Abstract: A power system, power circuit, and methods for maintaining or providing a constant or substantially constant power source and for reducing and/or minimizing power decay of a predetermined component are provided. Such improvement of power delivery and minimization of power loss is important for precision instrumentation applications. One such application is the infrared (“IR”) source driver for a Fourier Transform Infrared Spectrometer (“FTIR”). The power system and/or circuit may include two integrated circuits in a novel way to make an efficient constant power IR source driver. The method may include having a switching regulator comparing a sample of output voltage with a reference voltage, a second element computing, calculating and/or creating a voltage that is a product of another voltage and a current to obtain a signal proportional to delivered power, and operating a closed loop regulator to provide a constant delivered power to the source.

Abstract: An optical system uses a nonlinear optical medium to alter the frequency of a relatively narrow band light source tunable over a plurality of different frequencies using an optical system for passively directing light to the nonlinear medium at a correct phase matching angle. In this manner, the light from the tunable light source can be efficiently frequency-doubled or frequency-tripled without the need of moving parts. An all prism design provides a system of optimal efficiency.