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.
Quasi-phase matched lithium niobate (LiNbO3, LN) devices have generated a lot of interest for all-optical fiber communications and other systems. The goal of this Small Business Innovation Research project was to 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. In this project we have demonstrated 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 consumers applications. Our novel approach was to grow crystals by the laser heated pedestal growth method with a novel afterheater and to pole them in situ. During Phase II and Phase IIB, we have gained the ability to manufacture these crystals at a rate of 100,000 crystals per year at a competitive cost. During this project we have: Designed and assembled a novel afterheater for our laser heated pedestal growth system. Grown periodically poled magnesium-doped LiNbO3 fibers by the following process: created ceramic magnesium-doped LiNbO3 rods, used those ceramic rods as feedstock to grow LiNbO3 fibers by the laser heated pedestal growth method, and poled the fibers in situ. Tested the strain and the uniformity of ferroelectric domains in the grown fibers. Begun to operate a new LHPG system dedicated to production. Established and documented standard procedures for growing crystals. Created an automated control system with a graphic user interface. Optimized growth yield. Demonstrated that we can manufacture crystals with conversion efficiency of 28%. Optimized device performance yield. Demonstrated that we can manufacture Mg:LiNbO3 frequency doubling crystals at a rate of 11,000 crystals per month . Demonstrated that we can operate the manufacturing system with uptime of 67%. Sampled our crystals to several customers. Grown several batches of thicker ppMg:LiNbO3 with different electrode configurations (95% completed) Improved fabrication techniques (95% completed) Improved production yields (60% completed) Implemented proof of concept for module (75% completed) These results indicate that in our Phase II research, we have proven technical feasibility, justified the intended commercial applications, demonstrated our ability to conduct research and development, and justified NSF support. Broader Impacts This SBIR project enhanced 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, for example, 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 allow reduce the cost of these crystals and may thereby enable the projection 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). Shasta Crystals hired several interns during the course of this project to assist with various scientific and manufacturing processes.
