Performance Lasers for LHPG Fabrication
Challenge
Laser Heated Pedestal Growth (LHPG) is a highly delicate fabrication technique for growing the highest quality crystals. This is accomplished by melting a narrow region with a highly controlled CO2 laser beam. The focused beam is moved along the crystal, or floating zone. As the molten region melts the impure solid at its forward edge, a wake of purer, solidified material is left behind. However, for such a process to produce the highest quality of sapphire optical fibers, active monitoring and control of all parameters of this process is crucial.
Solution
A unique light source is required to provide the high pulling rates of materials with very high melting points. This source must have unparalleled power stability to produce a uniform molten zone whose viscosity doesn’t negatively impact the drawing process. The AL30-ST-FCCL from Access Laser provides the required functionality in a compact size, allowing easy integration into the complex vacuum system that holds the target crystal. Superior mode quality is also critical so the laser can to be properly guided by a reflaxicon, which radially distributes the laser energy over the molten zone, thus reducing thermal gradients even further.
Result
The system’s ability to grow tapered fibers enables the fabrication of compact, evanescent wave absorption sensors with exceptionally high sensitivity. Likewise, due to the sophistication and versatility of the system, made possible by Access Laser technology, the monolithic, all-crystalline ultra-probe for the MicroMaterials OptoTemp 2000 fiber-optical thermometer, has the highest temperature measuring capability of any comparable device on the market.
To request more information or a quotation for Access Laser products, contact IL Photonics.