Modelocked and Q-Switched Lasers for Materials Processing – Recently high-power, modelocked lasers in the ultraviolet spectral range, producing trains of picosecond pulses, have appeared in the commercial marketplace. In many cases, these lasers compete with Q-switched ultraviolet lasers that generate nanosecond pulses. Spectra-Physics markets both kinds of lasers, so the company has no ax to grind. In this article, they will compare results using these two lasers, and discuss guidelines as to which laser to use for optimal results, depending on material type and thickness.  

Cameras Update – This series of brief articles coordinated by Senior Editor Anne Fischer will provide an overview of how different cameras are being used to solve unique technical challenges: 

Self-Calibration and the Streak Camera – For many years, streak cameras have been the only way to make measurements of laser pulses on the order of a few picoseconds. However, they have been difficult to operate and required a team of experts as well as external illumination sources and optical equipment to calibrate and keep running. Researchers at the University of Rochester have developed a patented method for self-calibration using all internal components, eliminating much of the equipment required for external calibration lab support. This article from Sydor Instruments, describes the enhanced streak camera, which has a software interface for comprehensive image analysis and remote camera operation.  

Deep Depletion CCD Cameras – Over the last few years, scientific low-light imaging detectors arguably reached a performance plateau with greater than 90 percent quantum efficiency, less than 1 electron rms, and deep cooling of up to -120C. While these standard back-illuminated CCD and EMCCD cameras perform very well in the ultraviolet to visible regions, they have unique drawbacks such as etaloning. The deep depletion CCD technology not only eliminates the limitation, but also increases near-infrared sensitivity. This article from Princeton Instruments describes deep depletion technology in detail, and how it is enabling research in such disparate fields as astronomy, semiconductor failure analysis and Bose-Einstein condensate.  

Back Illuminating CCD and CMOS Imagers – In this article, experts from Sarnoff Corp. will describe a new solution for higher performance, lower cost CCD or CMOS imagers used in scientific and industrial inspection camera systems. The authors will show how incorporating Ultra Thin Silicon-on-Insulator (UTSOI) wafer technology coupled with back-illumination processes solves the cost-quality challenge to make higher performance back-thinned imagers available for mass production. 

Thermographic Technology – An IR camera module in combination with a special relay lens is used for measurement of the heat distribution inside a newly developed rocket engine for future Mars missions. The plasma technology used for the rocket engine involves high magnetic fields and vacuum environments, which set high physical demands on the IR camera. Accurate analysis of the thermal data from the rocket engine requires a high spatial resolution as well as high temperature resolution of the imager. This article describes the technology within IR-TCM 640 thermographic camera module from Jenoptik.  

Fiber Update – In this editor coordinated series, Senior Editor Anne Fischer will look at advancements in fiber technology. 

Fiber Laser Advancements – Tracing a history of almost 50 years, fiber lasers are in many respects a mature technology with commercially available systems now capable of delivering multi-kW, near diffraction limited, pulsed, and continuous wave outputs. These devices are used in a myriad of applications from high-power industrial material processing, tactical weapons and sensing devices, to marking, printing, and surgery. Interestingly, while fiber lasers have seen success in many areas, complications inherent to fiber design have rendered it a significantly inferior technology to its solid-state and gas laser alternatives for some applications. This article from Nufern looks at a number of significant advances in fiber design and glass composition, which have spawned a renewed and rapidly growing interest in this laser technology platform. 

Landslide Monitoring – Loose sediment, rocks, and weathered material usually remain stationary and stable on a slope. However, the material can be disturbed naturally by earthquakes or heavy rainfall, or by human activity, such as road construction. This article from Central Scientific Research Organization looks at ways of monitoring for landslides, and looks at a variety of tools including inclinometers, extensometers and tiltmeters. The author, however, introduces the fiber-optic interrogator based on optical time-domain reflectometry, a tool that can accurately and economically predict landslides.

An Overview of the 2008 PICALO Conference – Held for the first time in Beijing, the third annual PICALO Conference, April 16-18, featured reports on the newest trends and techniques in material processing and nanofabrication. Presenters from China, Europe, Japan, the U.S., and elsewhere discussed topics ranging from relativistic light-matter interactions to burning-stabilized laser cutting of stainless steel. In this article, Paradigm Laser Research will provide readers with an insight into many of the conference highlights.

Optical Coatings – Magnetron sputtering is already acknowledged to produce some of the highest quality optical thin films available, but current techniques are expensive, complex and not scalable. Existing technologies use an auxiliary ion/plasma source to convert metal into metal-oxide. Applied Multilayers Ltd. will write about a process known as “Closed Field” Reactive Magnetron Sputtering that overcomes some of the problems of other technologies. It produces very smooth coatings that are deposited at high rates. The simplicity of the process makes it suitable for batch, in-line or roll-to-roll coating. The technology can be used for applications that include thin film solar cells, flat panel displays, AR coatings, ophthalmic lens coatings, high brightness LEDs, and lighting filters. 

Showcase Themes:

• Cameras
• Optics & Optics Fabrication

Note: Article topics and trade shows are subject to change.

Bonus Distribution:

AUGUST/SEPTEMBER 2008 TECH BRIEFS