89
Growth
of a New Mid-IR Laser Crystal--Ceramare
Corporation, 12-D
Mr.
Robert Uhrin, Principal Investigator,
Dr.
Larry E. McCandlish, Business Official,
DOE
Grant No. DE-FG02-02ER83383
Amount:
$749,418
Rare-earth-doped
potassium lead pentachloride crystals are sought as new mid-IR lasers for
detecting airborne chemical species for national security applications, but a
reproducible growth technique is not yet available. Achieving
high quality crystals also will require suitable raw material preparation
techniques. This project will
develop purification and growth methods capable of producing the high quality
crystals needed for efficient, diode-pumped lasers that function at important
mid-IR wavelengths. First, pure
starting materials, are essential for the growth of these crystals, will be
produced using the material preparation techniques of hydrochlorination and
horizontal zone melting. Then, vertical Bridgman and Czochralski methods will be
used to grow crystals for evaluation. In
Phase I, commercial-lead-chloride and erbium-chloride powders were purified by
zone refining and hydrochlorination. The
powders were used to grow an erbium-doped single crystal of potassium lead
pentachloride by the vertical Bridgman technique.
In Phase II, the vertical Bridgman technique for growing erbium-doped
potassium lead pentachloride will be optimized. The
possibility of applying the Czochralski technique to grow large crystals in a
reactive atmosphere will be investigated. The
laser properties of single crystals grown in the Phase II project will be
demonstrated and optimized.