F. M. Schellenberg

Generation of blue cw coherent radiation by sum frequency mixing in KTiOPO4

The wavelength, angle, and temperature tolerances of a new room‐temperature noncritically phase‐matched frequency mixing process involving type II frequency mixing of 1064 and 809 nm radiation in potassium titanyl phosphate (KTiOPO4) are measured. The angular and temperature bandwidths are found to be unusually wide. Device applications for upconversion of diode pumped neodymium:yttrium aluminum garnet laser sources to the blue spectral region are explored.

Generation of blue light by intracavity frequency mixing of the laser and pump radiation of a miniature neodymium:yttrium aluminum garnet laser

Potassium titanyl phosphate (KTiOPO4,KTP) has been used to generate blue 459‐nm radiation by intracavity sum frequency mixing of the circulating 1064‐nm laser radiation of a miniature neodymium:yttrium aluminum garnet laser and the 809‐nm radiation used as the pump source. A blue output power of approximately 1 mW cw was obtained using 275 mW of pump power from an infrared dye laser. Gain‐switched operation leading to high 459‐nm peak powers was demonstrated. Direct rapid modulation of the blue radiation was achieved by modulating the pump. In preliminary experiments a high‐power laser diode was used as the pump source for the generation of blue radiation.

Technological aspects of frequency domain data storage using persistent spectral hole burning.

Persistent spectral hole burning permits use of optical frequency for encoding digital information at cryogenic temperatures, with storage densities far beyond the limits of conventional laser–disk recording. In the work presented here, several key technological issues of such a storage system have been investigated. Data were encoded with high spatial and spectral resolution using a specially designed cryostat. The fast tuning characteristics of semiconductor diode lasers were studied to test the feasibility of fast data access in the frequency domain. Fast readout was investigated in a simulation experiment using heterodyne detection with frequency modulated diode lasers.