An ultraviolet lamp shining through this window creates a chemical reaction, causing a thin polymer film to deposit on the quartz. David N. Donovan. An ultraviolet lamp causes the entire quartz surface to become coated, but shining a laser through the quartz can cause the polymer to deposit in specific patterns. Because a laser is a thin beam of focused light, it can be used to draw exact lines. NASA scientists are making these organic thin films on the Space Shuttle to overcome problems caused by convection.
Convection is a circular motion in air or in a liquid created from uneven heating.
On Earth's surface, when a gas or liquid is heated it expands, becoming lighter and less dense. This lighter material rises, mixing with cooler and denser material from above. Such turbulence occurs in the world's weather patterns or even in a pot of water boiling on the stove. Convection creates difficulties when trying to create a uniform film. A UV lamp or laser light will raise the temperature of the film solution, causing the hotter solution to rise.