Fiber modem | Laser Focus World

Fiber modem

The TC1540 two-wire RS-485 fiber modem can mix or match RS-485 (using two or four wires), RS-232 or RS-422 interfaces. The device supports asynchronous data rates u¥to 700 kbit/s depending on the electrical interface, and is compatible with popular types and sizes of multimode and single mode fiber at 850, 1300, or 1550 nm.

TC Communications, Irvine, CA

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Femtosecond Applications Benefit from Ytterbium Amplifiers

Femtosecond Applications Benefit from Ytterbium Amplifiers

Learn how Monaco extends capabilities and enables new experiments in diverse fields such as THz microscopy, metal texturing, and multiphoton imaging.

FIGURE 1. The rubidium titanyl phosphate (RTP) Q-switch is assembled in a thermally compensated double-crystal configuration in which two matched crystals are placed in line with the propagation axis (x or y) with one crystal rotated by 90° with respect to the other.

Optical Materials: RTP optical crystal helps boost performance of LIGO

Upgrading the Laser Interferometer Gravitational-Wave Observatory (LIGO) included the addition of a rubidium titanyl phosphate (RTP) Q-switch to handle high optical powers.

Dr. Constantin Häfner.

Constantin Häfner named new director of Fraunhofer Institute for Laser Technology ILT

Effective November 2019, laser physicist Dr. Constantin Häfner will be taking on the Directorship of Fraunhofer ILT in Aachen, Germany. He is currently Program Director for Advanced Photon Technologies at LLNL in the U.S.

Lasers for lidar and more

Editor in chief John Lewis introduces Laser Focus World’s August 2019 issue, which includes trends in photonics technologies, applications, and markets.

Large-field cryogenic objective mirror has nearly diffraction-limited performance

Designed for use while being cooled by liquid helium, a cryogenic objective mirror with an aspherical surface has a NA of 0.93 and a field radius of 36 µm, large enough to image mammalian cells.

Shown are tuning curves for three quantum dots positioned on the waveguide at the locations shown in the inset, to achieve identical emission (a). High-resolution Fabry-Perot interferometer measurements show all three quantum dots simultaneously from an output coupler with identical emission wavelength (b).

Quantum Sources: Squeezed quantum dots create coherent streams of quantum-ready photons

By squeezing quantum dots using unique semiconductor-based processes, coherent single photons are generated that can be used for on-chip quantum photonics that demand identical photons from multiple integrated sources.

FIGURE 1. In the scalable setting of a spatial photonic Ising machine, binary spins are encoded in the phase of a laser beam (green) by spatial modulation. Tailoring of the beam’s amplitude fixes spin-spin interaction. To find the ground-state spin configuration, the machine recurrently evolves according to a feedback signal from the camera plane. By design, maximizing the intensity in a target region (blue square) corresponds to a spin state with minimum energy.

Photonics Modeling: Optical Ising machines solve complex engineering, science, and even business problems

Researchers have built the largest photonic Ising machine to date—an optical processor for solving difficult optimization problems by modeling interacting spins via a spatially varying light field.

To create a gold grating on a nanowire array (a), the nanowires themselves (vertical projections) were used as shadow masks by depositing the gold at an angle to the surface, resulting in undeposited areas (dark regions). Future nanowire-based separate absorption and multiplication avalanche photodiodes (SAM-APDs) will have faceted nanowires to help relieve lattice-mismatch strain (b).

Short- and mid-wavelength infrared nanowire photodiodes are uncooled

Nanowires of InAs and InAsSb on an indium phosphide substrate form room-temperature SWIR or MWIR photodiodes suitable for focal-plane arrays.

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Metasurface lens on diamond single-photon quantum source efficiently collects photons

A nitrogen-vacancy (NV) diamond produces single photons; a metalens etched into its surface collects them, no microscope needed.

On-chip laser-based quantum device generates true random numbers

A photonic integrated circuit containing two laser diodes whose outputs are interfered and measured produces truly random numbers at gigahertz rates.

Fiber sensing

FIGURE 1. The transparent zebrafish embryo enables paired patch clamp measurements of spinal neurons and locomotory muscle cells. Two chevron-shaped repetitive segments of tail muscle are shown. The two patch clamp recording electrodes are shown for an individual motoneuron and muscle cell. Only one electrode is visible in the field because placement of the electrodes during formation of whole-cell recording mode is done under very high magnification.

Neuroscience/Bioimaging: Optomechanics reveals transmitter roles in neuromuscular junctions

A clever optomechanical setup enables researchers to use patch clamp, Ca2+ imaging, and optogenetics to elucidate the roles of various neurotransmitters and correlate them with known genetic-defect diseases in humans.

A diagram shows NIST’s ion trap used for reversible “quantum squeezing” to amplify and measure ion motion. The ion (white ball) is confined 30 microns above the trap surface by voltages applied to the eight gold electrodes and the two red electrodes. Squeezing--that reduces the uncertainty of motion measurements--is achieved by applying a specific signal to the red electrodes. The ion is moved by applying another type of signal to one of the gold electrodes. Then the squeezing is reversed, and the blue electrodes generate magnetic fields used to decode the amplified motion measurements.

NIST quantum squeezing and amplification technique advances quantum computing

NIST’s rapid, reversible squeezing method could speed up operations in a quantum computer.

LASER World of PHOTONICS 2019: Inspiring

The depth and diversity of photonics technologies and products on display is an exciting reminder of the pivotal role of the world’s leading photonics tradeshow.