The Wassenaar export controls exist to limit the shipment of products that have potential military applications to non-Wassenaar countries whose military and/or political motivations are unclear. The 40 Wassenaar countries (see table) agree on a common standard for what products can be freely shipped and what products require explicit licenses from the individual governments involved.During the past several years, Wassenaar diplomats have wrestled with the first complete revision of the laser controls since the early 1990s. The new controls were approved last month by the Wassenaar Plenary, and they will be integrated into the legal codes of the Wassenaar nations in 2007.The impetus to revise the controls originated from concerns expressed in 2001 by members of the Laser & Electro-Optics Manufacturers’ Association (LEOMA) about the disconnect between modern laser technology and the existing Wassenaar export controls. Over the next several years, LEOMA worked with industry, the US Commerce Department and the US Department of Defense to draft a proposed revision of the Wassenaar controls that would bring them into sync with the technology of the 21st century.Also during that time, several LEOMA members participated in a revision of the laser section of the Militarily Critical Technologies List, which describes the laser technologies required to fulfill militarily critical missions around the world. Because several of the same individuals contributed to both the military list and the civilian Wassenaar proposal, the proposal benefited from an awareness of military concerns Figure 1. This conference room in Vienna is the site where 40 Wassenaar nations negotiated which lasers can be exported without license to destinations in non-Wassenaar countries. By the spring of 2004, all concerned parties in the US had come to agreement on the details of the proposed revision to the laser controls, and, in April of that year, we presented the proposal to the Wassenaar Experts Group in Vienna (Figure 1). The group comprises delegations from the 40 member states — some delegations larger than others — and meets for two two-week sessions each year. It deals with too wide a range of technologies — from gas masks to batteries to marine engines to lasers — for anyone to be truly an “expert” on all of them. Some delegations bring experts to Vienna to advise on certain technologies, and other delegations must communicate overnight with their capitals for advice. Some delegations come with strict instructions from their capitals, and others have greater flexibility. All official discussions are conducted in English, although other languages abound in the hallways.The laser proposal was one of the more complex issues addressed by the Experts Group, and it was not easily handled. When it was introduced at the April session in 2004, delegates did little more than acknowledge receiving it. It was discussed with some confusion during the September 2004 session, but that year ended disappointingly with the proposal nowhere near acceptance.Nonetheless, it was carried forward into 2005. A French counterproposal put forward that year suggested controlling all lasers according to criteria based on power and wavelength. That increased the complexity of the negotiations but also opened the door for a more radical change in the controls. A weeklong “technical work group” met in Vienna during the summer of 2005 to deal with the laser proposals, but the year ended, nevertheless, with no agreement.By 2006, Wassenaar delegates had become more familiar with the issues surrounding laser controls, and another weeklong work group met that summer and addressed many of them. Finally, in its September 2006 session, the Experts Group approved a grand compromise based on all the proposals that had been put forward during the previous three years. The Wassenaar Plenary made that approval official in December.It is useful to put this recent development into perspective with regard to the long-term effort to control the export of lasers. During the Cold War, the NATO countries plus Japan instituted a control regime called COCOM to limit the export of products with military applications into communist countries. COCOM laser controls were originally a “positive list”; that is, a list of lasers that could be exported without license (Figure 2). In the late 1980s, the US laser industry was chafing under what it considered overly strict controls, and large laser manufacturers were employing several people to do nothing but deal with the paperwork required for exports. Figure 2. When the Wassenaar Arrangement was created in 1994, it adopted the old COCOM laser controls from the early 1990s as the new Wassenaar controls. Those controls have remained in effect with only minor modifications until now. The newly revised Wassenaar controls will become a part of US law in 2007. LEOMA worked with the relevant agencies of the US government and, in 1990, we changed the COCOM controls from a positive list to a negative one — that is, from a short list of lasers that could be freely exported to a list of lasers that could not be exported without a license. This change and the accompanying adjustments in control levels significantly eased the burden on US laser manufacturers.With the end of the Cold War, the COCOM controls became irrelevant, but there still existed a great deal of concern about the destabilizing effects on regional and international security of uncontrolled military exports. To address this, the Wassenaar Arrangement came into existence on