Further Study of Glass Fiber Lasers for Optical Data Processing

摘要

Investigations were undertaken to find laser effects which can be useful in optical logic functions, and to devise techniques for further development of the effects. The emphasis was on neodymium doped glass and fiber lasers. A technique was developed for generating two pulses of laser energy of submicro-second duration and variable time separation from 0.3 to 1 microsecond. The technique can be refined to yield order-of-magnitude improvement in both minimum and maximum time separation. Beveling the ends of fiber lasers was investigated as a technique for controlling oscillation modes. As the bevel angle was increased, oscillation modes were shifted from near axial to higher order, the latter giving a hollow cone output pattern. Interactions of light from a GaAs diode laser with a pumped neodymium fiber laser were investigated. It was found that the pumped laser material acts as an excited state absorber for the 0.84 micron radiation from the diode laser. Positive steps were taken toward an optical Y junction consisting of high index glass channels imbedded in low index glass. Equations governing the behavior of a saturable absorber in fiber form have been derived. A fiber laser, consisting of a passive glass core and a neodymium doped cladding, was made to lase. (Author)