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Chandrasekar, R., Lapin, Z. J., Nichols, A. S., Braun, R. M., & Fountain, A. W. (2019). Photonic integrated circuits for Department of Defense-relevant chemical and biological sensing applications: state-of-the-art and future outlooks. In Opt. Eng. (Vol. 58, 1).
Abstract: Photonic integrated circuits (PICs), the optical counterpart of traditional electronic integrated circuits, are paving the way toward truly portable and highly accurate biochemical sensors for Department of Defense (DoD)-relevant applications. We introduce the fundamentals of PIC-based biochemical sensing and describe common PIC sensor architectures developed to-date for single-identification and spectroscopic sensor classes. We discuss DoD investments in PIC research and summarize current challenges. We also provide future research directions likely required to realize widespread application of PIC-based biochemical sensors. These research directions include materials research to optimize sensor components for multiplexed sensing; engineering improvements to enhance the practicality of PIC-based devices for field use; and the use of synthetic biology techniques to design new selective receptors for chemical and biological agents.
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Kovaluyk, V., Lazarenko, P., Kozyukhin, S., An, P., Prokhodtsov, A., Goltsman, G., et al. (2019). Influence of the phase state of Ge2Sb2Te5 thin cover on the parameters of the optical waveguide structures. In Proc. Amorphous and Nanostructured Chalcogenides (pp. 47–48). Technical University of Moldova.
Abstract: The fast switching time of Ge-Sb-Te thin films between amorphous and crystalline states initiated by laser beam as well as significant change of their optical properties and the preservation of metastable states for tens of years open wide perspectives for the application of these materials to fully optical devices [1], including high-speed optical memory [2]. Here we study optical properties of the Ge2Sb2Te5 (GST225) thin films integrated with on-chip silicon nitride O-ring resonator. The rib waveguide of the resonator was formed the first stage of e-beam lithography and subsequent reactive-ion etching. We used the second stage of e-beam lithography combining with lift-off method for the formation of GST225 active region on the resonator ring surface. The amorphous GST225 thin films were prepared by magnetron sputtering, and were capped by thin silicon oxide on their tops. The length of the GST225 active region varied from 0.1 to 20 μ m. Crystallization of amorphous thin films was carried out at the temperature of 400 °C for 30 minutes. Auger electron spectroscopy and transmission electron microscopy were used for studying composition and structure of investigated GST225thin films, respectively. It was observed that crystallization of amorphous GST225 film lead to a decrease of the optical power, transmitted through the waveguide. Comparison of the optical transmittance of O-ring resonators before and after the GST225 deposition allowed to identify the change in the Q-factor and the wavelength peak shift. This can be explained by the differences of the complex refractive indexes of GST225 thin films in the amorphous and crystalline states. From the measurement data, the GST225 effective refractive index was extracted depending on the ring waveguide width of the resonator for a telecommunication wavelength of 1550 nm.
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Goltsman, G. (2017). Superconducting thin film as infrared heterodyne and direct detectors. In 16th ISEC (pp. 1–3).
Abstract: We present our recent achievements in the development of superconducting nanowire single-photon detectors (SNSPDs) integrated with optical waveguides on a chip. We demonstrate both single-photon counting with up to 90% on-chip-quantum-efficiency (OCDE), and the heterodyne mixing with a close to the quantum limit sensitivity at the telecommunication wavelength using single device.
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Kahl, O., Ferrari, S., Kovalyuk, V., Goltsman, G. N., Korneev, A., & Pernice, W. H. P. (2015). Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths. Sci. Rep., 5, 10941 (1 to 11).
Abstract: Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present efficiencies close to unity at 1550nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noiseequivalent powers in the 10–19W/Hz–1/2 range and the timing jitter is as low as 35ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms.
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Korneev, A., Golt'sman, G., & Pernice, W. (2015). Photonic integration meets single-photon detection (Vol. 51).
Abstract: By embedding superconducting nanowire single-photon detectors (SNSPDs) in nanophotonic circuits, these waveguide-integrated detectors are a key building block for future on-chip quantum computing applications.
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