1,721,531 research outputs found
Dataset for Mid-infrared liquid spectroscopy using chalcogenide optical waveguide
No full textData to support:
Mittal, Vinita, Wilkinson, James and Ganapathy, Senthil (2016) Mid-infrared liquid spectroscopy using chalcogenide optical waveguide. EMN Photonics '16 Barcelona, ES, 19 - 23 Sep 2016.</span
Optical quality ZnSe films and low loss waveguides on Si substrates for mid-infrared applications
No full textData for the paper Mittal, Vinita, Sessions, Neil, Wilkinson, James and Ganapathy, Senthil (2017) Optical quality ZnSe films and low loss waveguides on Si substrates for mid-infrared applications. Optical Materials Expres, 7, (3), 712-725. (doi:10.1364/OME.7.000712).</span
Integrated photonic sensors for water pollution monitoring
No full textPhotonic technologies are set to revolutionise acquisition of chemical and biochemical information, driven by the demand for fast, low-cost, automated chemical analysis in a multiplicity of applications from point-of-care diagnostics to water quality monitoring. The integration, low cost and robustness of the microfabrication approaches which have made consumer electronics possible are enabling mass-produced chemical and bioanalytical microsystems. Optical techniques play a major role in quantitative chemical analysis and remain the mainstay of detection in “lab-on-chip” systems, but the degree of optical functionality integrated within these systems remains limited, and they have yet to benefit fully from the massive growth in optical telecommunications technologies in recent decades. Biosensor and lab-on-chip research and commercialisation have also been hampered by the lack of integrated photonic platforms which can operate over the mid-infrared (MIR) region from 2μm to 15μm, which would enable new opportunities for sensitive, selective, label-free biochemical analysis. Progress on new materials and approaches for high-sensitivity integrated photonic sensors for application in water and other aqueous media will be described
Lanthanide-doped photonic circuits
No full textSilicon photonic circuits exploit microelectronic processing technology to enable a revolution in mass-manufacture of photonic systems, building on the earlier revolution in electronic systems which enabled complex electronic functionality at low cost. To provide full photonic functionality, in terms of amplification, switching, filtering, all-optical processing, delay and storage, new fabrication processes and new CMOS compatible complementary materials systems must be developed. Silicon dioxide is ideal for many photonic applications but its small nonlinearity, low refractive index, poor lanthanide solubility and limited IR transmission precludes its application to high-density all-optical circuits or new wavelength windows. Silicon itself has exhibited remarkable performance for compact linear and nonlinear optical devices and while waveguiding in silicon is attractive at wavelengths beyond 1.1μm, the use of Si3N4 for optical parametric oscillators [1] has emphasised that silicon does not meet every need. More recently, lanthanide-doped Al2O3 has been combined with Si3N4 waveguides on silicon as an alternative route to providing gain in Si/Si3N4 photonic circuits [2]. Tantalum pentoxide (Ta2O5) is an alternative CMOS-compatible waveguide material and several important properties and functions for high-density photonic circuits have been demonstrated. These include suitability as a host for rare-earth ions, with amplification and lasing demonstrated at 1.5μm [3] and 1.02μm [4] for example, and third-order nonlinearity at least 30 times that of silica [5,6]. Ta2O5 has a large bandgap (4-2 – 5.2 eV) so that, at a conservative estimate, two-photon absorption (TPA) is not evident for wavelengths longer than 700nm, while in the case of Si, TPA is significant at wavelengths below 2.25μm. The CMOS compatibility of these materials allows combination in a multilayer configuration with silicon photonics to offer complementary functionality within silicon photonic circuits. Ta2O5 exhibits good transmission at wavelengths between 350nm and 8μm, opening up the potential for mid-infrared devices. Progress in lanthanide-doped CMOS compatible photonic circuits will be reviewed and recent results discussed.References1 J.S. Levy et al., “CMOS-compatible multiple-wavelength oscillator for on-chip optical interconnects”, Nat. Photon., 4, 37-40 (2010).2 Purnawirman et al., “Ultra-narrow-linewidth Al2O3:Er3+ lasers with a wavelength-insensitive waveguide design on a wafer-scale silicon nitride platform”, Opt. Express, 25, 13705-13713 (2017). 3 A.Z. Subramanian et al., “Erbium-doped waveguide laser in tantalum pentoxide”, IEEE Photon. Technol. Lett., 22, 1571-1573 (2010).4 A. Aghajani et al., “Waveguide lasers in ytterbium-doped tantalum pentoxide on silicon”, Opt. Lett., 40, 2549-2552 (2015).5 C.-Y. Tai et al., “Determination of nonlinear refractive index in a Ta2O5 rib waveguide using self-phase modulation”, Opt. Express 12, 5110-5116 (2004).6 C. Lacava et al., “Nonlinear optical properties of ytterbium-doped tantalum pentoxide rib waveguides on silicon at telecom wavelengths”, Optical Fiber Communications Conference (ECOC), Anaheim, CA, Mar 20-24, 2016.<br/
Integrated photonic sensors for water pollution monitoring
