SBIR-STTR Award

This Small Business Innovation Research (SBIR) Phase I project will demonstrate the feasibility of growing high-quality fibers of periodically poled Mg-doped LiNbO3 for visible light generation, by a modified version of the laser heated pedestal growth (LHPG) method. Other methods used to grow these crystals have proven to be very expensive and to lead to unreliable results with a very long cycle time, making the use of nonlinear crystals non viable for many applications. Periodically poled crystals poled with the conventional LHPG method exhibit curved ferroelectric domains, which results in a loss of nonlinear optical conversion efficiency, making the technology unpractical for miniature display applications where maximum brightness is required. The company will commercialize LHPG-grown frequency doubling crystals of periodically poled Mg-doped LiNbO3 with higher quality, lower price, faster delivery, and longer lifetimes than the Czochralski-grown crystals available today. In order to accomplish this, the technical approach will be to create and engineer a novel optical after heater which can generate high enough temperatures to enable LHPG to grow high quality thicker fibers, with straight ferroelectric domains thus enabling high nonlinear optical conversion efficiency at 532nm in a very reliable and reproducible way. If successful the proposed LHPG method will produce single-crystal fibers of many compounds with low defect density and low internal strain. Its main limitation had been the inability to grow fibers with diameters larger than 0.8 to 1.2 millimeters and also with straight domains for periodically poled crystals, limiting the optical efficiency of the devices. The team will demonstrate a novel technique for growing LHPG fibers with bigger diameters and ferroelectric domains exhibiting no curvature. This work will enable high-volume manufacturing of frequency doubling chips by LHPG and thereby facilitate the commercialization of miniature projectors (especially the ones to be embedded in cell phones or other handheld devices) and other consumer electronics devices, which will rely on frequency-doubled lasers. The project will contribute to the theory of crystal growth. It will help materials scientists in research institutions to make further discoveries because thicker fibers are easier to study. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)

This Small Business Innovation Research (SBIR) Phase II project will demonstrate how to reduce the cost of manufacturing magnesium-doped lithium niobate (Mg:LiNbO3) crystals by more than an order of magnitude. Frequency-doubling crystals, such as Mg:LiNbO3 can convert 1064-nm light from an infrared laser to 532-nm (green) light. However, LiNbO3 crystals made by the conventional Czochralski technique typically cost $800 each, presenting an economic challenge for consumer applications. The approach is to grow crystals by the laser heated pedestal growth method with a novel afterheater and to pole them in situ. Phase II, enables the development of manufacturing capability for these crystals at a rate of 100,000 crystals per year at a cost of less than $22 each. In Phase III, The manufacturing capacity will be increased to 1,000,000 crystals per year and the manufacturing costs reduced below $8. The proposed cost reduction will enable manufacturers of picoprojectors to increase the brightness of their products by integrating lasers as the light sources instead of LEDs. The technical objectives are to optimize the density of Mg:LiNbO3 ceramic feedstock rods, to increase the manufacturing throughput by optimizing manufacturing yield and automating the growth apparatus. The broader impact/commercial potential of this project is to enhance scientific and technical understanding by demonstrating a) a novel method of growing crystals with lower cost, higher speeds, and greater purity, and b) a way to pole LiNbO3 crystals in situ at lower cost. The project will generate a strong economic impact because many types of handheld consumer electronics devices (cell phones, PDAs, iPods, game terminals, etc.) contain digital data that require visual displays. Picoprojectors can display the content of handheld devices in large formats, but their LED illumination sources can?t generate images with enough brightness to satisfy customers. Laser illumination sources can solve the brightness problem, but lasers are too expensive, primarily because of the cost of the frequency doubling crystals. This project will reduce the cost of these crystals and may thereby enable the picoprojector industry to realize its optimistic growth scenario ($3.6 billion in sales in 2014) rather than its conservative growth scenario ($901 million in sales in 2014). An intern, a science student who is a member of an under-represented group in the nation?s science and engineering enterprise, will be hired to assist with Phase II research