One other approach has already been developed: a sun-pumped laser. Sunlight focused onto the side of the laser (see [Figure 32]) provides the pumping power, enabling the device to put out 1 watt of continuous infrared radiation, enough for special space applications. Descendents of this device could produce visible light if this is deemed desirable.
Another approach, using chemical lasers, is even more intriguing and may have greater consequences. Chemical lasers will derive their energy from their internal chemistry rather than from the outside. A mixture of two chemicals may be all that is needed to initiate laser action aboard a spacecraft or satellite. (Chemical lasers also offer the promise of even greater concentrations of power than have been achieved heretofore, which may make them useful in plasma research.)
With all these possibilities, it may still be that spacecraft will need more power than is available on board. The narrow beam of the laser offers one more fascinating possibility, especially in the case of satellites relatively near earth. The light of a laser might actually be used to beam energy to a receiver, either for immediate use or storage. It would then become possible to “refuel” satellites at will, giving them much greater capabilities.
If available laser power is great enough, laser beams might even be used to push satellites back into their proper orbits when they begin to wander off course, as they almost invariably do after a while.
Figure 32 Artist’s rendering of sun-pumped laser as it would operate in space. The sun’s rays are collected by a parabolic reflector and are focused on the laser’s surface by two cylindrical mirrors.
Sun Parabolic Collector Hyperbolic-cylindric secondary mirror Semi-circular-cylindric tertiary mirror Laser beam
A LASER IN YOUR FUTURE?
Atomic energy, only a scientific dream a few short years ago, is now providing needed power in many parts of the world. In the same way, the laser, also an atomic phenomenon, has made its way out of the laboratory and into the fields of medicine, commerce, and industry. If it hasn’t touched your life as yet, you need only be patient. It will.
Indeed the most exciting probability of all is that lasers undoubtedly will change our lives in ways we cannot even conceive of now.