Science Daily January 22, 2021 An international team of researchers (Australia, France) combined phase stabilisation technology with advanced self-guiding optical terminals that allowed laser signals to be sent from one point to another without interference from the atmosphere. They demonstrated phase-stabilized optical frequency transfer over a 265 m horizontal point-to-point free-space link between optical terminals with active tip-tilt mirrors to suppress beam wander, in a compact, human-portable set-up. They could correct for atmospheric turbulence in 3D, that is, left-right, up-down and, critically, along the line of flight. According to the researchers if you have one of these optical terminals on the […]
Tag Archives: optical communication
Ultra-fast polymer modulators that can take the heat
Science Daily November 13, 2020 Researchers in Japan took advantage of the high electro-optic activities, low dielectric constant, low propagation loss and ultra-high glass transition temperature of the developed side-chain electro-optic polymers to fabricate silicon-polymer hybrid modulator. It supports ultra-fast single-lane data rates up to 200 gigabits per second, excellent reliability, and exceptional signal fidelity at extremely high ambient temperatures up to 110 °C even after long-term exposure to high temperatures. It could provide ultra-fast and reliable interconnects for datacenters, 5G/B5G, autonomous driving, and aviation systems, effectively addressing the energy consumption issue for the next-generation optical communication…read more. Open Access TECHNICAL […]
New devices produce and detect twisted light
Physics World May 19, 2020 Development of a dynamically tunable OAM light source is a critical step in the realization of OAM modulation and multiplexing. An international team of researchers (USA – University of Pennsylvania, Northeastern University, Italy, Spain) harnessed the properties of total momentum conservation, spin-orbit interaction, and optical non-Hermitian symmetry breaking, demonstrated an OAM-tunable vortex microlaser, providing chiral light states of variable topological charges at a single telecommunication wavelength. The scheme can be further scaled up for simultaneous multivortex emissions in a flexible manner. The work provides a route for the development of the next generation of multidimensional […]
A perovskite-based diode capable of both light emission and detection
Phys.org April 10, 2020 An international team of researchers (Sweden, China, Italy, Switzerland) has developed an efficient solution-processed perovskite diode that can work in both emission and detection modes. The device can be switched between modes by changing the bias direction, and it exhibits light emission with an external quantum efficiency of over 21% and a light detection limit on a subpicowatt scale. The operation speed for both functions can reach tens of megahertz. The diodes exhibit a high specific detectivity at its peak emission (~804 nm), which allows an optical signal exchange between two identical diodes. To illustrate the potential […]
Team develops optical communications technology to double data transfer speed
Phys.org February 24, 2020 Researchers in South Korea have designed real-time pulse amplitude modulation-4 (PAM-4) digital signal processing including forward error correction for a C-band inter-datacenter network. The PAM-4 DSP is intended to compensate for chromatic dispersion and provide dispersion tolerance. A decision feedback equalizer and maximum likelihood sequence equalizer were employed for the dispersion compensation. A low-density parity check code was used to increase coding gain. They have empirically proved the feasibility of 25 km transmission without error-floor sign, corresponding to a dispersion compensation capacity of 425 ps/nm and confirmed 35 km ∼ 85 km error-free transmission for inter-datacenter […]
Researchers turn off backscattering, aim to improve optical data transmission
Nanowerk August 12, 2019 The most common manifestation of subwavelength disorder is Rayleigh light scattering, which is observed in nearly all waveguiding technologies today and can lead to both irreversible radiative losses as well as undesirable intermodal coupling. A team of researchers in the US (University of Illinois, University of Maryland, NIST) has demonstrated an optomechanical approach for dynamically suppressing Rayleigh backscattering within dielectric resonators by locally breaking the time-reversal symmetry in a silica resonator through a Brillouin scattering interaction that is available in all materials. They confirmed complete suppression of Rayleigh backscattering in their experiment through two independent measurements—the […]
Multicolored light twists in new knotted ways
Phys.org June 10, 2019 An international team of researchers (Spain, Austria, USA- University of Colorado) has designed a beam of light with a polarization state that forms three-lobed trefoils at each point by combining light of different frequencies (w and 2w), and making the trefoils connect to each other in a way such that the light beam, as a whole, has the shape of a knot. They found new conservation laws for non-linear optics which hold even in extreme situations where tens or hundreds of photons get combined to form single high-frequency photons and a new optical singularity, robust against […]
Virtually energy-free superfast computing invented by scientists using light pulses
Science Daily May 15, 2019 An international team of researchers (Germany, USA- UC Santa Barbara, Russia, the Netherlands) utilized the efficient interaction mechanism of coupling between spins and terahertz electric field, which was discovered by the same team. They developed and fabricated a very small antenna on top of the magnet to concentrate and thereby enhance the electric field of light. This strongest local electric field was sufficient to navigate the magnetization of the magnet to its new orientation in just one trillionth of a second without increasing the temperature. Future storage devices would also exploit the excellent spatial definition […]
Researchers take a step towards light-based, brain-like computing chip
Nanowerk May 8, 2019 Unlike real neural tissue, traditional computing architectures physically separate the core computing functions of memory and processing, making fast, efficient and low-energy computing difficult to achieve. An international team of researchers (Germany, UK) present an all-optical version of a neurosynaptic system, capable of supervised and unsupervised learning. They exploit wavelength division multiplexing techniques to implement a scalable circuit architecture for photonic neural networks, successfully demonstrating pattern recognition directly in the optical domain. Such photonic neurosynaptic networks promise access to the high speed and high bandwidth inherent to optical systems, thus enabling the direct processing of optical […]
Advancing undersea optical communications
MIT News August 17, 2018 The laser beams are hampered by significant absorption and scattering in the ocean. Researchers at MIT Lincoln Laboratory are applying narrow-beam laser technology, developed by the Laboratory for the LLCD (Lunar Laser Communication Demonstration), to enable communications between underwater vehicles. A beam from one underwater vehicle is pointed at the receive terminal of a second underwater vehicle. The position calculation is noise sensitive and can quickly accumulate errors of hundreds of meters when a vehicle is submerged for significant periods of time. To overcome this, they implemented an acquisition scanning function that is used to […]