Trying to get more out of something in exchange for putting less into it is a time-honored tradition in almost all walks of life. Consumer marketing, for instance, takes full advantage of this human desire--enticing us with phrases like "huge discount" or "free offer"--to buy products that we may never actually need or use. In fact, though, many of the products that we do end up buying, either because we want them or need them, are the result of painstaking improvement cycles that involve significant effort directed at more-efficient production and operation. Today`s automobiles, for example, are much more efficiently produced than their predecessors, as well as being much more energy-efficient. The net result overall is a more cost-effective product.
For researchers and designers working in the optoelectronics field, improving device efficiency can mean less heat to be dissipated or less light wasted so that a given component or system can be made smaller and more reliably than before. It may also mean that more optical power can be extracted from the same size package or that less space is required to store a given amount of data. All these benefits contribute to more-cost-effective devices with the potential to open up new applications.
More-efficient lasers
Carbon dioxide lasers have become the de facto standard for many industrial and medical applications. Sealed CO2 lasers provide low output power in a convenient package, while for the high-power requirements, flowing-gas systems provide kilowatt-level output. Now, though, the lines between the two types are blurring--design improvements and increased efficiency have enabled manufacturers to produce output powers up to 600 W from sealed CO2 lasers, thereby providing a real challenge to the flowing-gas systems at these power levels (see p. 105). In the case of solid-state lasers, the advent of diode pumping resulted in an order of magnitude increase in electrical-to-optical conversion efficiency. As a result, water-cooling could be eliminated and the lasers redesigned so that users could fully benefit from the changes--more-reliable devices with more-consistent operation produced a lower overall cost of ownership, again opening up new applications (see p. 127). At the systems-applications level, efficiency improvements resulting from product refinements produce systems that can do more or do it faster, often at lower cost. Laser-based image recorders, for example, are being asked to image faster and at higher resolutions than ever before as the technology moves into new areas (see p. 113).