Advances In The Production Of KNbO3 Crystals

Techniques for producing large single domain potassium niobate (KNb03? crystals suitable for optical devices are discussed. Single crystals measuring up to 25x25x25 mm have been grown from potassium-rich melts using a top seeded technique. An x ray diffractometer and goniometer capable of orienting bulk crystals and fabricated pieces with an accuracy of 15 arc seconds was designed and constructed. An improved method of poling permits the alignment of ferroelectric domains within minutes using infrared heat. Fabrication of crystals has been streamlined through the use of special fixtures. Efficient room temperature second harmonic generation (SHG) of the 532 nm laser line is obtained using the cut.