Towards the end of 2020, with our previous UV-vis-NIR (ultraviolet, visible and near-infrared) spectrophotometer nearing the end of its useful life, TSL took the decision to invest in a high-end replacement from Agilent. In December 2020, our new Agilent Cary 5000 UV-vis-NIR twin-beam spectrophotometer was delivered and installed in the cleanroom of our Vacuum Optics division.
The Cary 5000 has a wider spectral range than the instrument it replaces, covering the wavelength spectrum from 175 nm to 3300 nm. Its main use will be in measuring the optical performance of our vacuum viewports with anti-reflective coatings. The sample chamber is large enough to accommodate our more frequently manufactured viewports, but it is also adaptable for the substantially larger viewports that we manufacture less often. We also invested in a near-normal reflectance accessory, so measurements can be made of both reflectance and transmittance.
The Cary 5000 will also be invaluable in assuring the quality of bought-in optical materials, including optical-grade CVD (chemical vapour deposited) diamond. We are currently studying the scientific literature on the relationship between optical absorption and thermal conductivity of CVD diamond with the intention of using the optical transmittance of thermal grade CVD diamond as a quality assurance measure.
The Cary 5000 joins its sister instrument in the cleanroom, a Cary 630 FTIR (Fourier-transform infrared) spectrometer. TSL has extended the capabilities of the 630 with the purchase of a transmittance accessory, so that in principle we now have the capability to measure reflectance or transmittance across wavelengths from UV to nearly 30 µm, well into the mid-infrared, though taking measurements near to the limits of an instrument’s range can be challenging. It is hoped that future investments will extend our in-house coating capabilities further towards this region of the infrared.