A plastic optical element for focusing light to a target includes a first lens and a second lens. The semiconductor integrated circuit device can change an output voltage depending on the threshold voltage. Inlets of the susceptor channels are formed in a sidewall of the hollow. Another method of freeing a pipe stuck in a subterranean well can include determining a location of a portion of the pipe which is biased against a wall of a wellbore by differential pressure, and directing a beam of light to the pipe portion. The filter also acts as a dispersion compensating filter, with the dispersion of the chirped Bragg grating noise filter acting against the dispersion of the optical transmission link.