andrew D Czaja, Steven W Ruff","doi":"10.1177/15311074261483387","DOIUrl":"10.1177/15311074261483387","url":null,"abstract":"<p><p>Silica sinters are promising astrobiology targets in the search for signs of past extraterrestrial life on Mars. Although terrestrial sinter morphologic features may serve as potential biosignatures at the macroscale, identification of carbonaceous matter (CM) within silica would offer substantial support for interpreting martian silica deposits as having a biologic association. Raman spectroscopy provides a means to identify both minerals and organics <i>in situ</i>. This technique has been employed to analyze CM in terrestrial sinters that consist of microcrystalline quartz and has also been deployed previously on Mars to search for organics. However, martian silica deposits are dominated by opaline silica rather than quartz, and a thorough examination of CM within terrestrial opaline silica by Raman spectroscopy is generally lacking. We investigated opaline silica sinters from northern Chile, an exceptional terrestrial analog for Mars, by Raman spectroscopy with multiple excitations. Our results show that strong fluorescence from opaline silica modifies CM Raman spectral signatures across excitation wavelengths. CM Raman spectra within opaline silica sinters vary both among facies and within individual samples, and they differ from those in Archean cherts. This study demonstrates that reliable interpretation of CM Raman spectra requires attention to host-matrix influences, excitation wavelength, and curve-fitting procedures.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"967-983"},"PeriodicalIF":2.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity Lost in Space: Discrimination and Exclusion in Astrobiology.","authors":"Arsev Umur Aydinoglu, Ozgur Kadir Ozer","doi":"10.1177/15311074261483886","DOIUrl":"10.1177/15311074261483886","url":null,"abstract":"<p><p>This study presents an analysis of diversity, equity, and inclusion in the U.S. astrobiology community. Using national survey data, we examined how gender, race, age, and career stage affect researchers' experiences with mentorship, funding, and career advancement. The results reveal disparities: female participants reported gender discrimination at seven times the rate of male respondents, and 85% of all respondents had encountered harassment. Nearly half experienced career interruptions, most commonly due to mental health challenges (57%), family obligations, or harassment. Other persistent barriers included difficulty meeting workplace expectations (84%), securing permanent positions (40%), and obtaining adequate funding (nearly one-third). Female researchers reported lower levels of workplace support and collegial respect than their male peers. While some institutions have begun implementing equity-focused practices, adoption across the field remains limited. Based on these findings, we recommend that institutions publicly report diversity metrics, establish targeted mentorship programs, and provide mental health support and parental leave policies. Addressing these systemic barriers is essential not only for ethical reasons but also for advancing astrobiology's mission, which depends on diverse perspectives and collaboration.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"984-997"},"PeriodicalIF":2.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Abiotic Background: Challenges and Opportunities in the Search for Evidence of Life Beyond Earth.","authors":"Alfonso Davila, Tori Hoehler, Svetlana Shkolyar, Michel Nuevo, Karyn Rogers, Laura M Barge, Alexis Bouquet, Jacob Buffo, Aaron Burton, Morgan Cable, H James Cleaves, Andrew D Czaja, Grégoire Danger, Moran Frenkel-Pinter, Christopher German, Stephanie Getty, Christopher Glein, Heather Graham, Kevin Hand, Sarah Hörst, Kristin Johnson-Finn, Wanying Kang, Ramanarayanan Krishnamurthy, Shannon MacKenzie, Aaron Noell, Frank Postberg, Andro Rios, Jeffrey Seewald, Barbara Sherwood Lollar, Andrew Steele, Ichiko Sugiyama","doi":"10.1177/15311074261484864","DOIUrl":"10.1177/15311074261484864","url":null,"abstract":"<p><p>The \"Exploring the Abiotic Background for Life Detection\" workshop was convened between March 31, 2025, and April 3, 2025, at the Carnegie Institution for Science in Washington, D.C. The workshop gathered scientists and technologists from different disciplines and career stages to consider the \"abiotic background\": recognizing, characterizing, and understanding the set of abiotic substances, structures, and processes that may result in potential false-positive or false-negative results in the search for evidence of life beyond Earth. To frame the conversation and ensure programmatic relevance, the workshop emphasized Ocean Worlds, while also leveraging lessons learned from modern and early Earth and Mars. Salient takeaways include the following: (1) a large abiotic background, potentially sustained over geologic timescales, could mimic, obscure, and alter biosignatures, posing risks of false positives and false negatives. Addressing these challenges requires balancing targeted and untargeted measurements within the constraints of robotic spacecraft payloads; (2) the search for signatures of life beyond Earth represents a sharp inflection point in spacecraft mission complexity and design. Stakeholders of such missions must strike a difficult