the two materials are well matched with regard to thermal expansion as well as chemical

Misture and Sundaram believe that cordierite glass-ceramics are most suitable as a diamond coating substrate because the two materials are well matched with regard to thermal expansion as well as chemical and thermal stability under the processing conditions of interest to Group4Labs. The "sacrificial" substrate must also be inexpensive because it is disposed of during processing.

According to Misture, in the past, diamonds had been deposited on substrates with different thermal expansion coefficients, which resulted in "mismatch failure and thermal cracking." The main challenge is matching the thermal expansion coefficients of the substrate and the coating. Misture and Sundaram hope to accomplish that by manipulating the glass chemistry and controlling a specific crystal phase from crystallising out.

The instrument manufacturer from Munich will be launching its new goniometers at the leading exhibition for lighting systems in a world premiere on 15-20 April. The LGS 250 and LGS 1000 series of goniophotometers can be used for analysis of angle-dependent spatial radiation properties from SSL luminaires and lamps, and LED modules. Additionally the ISP 1000 integrating sphere is also being presented. It has been fitted with sample holders specifically designed for SSL applications and permits accurate determination of luminous flux and colorimetric quantities of SSL light sources.

The new products give Instrument Systems a complete model series of goniophotometers and integrating spheres with a range of different sizes. The manufacturer of high-precision spectroradiometers is bundling its long track record of experience in LED test and measurement and will now be able to supply complete measurement systems for the SSL market.