No full textPhotonic technologies are set to revolutionise acquisition of chemical and biochemical information, driven by the demand for fast, low-cost, automated chemical analysis in a multiplicity of applications from point-of-care diagnostics to water quality monitoring. The integration, low cost and robustness of the microfabrication approaches which have made consumer electronics possible are enabling mass-produced chemical and bioanalytical microsystems. Optical techniques play a major role in quantitative chemical analysis and remain the mainstay of detection in “lab-on-chip” systems, but the degree of optical functionality integrated within these systems remains limited, and they have yet to benefit fully from the massive growth in optical telecommunications technologies in recent decades. Biosensor and lab-on-chip research and commercialisation have also been hampered by the lack of integrated photonic platforms which can operate over the mid-infrared (MIR) region from 2μm to 15μm, which would enable new opportunities for sensitive, selective, label-free biochemical analysis. Progress on new materials and approaches for high-sensitivity integrated photonic sensors for application in water and other aqueous media will be described
Planar lightwave platforms for bio- and chemical sensing
No full textSimple planar waveguides are well established components for the optical interrogation of chemical processes at surfaces, with total internal reflection fluorescence (TIRF) elements having a long pedigree and surface plasmon resonance (SPR) sensors finding widespread use in biomolecular research, for example. Key attributes of these devices are that the optical fields are confined to a submicrometer region above the solid surface of the transducer and that the light is delivered to the surface in a well-controlled way without passing through the bulk of the sample
Integrated photonics in CMOS-compatible dielectric platforms
No full textPlanar processing technology enables great complexity at low cost for electronic systems and now has the potential to provide a revolution in mass-manufacture for all-optical systems. For this to be realised, new materials and fabrication processes suitable for advanced photonic applications must be devised. Silica is ideal for many photonics applications but its small nonlinearity, low refractive index, poor rare-earth solubility and limited IR transmission precludes its application to high-density all-optical circuits or new wavelength windows. Silicon has exhibited remarkable performance for compact linear and nonlinear optical devices and while waveguiding in silicon is attractive at wavelengths beyond 1.1µm, the recent use of Si3N4 for optical parametric oscillators [J.S. Levy et al., Nat. Photon., 4, 37-40 (2010)] has emphasised that silicon does not meet every need. Tantalum pentoxide (Ta2O5) is an alternative CMOS-compatible waveguide material and in recent years several important properties and functions for high-density photonic circuits have been demonstrated. These include suitability as a host for rare-earth ions with amplification and lasing at 1.5µm [A.Z. Subramanian et al., IEEE Photon. Technol. Lett., 22, 1571-1573 (2010)] and third-order nonlinearity 30 times that of silica at 1.5µm [C.-Y. Tai et al., Opt. Exp. 12, 5110-5116 (2004)]. Ta2O5 has a large bandgap (4-2 – 5.2 eV) so that, at a conservative estimate, two-photon absorption (TPA) is not evident for wavelengths beyond 700nm, while in the case of Si, TPA is significant at wavelengths below 2.25µm; Ta2O5 also exhibits good transmission at wavelengths between 350nm and 8µm. For many short-pulse interactions, precise control of group velocity dispersion is needed, and waveguide engineering in high index materials such as Si3N4 and Ta2O5 allows this. The CMOS compatibility of these materials allows combination in a multilayer configuration with silicon photonics to offer additional functionality to silicon photonic circuits
Integrated optical chemical sensing
No full textIntegrated optical techniques offer the potential for miniature, low-cost, reliable microsystems for chemical analysis which may be exploited in monitoring environmental pollution, food contamination, state of health, and threats to security. Some approaches towards providing flexible multisensor platforms for a wide variety of chemical and biochemical species will be presented
BIOPTICAS: optical biosensing techniques for monitoring organic pollutants in the aquatic environment
No full textThe BIOPTICAS project aims to develop optically-based analytical techniques for the detection and measurement of low concentrations of organic pollutants in the aquatic environment. Two basic types of measurement systems are being developed. Low cost, fast, and highly sensitive immunoassay-based assay kits for use by water monitoring authorities for pesticide-level monitoring and, thin film and integrated optical-based technologies that provide opportunities to develop semi- or fully automated sensing systems for pollution monitoring. Although these systems are directed primarily towards pesticide detection, it is foreseen that far wider applications for diagnostics and monitoring can be addressed by the technologies developed by this project
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