CM Scientific is a European distributor for GT Advanced Technologies' Advanced Sapphire Materials Group, formerly Crystal Systems Inc., based in Salem, Massachusetts, USA.
The Advanced Sapphire Materials Group (ASMG) has been producing the world's finest and largest sapphire crystals for over 40 years using the Heat Exchanger Method (HEM) process. The group has developed advanced means of producing unique characteristics in sapphire, assessing the subsequent quality and attributes and then correlating these characteristics to the end-user requirements for sophisticated applications. The group is building advanced sapphire solutions for the changing needs of today's technology leaders in lasers, aerospace and semiconductor markets.
GT's Advanced Sapphire Materials Group is the world's leading supplier of HEM Ti:Sapphire and low absorption optical sapphire (LAOS).
Ti:Sapphire crystals are grown using the Heat Exchanger Method, (HEM). This unique method of growth allows for production of the world's largest Ti:Sapphire crystals, with excellent optical and thermal properties. The growth of our crystals takes place in a reducing atmosphere in order to maximize Ti3+ ions, thereby reducing parasitic absorption and maximizing FOM (Figure of Merit) values. The superior homogeneity and low wave front distortion of our laser rods allow laser systems to reach high energy levels without sacrificing beam profile quality. Current production of amplifier crystals of over 200 mm in diameter are ensuring success at the next generation of high intensity laser facilities.
Features and Attributes of HEM® Ti:Sapphire:
Superior Thermal Properties
High Figures of Merit (FOM)
No Bulk Scatter
High Laser Damage Threshold
Large sizes and highly doped material available
Laser Crystals up to 200 mm in diameter
Many design options including rectangles, squares and your unique designs
Absorption values from 0.5 to 10+ /cm @ alpha 514nm
HEM® Sapphire Material
GT's advanced sapphire material is recognized as the highest commercial quality sapphire available with excellent optical, mechanical and transmission properties. Our advanced sapphire production capabilities give our customers the quality and flexibility they need to meet material requirements for the most demanding applications.
GT’s HEM™ sapphire is the most widely used optical sapphire in the world. HEM sapphire exhibits the unique capability of having a broad transmission range from the vacuum ultra violet (VUV), to the infrared (IR) spectrum. HEM sapphire combines high optical transmission, low transmitted wavefront distortion and outstanding mechanical-strength properties at high and low temperatures. Data shows that the homogeneity for all grades of HEM sapphire is in the 0.1 ppm range. This superior crystalline structure combined with low inclusions levels supports excellent performance in a wide range of optical window applications for aerospace and high power lasers and resonators.
GT’s HEM sapphire is used in many mechanical applications because of its large size, strength, abrasion resistance and chemical stability. HEM sapphire has undergone extensive compressive and tensile strength testing at many different temperatures in order to understand its intrinsic failure modes and suitability for different applications.
HEM (LAOS) Low Absorption Optical Sapphire:
Low absorption optimized for your wavelength
Absorption as low as 41ppm/cm @ 1064
Ultra high purity
High power laser window material
HEM Sapphire Optical Attributes:
Low dn/dt over a wide range of lengths, (window temperature gradient does not cause image blur or foresight error)
High resistance to solarization radiation effects
Sapphire optics up to 15” in diameter, no thickness restrictions
Transmitted wave front (TWE), of 1/10 wave peak to valley and better