Coming to a Lab Bench Near You: Femtosecond X-Ray Spectroscopy

Upon light activation (in purple, bottom row’s ball-and-stick diagram), the cyclic structure of the 1,3-cyclohexadiene molecule rapidly unravels into a near-linear shape in just 200 femtoseconds. Using ultrafast X-ray spectroscopy, researchers have captured in real time the accompanying transformation of the molecule’s outer electron “clouds” (in yellow and teal, top row’s sphere diagram) as the structure unfurls. (Credit: Kristina Chang/Berkeley Lab)

The ephemeral electron movements in a transient state of a reaction important in biochemical and optoelectronic processes have been captured and, for the first time, directly characterized using ultrafast X-ray spectroscopy at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). Like many rearrangements of molecular structures, the ring-opening reactions in this study occur on timescales of hundreds of femtoseconds (1 femtosecond equals a millionth of a billionth of a second). The researchers were able to collect snapshots of the electronic structure during the reaction by using femtosecond pulses of X-ray light on a tabletop apparatus.

Posted in: News, Lasers & Laser Systems, Optics, Photonics, Measuring Instruments, Test & Measurement

Engineers Invent Method to Control Light Propagation in Waveguides

Artistic illustration of a photonic integrated device. In one arm an incident fundamental waveguide mode (with one lobe in the waveguide cross-section) is converted into the second-order mode (with two lobes in the waveguide cross-section). In the other arm the incident fundamental waveguide mode is converted into strong surface waves. (Illustration courtesy of Adam Overvig and Nanfang Yu)

A team of Columbia Engineering researchers, led by Applied Physics Assistant Professor Nanfang Yu, has invented a method to control light propagating in confined pathways, or waveguides, with high efficiency by using nano-antennas. To demonstrate this technique, they built photonic integrated devices that not only had record-small footprints but were also able to maintain optimal performance over an unprecedented broad wavelength range.

Posted in: News, Nanotechnology, Optical Components, Optics, Photonics

Need Glass? Push Print.

LLNL researchers have reported the synthesis of 3D printed transparent glass components using a "slurry" of silica particles extruded through a direct-ink writing process. From left: LLNL chemical engineer and project lead Rebecca Dylla-Spears and LLNL materials engineer Du Nguyen.

Lawrence Livermore National Laboratory scientists and academic collaborators from the University of Minnesota and Oklahoma State University have demonstrated the synthesis of transparent glass through 3D printing, a development that could ultimately lead to altering the design and structure of lasers and other devices that incorporate optics.

Posted in: News, Lasers & Laser Systems, Optical Components, Optics

Using Sensor Fusion to Analyze Laser Processing in Additive Manufacturing

Sensor: “A device that detects or measures a physical property and records, indicates, or otherwise responds to it.” A sensor is a device that detects a physical quantity and responds by transmitting a signal.

Posted in: Articles, Imaging, Manufacturing & Prototyping, Lasers & Laser Systems, Photonics, Lasers, Sensors and actuators, Additive manufacturing

Development of Sodium Lidar for Spaceborne Missions

The metal layers at mesospheric altitudes are excellent tracers of neutral atmosphere dynamics, and have been used since the 1960s to study the chemistry and dynamics of the mesosphere. Ablation from meteors is believed to be the chief source of metals such as Na, Mg, K, Fe, and Ca in the middle atmosphere. Due to its relative abundance, large backscatter cross-section, and visible atomic transition, sodium (Na) has been used extensively for lidar studies of the mesosphere.

Posted in: Briefs, Photonics, Lidar, Weather and climate, Metals, Sodium, Test procedures

Bringing New Vision to Laser Material Processing Systems

The use of modern laser technology has become standard in industrial manufacturing thanks to its speed, accuracy and effectiveness. Lasers are used to engrave parts, electronic printed circuit boards or chip cards. They perforate packaging; structure semiconductor wafers; drill, cut and weld plastics or metals; and create highly complex structures via 3D printing.

Posted in: Articles, Imaging, Machine Vision, Lasers & Laser Systems, Photonics, Lasers, Additive manufacturing, Manufacturing equipment and machinery

Additive-Manufactured, Very Lightweight, Diamond Turned Aspheric Mirror

Industrial-grade, lightweight mirrors used in military and aeronautics have tight specifications brought on by demanding performance parameters. For example, a mirror that is used in an orbiting telescope would have to be extremely lightweight, stiff, and be configured to operate in extreme temperatures. These parameters traditionally work against each other. A material that is stiff is typically heavy, and a mirror that is lightweight and machinable may greatly distort when exposed to extreme heat or cold. Furthermore, materials that fit some of these parameters may not be easily machined to create a mirror, an art that requires high-precision tooling.

Posted in: Briefs, Photonics, Mirrors, Additive manufacturing, Lightweight materials

Choosing a Light and Color Measurement System for LEDs

LED-based lighting and display systems are becoming increasingly popular due to their low cost, flexibility, and efficiency. Measuring the light and color output of LEDs is, therefore, becoming more important as their performance is compared to and evaluated against traditional technologies. In addition, inherent performance variations from device to device must be understood and controlled.

Posted in: Application Briefs, Imaging, LEDs, Lighting, Photonics, Measurements, Light emitting diodes (LEDs), Performance tests

3D Imaging Reveals Sub-surface Battery Flaws

Ed Barnard

Traditional imaging technologies have been used to investigate overall solar efficiency, but many of the methods only offer surface views. A new – and “exciting” – ultra-fast laser technique developed at the Department of Energy's Lawrence Berkeley National Laboratory provides a deeper look and maps a solar cell in three dimensions.

Posted in: Articles, Imaging, Photonics, Batteries, Imaging and visualization, Lasers, Solar energy, Performance tests

Autonomous Vehicles Open Up New Roads for LIDAR Growth

Laser range-finding, or LIDAR, is a way of measuring distance, directly analogous to radar except using radiation in the near infrared range of the electromagnetic spectrum rather than the radio waves used in radar. LIDAR techniques are used for a variety of final applications including terrain-mapping for geology, urban planning and archaeology; distance measurement for surveying, golf, hunting, military applications, and docking of large ships; and speed measurement for traffic monitoring and speed limit enforcement.

Posted in: Articles, Imaging, Lasers & Laser Systems, Photonics, Measurements, Lidar, Autonomous vehicles

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.