Special AO/EO Crystal Growth - Ceramic Nd:Yttria Materials
Brimrose Technology has successfully developed a solid-state polycrystalline ceramic laser material using Nd:Yttria (Nd:Y2
) that can be used for remote sensing applications such as LIDAR and DIAL.
Compared to single-crystals, ceramic laser materials offer several advantages with regard to ease of fabrication, shape, size, and control of dopant concentrations. The cubic Y2
single crystal has several favorable properties such as a refractory nature, stability, and optical clarity over a broad spectral range. Furthermore, the thermal conductivity and thermal expansion coefficients are very similar to those of yttrium aluminum garnet (YAG). However, the single crystalline yttria has a high melting temperature of 2430°C and a structural phase transition at 2280°, making it extremely difficult to grow large-sized high quality single crystals.
In collaboration with Rutgers University, Hampton University, and NASA LARC, we have used a scalable production method to make spherical non agglomerated and monodisperse metastable ceramic powders of Nd:Y2
compositions. These compositions were then used to fabricate polycrystalline ceramic material components. Emphasis was directed towards obtaining a fine scale and homogeneous microstructure in the sintered fully dense product. When these metastable powders were consolidated, the grain growth was limited and fine structures were realized. For more info, please contact us
Samples of undoped and doped crystals are shown below:
Transparent Undoped Yttria Sample
Neodymium Doped Yttria Sample
Applications of Nd:Yttria Ceramic Laser Materials:
Nd:Yttria (Nd:Y2O3) that can be used for active remote sensing applications as follows:
- Light Detection and Ranging (LIDAR)
- Differential Absorption Lidar (DIAL)
- Velocity Sensing
In particular, DIAL techniques can be used to determine molecular constituent concentrations present in the atmosphere such as ozone and green house gases, which are of particular interest because of their impact on the environment.
Materials for DIAL Applications
Solid-state lasers play a significant role in providing the technology necessary for active remote sensing of the atmosphere. Nd:Y2O3 is considered to be an attractive material due to its possible lasing wavelengths of around 914 nm and 946 nm for ozone profiling. These wavelengths, when frequency tripled, can generate ultraviolet (UV) light at ~305 and ~315 nm, respectively. For DIAL applications, materials that can be used to generate wavelengths at ~305nm and ~315nm are of interest to NASA. These wavelengths can be generated by frequency tripling the wavelengths 915 nm and 945 nm. Commonly used materials such as Nd:YAG have a transition near 946 nm. Research has shown that Nd:Y2O3 is one of the few materials capable of producing two wavelengths that, when frequency tripled, result in wavelengths around 305 nm and 315 nm.