Developing optical instruments: Computation and verification of hardware specifications and designing optical instruments to industrial applications

A present study addresses some cornerstones in designing high performance optical instruments. In general, the challenge is often due to the combination of different cost constraints and target specifications imposed by end-users and instrumentation companies. Target specifications need to be fulfilled in order to succeed in target application. The cost constraints make it possible for instrument vendors to do global business. The goal is basically to have more customer value and more performance for less money. In order to do this, instruments need to be designed to quality very well. Commercial probes often fail because they tend to provide a fit-for-all solution, which in real life is only suboptimal. Over the years we have learned that optimal "sampling optics" needs to be tailored for each and every application for optimal performance. Otherwise, we cannot get an optimal performance and cost relationship. This work illustrates some of the tools developed and used routinely in VTT Optical Instrumentation Center prior to designing new instruments. The demonstrations aim at showing how application targets can be elaborated backwards from real measurements to hardware design specifications. In practise, we can build high performance into customer-tailored optical instruments with software tools like science-based calibration (SBC), photon and signal-to-noise budgets, and optomechanical design programs. Science-based calibration is the name for the calibration method coined by the end-users in pharmaceutical industry. The method was successfully developed some 10 years ago by Dr. Ralf Marbach. This method development was iniated by several goals: (1) derive hardware specifications, (2) guarantee specificity, (3) estimate SNR, and (4) shorten the time needed for calibration. All these goals are very ambitious (and related). The second and the fourth goals are the most relevant for companies as they potentially deliver two major benefits: (a) no need for extensive calibration set covering designer samples over extended period of time and (b) the extension of the optical method from secondary to primary method in certain applications. The application shown here presents the results of SBC method from near infrared (NIR) made on pharmaceutical powders. The results and methods shown here are directly applicable to existing commercial optical instruments whether ultraviolet (UV), visible, fluorescence, Raman, near infrared, or mid infrared (MIR). In addition, they are directly applicable to designing such instruments like shown in this brief study. This study shows how the above methods can bring along significant benefits in both design and calibration phases of optical instruments. To conclude this presentation, we present also general guidelines how to design a high performance optical instrument.