Abstract: A cavity ring-down spectroscopy device and method suitable for materials with low and high absorption coefficients. An optical signal introduced into an optical cavity resonates through a length of fiber amplifier coupled to the optical cavity. The optical signal resonates through a fiber amplifier active section resulting in a gain compensating for optical losses. The gain obtained by use of the fiber amplifier is then modulated between two predetermined levels. By virtue of employing an optical fiber, the cavity ring down spectroscopy device and method is insensitive to misalignment and therefore iminently capable of portability.

Abstract: A method is disclosed for generating light in one or more buried layers of a multilayer compound semiconductor material by contacting the material with a tansparent, electrically conducting fluid and passing current between the fluid and the semiconductor material. The measured characteristics of the light emitted from a first semiconductor material may be compared with those measured from a second semiconductor material of known properties, and the properties of the first semiconductor material calculated. Uniformity maps of the compound semiconductor material may be prepared using the patterns of various light emission characteristics measured across the surface of the material.

Abstract: A semiconductor master oscillator generates light which seeds a pair of semiconductor power amplifiers which straddle the oscillator. The power amplifiers have slightly misaligned mirror facets which induce substantial resonator losses in the amplifiers and as a result, the amplifier gain is very high and the modulating speed of the oscillator is also very high.