balance between scientific aspirations and the technological constraints inherent to robotic spaceflight; (3) Ocean Worlds are a distinct class of habitable environments, each with unique evolutionary pathways, but collectively offering new opportunities to study organic chemical evolution; (4) there is a need to establish community-wide experimental standards and laboratory simulations to better constrain the range of abiotic chemistry and improve abiotic chemistry models to guide the design of spacecraft missions; (5) a unifying, predictive framework for abiotic chemical evolution could provide a robust baseline for interpreting mission data and guiding future exploration. This report seeks to catalyze a sustained and focused dialogue on how to best account for the abiotic background in the design of astrobiology spacecraft missions. By framing the issue both in terms of risks and scientific opportunities, we lay the groundwork for a richer, more integrated approach to the exploration of other worlds that benefits from continued cross-disciplinary input. We contend that advancing our understanding of the abiotic background now will directly inform and improve future astrobiological spacecraft missions, particularly in terms of payload selection and data interpretation.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":"927-943"},"PeriodicalIF":2.3,"publicationDate":"2026-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148966325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Room-Temperature Visible-Light Single-Photon Avalanche Detection in Grating-Coupled Post-CMOS Photonic Circuits","authors":"Marcus Westhues,Roman Burkard,Thomas Geruschke,Julia Hauser,Johannes Ewering,Stefan Dreiner,Aleksandar Nesic,Anna Lena Schall-Giesecke","doi":"10.1021/acsphotonics.6c01473","DOIUrl":"https://doi.org/10.1021/acsphotonics.6c01473","url":null,"abstract":"The integration of photonic circuits with on-chip single-photon detectors has emerged as a key enabling technology for highly scalable visible-wavelength photonic integrated circuits, underpinning advanced applications in quantum information processing and biophotonics. However, detecting weak optical signals down to the single-photon regime at specific wavelengths requires efficient interconnections between photonic waveguides and detectors. Here, we present an interconnect from silicon nitride photonic circuits to single-photon avalanche diodes (SPADs) on a standard 200 mm CMOS wafer integrated using post-CMOS integration. To realize this efficient interconnect, we optimized the interface by introducing metal reflector-assisted grating couplers for the target wavelengths 633 nm and 785 nm. To investigate the influence of the reflector on the efficiency of the interface, we conducted simulations and subsequent optimizations. In simulation, the grating-assisted interconnect achieves a coupling efficiency of 2.0 dB at 785 nm, representing a 6.4 dB improvement over the baseline design. To validate this improvement, we fabricated this structure with and without reflector and experimentally demonstrate detection of single photons at the target wavelengths. After post-CMOS integration, the utilized Fraunhofer IMS SPADs were operated at room temperature with an off-chip passive quenching circuit. Optical characterization showed an improvement by up to 4.5 dB by implementing reflectors. We show venues for improving the photon detection probability by correlating it with loss sources encountered in the fabricated devices. With these results, we demonstrate the applicability of post-CMOS integration and offer a photonic-integrated solution for detecting single photons from red to near-infrared wavelengths.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"11 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Programmable Non-Hermitian Synchronization of Light on a Silicon Photonic Processor","authors":"Ze-Sheng Xu,Nan Cheng,Mohammed S. Elmusrati,Rohan Yadgirkar,Andrea Cataldo,Rui Wen,Govind Krishna,Jun Gao,Ali W. Elshaari","doi":"10.1021/acsphotonics.6c01369","DOIUrl":"https://doi.org/10.1021/acsphotonics.6c01369","url":null,"abstract":"Synchronization is a widespread collective phenomenon in which coupled units with different microscopic states evolve toward a common macroscopic order. Across these systems, dissipation plays an organizing role, suppressing microscopic differences and steering coupled units toward a coherent collective state. Here, we harness engineered dissipation in a nonunitary photonic framework to synchronize light directly in the optical domain. Implementing row-stochastic transition matrices embedded in a unitary photonic network on a silicon photonic processor, we drive generic multimode optical fields toward a unique collective state with equal modal intensities and a globally locked phase─a process we term dissipation-induced phase synchronization. The synchronization rate and total optical power throughput are independently programmable, enabling control over the dissipative dynamics without compromising reconfigurability. These results recast dissipation as a functional resource and open a route to reconfigurable on-chip synchronization for classical and quantum photonic technologies.