Dec. 19, 1995, in the town of Wassenaar, the Netherlands. The old COCOM laser controls were incorporated verbatim into the new Wassenaar controls — and those controls have remained in effect, with only minor modifications, until today.The 2006 revision of the Wassenaar laser controls has had several goals. First, there was a strong desire on the part of many delegations to stop controlling lasers by name and start controlling them by quantifiable parameters. As one delegate succinctly put it, “to control what comes out of the box, not what’s in the box.” This philosophy would end the preferential treatment of one laser relative to another, when both possessed the same military significance. One example of such inequitable treatment was the strict control on ytterbium lasers as compared with the far less strict controls on neodymium lasers, despite the lasers’ operational similarities. Another goal was to address several instances where the current Wassenaar controls were ambiguous or outdated, such as fiber lasers. Fiber lasers did not exist when the COCOM controls were created, and their status under the previous Wassenaar controls was unclear. Another ambiguous issue was nonlinear optics. Did the current controls apply only to light generated by lasers — that is, generated directly by stimulated emission — or did they apply also to light created by converting laser light to other wavelengths with nonlinear devices? The most important case concerned green neodymium lasers, but obviously there were many others. In both these instances, different countries interpreted the controls differently, so clarification was clearly needed.And the controls were sadly outdated with regard to the industrial lasers that have appeared on the scene during the past five or 10 years, those that are capable of multikilowatt outputs but are too massive to have battlefield applications. All these concerns have been addressed in the newest revision of the Wassenaar controls, and they have been addressed in a manner that is acceptable to all 40 member nations.For the vast majority of today’s commercial lasers, the new controls will be no different from the previous ones. The intent of the revision has been to clarify them, to make them easier to understand and implement, and to remove their ambiguities. And, in those cases where there was general agreement that the existing controls were too restrictive, to liberalize them.To meet the desire to “control what comes out of the box, not what’s in the box,” words describing what’s in the box have been deleted from the new controls. Such words include “Q-switched,” “neodymium,” “pulse-excited,” and “fiber laser.” But to avoid disruption to the effectiveness of the controls, numerical parameters have been substituted for these words. Instead of using the word “neodymium,” for example, the new controls impose the same export restrictions on all continuous-wave lasers with output between 975 and 1150 nm. Thus, neodymium and ytterbium lasers and any others in this spectral region are all treated equally.Fiber lasersFiber lasers provided one of the most difficult laser challenges at Wassenaar. Their high power and efficiency, portability and beam quality make them unique, and several delegations advocated a special category for them. Other delegations insisted on maintaining the what-comes-out-of-the-box principle and refused to accept controls based on the words “fiber laser.” In the end, all agreed to control fiber lasers by specifying their overall efficiency: If a single- or multitransverse-mode laser has efficiency greater than 12 or 18 percent, respectively, then unique control levels intended for fiber lasers apply to it. These controls are 100 and 500 W, respectively.The thinking here is that if a laser has the specified efficiency — and it isn’t a diode or a carbon-dioxide laser, which have their own unique categories — then it must be a fiber laser. And even if this logic fails, any laser capable of these efficiencies and power levels would be militarily significant and the licensing requirement, therefore, appropriate. The phrase “fiber laser” appears in only a single place in the new Wassenaar controls: in a note in the opening section that specifies “[These paragraphs] control fiber lasers.” Thus, the ambiguity in the previous controls about whether fiber lasers are controlled has been explicitly removed.Another note specifies: “The control status of lasers incorporating frequency conversion (i.e., wavelength change) by means other than one laser pumping another laser is determined by applying the control parameters for both the output of the source laser and the frequency-converted optical output.” The Wassenaar nations added this sentence to eliminate the ambiguity about nonlinear optics.Finally, the nonsignificance of massive industrial lasers for military applications was recognized with yet another note: “[The paragraph regarding multimode, continuous-wave lasers with output between 975 and 1150 nm] does not control multiple- transverse mode industrial lasers with output power exceeding 2 kW and not exceeding 6 kW with a total mass greater than 1200 kg. For the purpose of this note, total mass includes all components required to operate the laser; e.g., laser, power supply, heat exchanger, but excludes external optics for beam conditioning and/or delivery.”Meet the authorBreck Hitz has been the executive director of LEOMA since 1988. Since 2003, he also has served as senior technology editor of Photonics Spectra; e-mail: firstname.lastname@example.org.