Advancement in Practical Raman Instrumentation; the Early Years of Jun Zhao’s Career

In the late 90’s, Raman was emerging as a technology that had potential both in process controls and general laboratory analysis. A major driving force was the advancement of compact diode laser sources that were both cost effective as well providing wavelengths that help reduce background fluorescence. During Dr. Zhao’s early industrial career he developed two technologies that helped to overcome both sample and instrumental variabilities. The first was “Automatic Fluorescence Removal Using Shifted Excitation Raman Difference Spectroscopy (SERDS); US Patent 6,281,971B1)” which was used to automate the removal of residual backgrounds such a fluorescence. The second was “Sure_Cal™ technology” which is a method for achieving a standard Raman spectrum that has both short and long-term precision and accuracy and it allows for the collection of the standard spectrum which is independent from typical instrument instabilities. This paper will review the Sure_Cal™ technology and its application to process applications.