Arrays of photodetector-based pixel sensors are ubiquitous in modern devices, such as smart phone cameras, automobiles, drones, laptops etc. Two-dimensional (2D) material-based photodetector arrays are a relevant candidate, especially for applications demanding planar form factors. However, shortcomings in pixel density and prototyping without cross contamination limit technology adoption and impact. Also, while 2D material detectors offer high absorption, graphene's closed bandgap results in undesirably high dark currents. Here, we introduce the experimental demonstration of dense planar photodetector arrays. We demonstrate a micrometer-narrow pitched 2D detector pixels and show this approach's repeatability by verifying performing of a 16-pixel detector array. Such dense and repeatable detector realization is enabled by a novel, selective, contamination-free 2D material transfer system, that we report here in automated operation. The so realized photodetectors responsivity peaks at a high 0.8 A/W. Furthermore, we achieve uniform detector performance via bias voltage tuning calibration to maximize deployment. Lastly, we demonstrate 2D arrayed photodetectors not only on a silicon chip platform but verify array performance on flexible polymer substrates. Densley-arrayed, flat, bendable, and uniform performing photodetector pixels enable emerging technologies in the space where lightweight and reliable performance is required, such as for the smart phone and emerging VR/AR markets, but also for smart gadgets, wearables, and also for size-weight-power-constrained aviation and space platforms.
", "doi": "10.1515/nanoph-2025-0048", "issn": "2192-8606", "publisher": "Walter de Gruyter GmbH", "publication": "Nanophotonics", "publication_date": "2025-11-02", "series_number": "23", "volume": "14", "issue": "23", "pages": "4197-4205" }, { "id": "authors:0yb8a-j1c71", "collection": "authors", "collection_id": "0yb8a-j1c71", "cite_using_url": "https://authors.library.caltech.edu/records/0yb8a-j1c71", "type": "article", "title": "Plasmonic electro-optic modulators on lead zirconate titanate platform", "author": [ { "family_name": "Yezekyan", "given_name": "Torgom", "orcid": "0000-0003-2019-2225" }, { "family_name": "Thomaschewski", "given_name": "Martin", "orcid": "0000-0003-2545-1468", "clpid": "Thomaschewski-Martin" }, { "family_name": "Thrane", "given_name": "Paul Conrad Vaagen", "orcid": "0000-0001-5296-2912" }, { "family_name": "Bozhevolnyi", "given_name": "Sergey I.", "orcid": "0000-0002-0393-4859" } ], "abstract": "The advancement in material platforms exhibiting strong and robust electro-optic effects is crucial for further progress in developing highly efficient and miniaturized optoelectronic components with low power consumption for modern optical communication systems. In this work, we investigate thin-film lead zirconate titanate (PZT) substrates grown by a chemical solution deposition technique as a potential platform for on-chip plasmonic electro-optic modulators. A high modulation depth (>40\u202f%) is achieved with 15\u202fμm-long electro-optic directional coupler modulators. An unusual cutoff in the modulation frequency response at ∼200\u202fkHz is observed and further studied with respect to possible reorientation effects. Second-harmonic generation signals are found influenced by the externally applied electric field, indicating that the domain reorientation effect can be responsible for the unusual frequency response observed.
", "doi": "10.1515/nanoph-2024-0039", "issn": "2192-8614", "publisher": "Walter de Gruyter GmbH", "publication": "Nanophotonics", "publication_date": "2024-08", "series_number": "18", "volume": "13", "issue": "18", "pages": "3591-3598" }, { "id": "authors:9qjeg-j7779", "collection": "authors", "collection_id": "9qjeg-j7779", "cite_using_url": "https://authors.library.caltech.edu/records/9qjeg-j7779", "type": "article", "title": "Near-Field Observation of the Photonic Spin Hall Effect", "author": [ { "family_name": "Thomaschewski", "given_name": "Martin", "orcid": "0000-0003-2545-1468", "clpid": "Thomaschewski-Martin" }, { "family_name": "Pr\u00e4massing", "given_name": "Mike", "orcid": "0000-0002-5145-864X", "clpid": "Pr\u00e4massing-Mike" }, { "family_name": "Schill", "given_name": "Hans-Joachim", "clpid": "Schill-Hans-Joachim" }, { "family_name": "Zenin", "given_name": "Vladimir A.", "orcid": "0000-0001-5512-8288", "clpid": "Zenin-Vladimir-A" }, { "family_name": "Bozhevolnyi", "given_name": "Sergey I.", "orcid": "0000-0002-0393-4859", "clpid": "Bozhevolnyi-Sergey-I" }, { "family_name": "Sorger", "given_name": "Volker J.", "orcid": "0000-0002-5152-4766", "clpid": "Sorger-Volker-J" }, { "family_name": "Linden", "given_name": "Stefan", "orcid": "0000-0002-1028-9528", "clpid": "Linden-Stefan" } ], "abstract": "The photonic spin Hall effect, referring to the spatial separation of photons with opposite spins due to spin\u2013orbit interactions, has enabled potential for various spin-sensitive applications and devices. Here, using scattering-type near-field scanning optical microscopy, we observe spin\u2013orbit interactions introduced by a subwavelength semiring antenna integrated in a plasmonic circuit. Clear evidence of unidirectional excitation of surface plasmon polaritons is obtained by direct comparison of the amplitude- and phase-resolved near-field maps of the plasmonic nanocircuit under excitation with photons of opposite spin states coupled to a plasmonic nanoantenna. We present details of the antenna design and experimental methods to investigate the spatial variation of complex electromagnetic fields in a spin-sensitive plasmonic circuit. The reported findings offer valuable insights into the generation, characterization, and application of the photonic spin Hall effect in photonic integrated circuits for future and emerging spin-selective nanophotonic systems.
", "doi": "10.1021/acs.nanolett.3c02829", "issn": "1530-6984", "publisher": "American Chemical Society", "publication": "Nano Letters", "publication_date": "2023-11-20" } ]