Search

We have grown neodymium-doped mixed apatite crystals [(Sr/sub 1-x/Ba/sub x/)/sub 5/(PO/sub 4/)/sub 3/F, Sr/sub 5/(P/sub 1-x/V/sub x/O/sub 4/)/sub 3/F, and Ba/sub 5/(P/sub 1-x/V/sub x/O/sub 4/)/sub 3/F] and spectroscopically studied them as potential gain media for a laser source for atmospheric water sensing operating at 944.11 nm. We conclude that an appropriate apatite host material for a 944.11 nm laser should be a mixture of Sr/sub 5/(PO/sub 4/)/sub 3/F. With a small fraction of Ba/sub 5/(PO/sub 4/)/sub 3/F. Precise wavelength tuning around 944.11 nm can be accomplished by varying the host composition, temperature, and threshold population inversion. In apatite crystals of mixed composition, the amplified spontaneous emission (ASE) loss at 1.06 /spl mu/m is predicted to be significantly smaller than that in the end members.

We have grown neodymium doped mixed apatite crystals, (SrxBa1- x)5(PO4)3F, Sr5(P1-xVxO4)3F, and Ba5(P1-xVxO4)3F, and spectroscopically studied them as potential gain media for a laser source for atmospheric water sensing operating at 944.11 nm. We conclude that an appropriate apatite host material for a 944.11 nm laser should be a mixture of Sr5(PO4)3F with a small fraction of Ba5(PO4)3F. The precise wavelength tuning around 944.11 nm can be accomplished by varying the host composition, temperature, and threshold population inversion. In apatite crystals of mixed composition, the amplified spontaneous emission loss at 1.06 micrometers is predicted to be significantly smaller than that in the end members.

Summary form only given. In search for novel photonic materials, we have grown and characterized manganese doped CaYAlO/sub 4/ crystals. This material is relevant to Mn:YaIO/sub 3/, a promising material for holographic data storage. Luminescence of Mn ions can make this material potentially interesting for tunable laser applications. Additionally, spectroscopic studies of Mn ions in this crystal may help in understanding properties of colossal magneto-resistance materials. In this work, using the Czochralski technique, we have grown several manganese doped CaYAlO/sub 4/ crystals and characterized their optical absorption, emission, and EPR properties.

In search for intrinsic optical bistability in solid-state optical materials, we studied cooperative absorption and emission in Yb/sub 3/Al/sub 3/O/sub 12/, Yb/sub 2/O/sub 3/, Yb:Y/sub 2/O/sub 3/, Yb:Lu/sub 2/O/sub 3/ and Yb:Sc/sub 2/O/sub 3/ laser related crystals. The bistability in cooperative luminescence in Yb(6%):Sc/sub 2/O/sub 3/ has been observed.

Summary form only given. Holographic gratings with high diffraction efficiency (>50%) can be recorded in YAlO/sub 3/:Mn with green or blue laser beams. The storage time extrapolated to room temperature is much greater than ten years. Gratings can be erased by heating the crystal to about 270/spl deg/C. These properties in combination with the high optical quality of the crystal give promise to this material for use in holographic data storage.

Using a z-scan technique, we have shown that in Mn:YAlO3 the nonlocal component of the photorefractive response is greater than the local contribution. Although the strongest photorefractive response measured by the z-scan technique was found at light polarization E parallel to the crystallographic axis b (E‖b), the highest holographic diffraction efficiency was obtained at E‖c. The observed seeming discrepancy between the z-scan results and the holographic diffraction-efficiency results is explained by polarization-dependent photoinduced absorption: This absorption has the smallest intensity and the smallest effect on the holographic diffraction efficiency at E‖c.

We propose and experimentally realize the recording of two-color holographic gratings in Mn:YAlO(3), a potential material for holographic data storage. This type of recording allows for nonvolatile retrieval of recorded information at the recording wavelength. We demonstrate two-color recording and readout of a 256 x 256 pixel page using red and green laser beams with a bit error rate of 6 x 10(-7).