Though not yet running at full capacity, the National Ignition Facility at Lawrence Livermore National Laboratory (Livermore, CA) is now operational. It has taken 15 years and $3.5 billion to build the huge 192-beam laser system, which is now on a gradual ramp toward its full design output of 1.8 MJ of ultraviolet pulse energy. All being well, the laser will achieve ignition by 2012 (the interior of the NIF target chamber is featured on this month’s cover). The ultimate success of NIF will depend among other things on the materials science around its optics—with energy densities of up to 8 J/cm2, optical damage has been problematic and remains a concern (see Photonic Frontiers).
You can find out more about NIF and its future at the 2010 Lasers & Photonics Marketplace Seminar. In his keynote presentation, “Bringing Star Power to Earth,” astronaut Dr. Jeff Wisoff will describe NIF, the ignition campaign, and new opportunities in fusion energy and high energy density science enabled by NIF. The seminar is held in conjunction with Photonics West next January in San Francisco, CA. Visit www.marketplaceseminar.com for more information.
Energy density isn’t the only performance constraint that optical materials scientists must contend with. Relatively limited choices for substrates and coating materials make the ultraviolet, especially at shorter wavelengths, uniquely challenging. But recent developments in optical materials have resulted in new components with attractive properties at “near-UV” wavelengths, thereby providing a boost to applications in this region of the spectrum.
The application of photonics to the life sciences—biophotonics—comes with its own set of constraints. Specific techniques include microscopy and flow cytometry, among others, and all require light sources at many different wavelengths. The relatively recent development of compact, inexpensive solid-state lasers capable of emitting at a variety of visible wavelengths has dramatically expanded bioanalytical capabilities. Among these new devices is a fiber-based laser whose visible output can be continuously tuned across 160 nm (see "Fully tunable visible laser source is valuable for biophotonics").