Using laser-sourced light beams rather than wireless RF to link spacecraft with Earth offers the possibility of a significant increase in data rates. Still, there are significant technical challenges to the concept. Scientists, engineers, and researchers communicating with spacecraft have a problem: there’s so much data coming from these spacecraft – and to send to […]
optoelectronics
Free-space optical links, Part 2: Technical issues
Free-space optical links provide a reliable, cost-effective, and quick way to link two fixed communication nodes located a few kilometers apart. The first part of this article established the basic operating principles and rationale for free-space optical links. This part looks at some practical issues associated with their implementation. Q: How do you aim the […]
Free-space optical links, Part 1: principles
Free-space optical links provide a reliable, cost-effective, and quick way to link two fixed communication nodes located a few kilometers apart. When engineers think of “optical data links” or “optical communications” they almost invariably think of light (visible or not) in an optical fiber carrying data at high rates for tens or even thousands of […]
Optical tweezers move nano-objects, Part 3: The system
Part 2 of this article continued the exploration of the basic optical tweezer. This part builds up to a complete system, DIY optical tweezer systems, and extensions to the basic optical-tweezer arrangement. The optical tweezer is obviously not a simple system, and a complete system requires lenses, dichroic mirrors, a laser, video camera, isolation against […]
Optical tweezers move nano-objects, Part 2: The optical path
A combination of optics, lasers, electronics, and combined with advanced physics principles, allows “touch-free” physical manipulation of molecules, viruses, and other nano-sized objects. Part 1 of this article presented the goals of the optical-tweezer design and some of the reasoning which leads to it. This part continues to build up to a larger, complete system. […]
Optical tweezers move nano-objects, Part 1: The Principles
A combination of optics, lasers, electronics, and combined with advanced physics principles, allows “touch-free” physical manipulation of molecules, viruses, and other nano-sized objects. How do you manipulate and move tiny objects such as pieces of DNA or living cells? Conventional mechanical or vacuum tweezers, no matter how small, couldn’t grab them and would cause damage […]
Lasers, optics, electronics and more yield terahertz sources, Part 1 – Context
The terahertz part of the electromagnetic spectrum between millimeter waves and optical range remains a largely untapped, difficult-to-use resource; researchers are investigating different techniques for efficiently generating terahertz waves to promote the use of this part of the spectrum. Electromagnetic energy in the terahertz (THz) region of the spectrum, nominally 300 GHz/0.3 THz to 10 […]
InGaAs PIN photodiodes available in 2.0 mm and 3.0 mm gain area sizes
Marktech Optoelectronics, Inc. announced the global market introduction of the Models MTPD1346D-200 and MTPD1346D-300, two unique large active area InGaAs PIN photodiodes, expressly designed for expanded infrared instrumentation and monitoring capabilities. Marktech’s new Models MTPD1346D-200 and MTPD1346D-300 are available in higher-gain active area sizes of 2.0 mm and 3.0 mm, respectively, joining existing series InGaAs […]
Photodiode: light sources, the amount of light, and color
I have touched on light sensing methods and the amplification of the signals from them in the past, but at a more fundamental level, how do you choose one? What parameters are important? The answer depends, among other things, on the light source (focused or not), the amount of light and its color. Focused or […]
Fiber-optic pump combiners boost laser output
LASER COMPONENTS has extended its product range with fiber-optic pump combiners by Lightel. With these passive components, pump signals of up to 36 laser sources can be bundled to achieve higher exit powers in high-energy fiber lasers. This special air-clad technology from Lightel allows power input coupling with efficiencies of 90% or higher. Depending on […]
