Nozaki, K., Shinya, A., Matsuo, S., Suzaki, Y., Segawa, T., Sato, T., et al. (2012). Ultralow-power all-optical RAM based on nanocavities. Nat. Photon., 6(4), 248–252.
Abstract: Optical random-access memory (o-RAM) has been regarded as one of the most difficult challenges in terms of replacing its various functionalities in electronic circuitry with their photonic counterparts. Nevertheless, it constitutes a key device in optical routing and processing. Here, we demonstrate that photonic crystal nanocavities with an ultrasmall buried heterostructure design can solve most of the problems encountered in previous o-RAMs. By taking advantage of the strong confinement of photons and carriers and allowing heat to escape efficiently, we have realized all-optical RAMs with a power consumption of only 30 nW, which is more than 300 times lower than the previous record, and have achieved continuous operation. We have also demonstrated their feasibility in multibit integration. This paves the way for constructing a low-power large-scale o-RAM system that can handle high-bit-rate optical signals.
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Pris, A. D., Utturkar, Y., Surman, C., Morris, W. G., Vert, A., Zalyubovskiy, S., et al. (2012). Towards high-speed imaging of infrared photons with bio-inspired nanoarchitectures. Nat. Photon., 6(3), 195–200.
Abstract: Existing infrared detectors rely on complex microfabrication and thermal management methods. Here, we report an attractive platform of low-thermal-mass resonators inspired by the architectures of iridescent Morpho butterfly scales. In these resonators, the optical cavity is modulated by its thermal expansion and refractive index change, resulting in `wavelength conversion' of mid-wave infrared (3-8 µm) radiation into visible iridescence changes. By doping Morpho butterfly scales with single-walled carbon nanotubes, we achieved mid-wave infrared detection with 18-62 mK noise-equivalent temperature difference and 35-40 Hz heat-sink-free response speed. The nanoscale pitch and the extremely small thermal mass of individual `pixels' promise significant improvements over existing detectors. Computational analysis explains the origin of this thermal response and guides future conceptually new bio-inspired thermal imaging sensor designs.
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Akalin, T. (2012). Terahertz sources: Powerful photomixers. Nat. Photon., 6(2), 81.
Abstract: An efficient continuous-wave source of terahertz radiation that combines the outputs from two near-infrared semiconductor lasers in a novel photomixer looks set to benefit applications in spectroscopy and imaging.
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Williams, B. S. (2007). Terahertz quantum-cascade lasers. Nature Photonics, 1, 517–525.
Abstract: Six years after their birth, terahertz quantum-cascade lasers can now deliver milliwatts or more of continuous-wave coherent radiation throughout the terahertz range — the spectral regime between millimetre and infrared wavelengths, which has long resisted development. This paper reviews the state-of-the-art and future prospects for these lasers, including efforts to increase their operating temperatures, deliver higher output powers and emit longer wavelengths.
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Paiella, R. (2011). Terahertz quantum cascade lasers: Going ultrafast. Nat. Photon., 5, 253–255.
Abstract: A new asynchronous coherent optical sampling method allows for the direct visualization of actively mode-locked quantum cascade laser pulses at terahertz wavelengths.
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