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"15 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi‐Dimensional Optical Encryption With Metasurface‐Enabled Perfect Vortex Beam Array","authors":"Huan Zhao, Yixuan He, Jingnan Li, Haowen Ma, Junhui Yao, Ying Zhao, Xinke Wang, Bin Hu, Yan Zhang, Juan Liu","doi":"10.1002/lpor.72099","DOIUrl":"https://doi.org/10.1002/lpor.72099","url":null,"abstract":"Perfect vortex beams (PVBs) carry valuable information in the intensity, phase, and polarization dimensions, offering powerful tools for optical communication, particle manipulation, and information encryption. Combining PVBs with a metasurface platform opens an avenue for multidimensional, high‐capacity, and secure optical encryption. However, precise control of the encoded dimensions and channels remains challenging. Here, we propose an optical encryption strategy based on a metasurface‐generated PVB array with four independent encryption dimensions and 441 parallel spatial channels. These dimensions, including PVB diameter, topological charge (TC) magnitude, TC sign, and polarization state, are mutually independent, significantly increasing the information capacity. In particular, the two phase‐related dimensions enhance encryption security because they cannot be directly measured by conventional CCDs. As a proof of concept, we develop a metasurface encryption system with high information capacity and improved security in the terahertz band. Four different QR codes are encrypted in a single metasurface device and can be decrypted only with the correct keys. By using each PVB as a basic information unit, the system becomes more controllable and robust. This work provides a strategy for high‐capacity and secure optical encryption, paving the way toward multidimensional photonic devices for encryption, data storage, and optical communication.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"13 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broadband Optical Characterization of Tetragonal Barium Titanate by Mueller-Matrix Spectroscopic Ellipsometry","authors":"Jiwon Kang,Nina Hong,Christopher M. Yi,Yun Su Go,Martin Thomaschewski,Hwi Je Woo,Prachi Thureja,Junghoon Jahng,Harry A. Atwater,Min Seok Jang","doi":"10.1021/acsphotonics.6c01514","DOIUrl":"https://doi.org/10.1021/acsphotonics.6c01514","url":null,"abstract":"Barium titanate (BTO), one of the earliest reported ferroelectric materials, exhibits strong second-order nonlinearity and an ultrafast Pockels effect, making it highly attractive for photonics. However, its optical constants remain uncertain largely due to the ubiquitous ferroelectric–ferroelastic multidomain microstructure, which depolarizes and averages out the anisotropic optical response, thereby complicating conventional ellipsometric approaches. Here, we report a Kramers–Kronig-consistent complex refractive-index tensor of tetragonal BTO from the ultraviolet (190 nm) to the far-infrared (40 μm) derived from multimodal Mueller-matrix spectroscopic ellipsometry. We further quantify optical loss by incorporating transmission intensity measured over the 2–10 μm transparency window, resolving the extinction coefficient down to ∼10–5. To verify the underlying domain configuration, we performed independent structural analyses, including electron backscatter diffraction, confocal Raman microscopy, and Kelvin probe force microscopy. We then reconstruct an effective optical model for our multidomain BTO sample, formulated as a mixture of three tetragonal variants with the determined intrinsic refractive indices, to link microscopic domains to the macroscopic optical response. Our work presents a unified, experimentally cross-validated data set, enabling accurate modeling for electro-optic modulators and high-Q nanophotonic resonators without ad hoc approximations, and provides a general strategy for optical metrology of complex ferroic crystals.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"56 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymptotically good bosonic Fock state codes","authors":"Dor Elimelech, Arda Aydin, Alexander Barg","doi":"10.22331/q-2026-10-20-2240","DOIUrl":"https://doi.org/10.22331/q-2026-10-20-2240","url":null,"abstract":"We study the error-correction properties of multi-mode Fock-state codes under amplitude-damping (AD) noise, focusing on the asymptotic regime in which the total excitation of the code states grows without limit and the number of photon losses induced by the noise scales linearly with it. In this setting, existing code families, which correct only sublinearly many photon losses, do not protect against amplitude-damping (AD) noise with a constant loss parameter. As our main result, we address this gap by constructing asymptotically good Fock-state codes relying on random classical codes in the discrete simplex. Unlike many standard constructions of random quantum codes, our construction introduces randomness through the underlying classical indexing structure. Randomization also enables another desirable feature: bounded per-mode occupancy, which limits the number of photons in any individual mode and thereby increases the coherence lifetime of the code states. Finally, via a relation between Fock-state codes and permutation-invariant codes, our results also yield asymptotically good families of qudit permutation-invariant codes as well as codes in monolithic nuclear state spaces.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"46 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}