Optics & Infrared Sensing
The IR sensing group has several unique electronics capabilities including precision power supply design, primarily for low noise laser operation, and low noise analog amplifier design, encompassing a range from signal pre-amplifiers for use with sensitive photo-detectors through to quite high voltage amplifiers for precision Piezo electric control.
An example of this capability is the quantum cascade laser current controller series (QCLx) that is now used as a standard at the laboratory for operation of these devices. These current controllers operate close to the theoretical level determined by the Johnson and shot noise limits of their internal components, can be scanned rapidly, and are stable over long time periods. These characteristics are important for frequency-stable, narrow line width laser operation, and have a direct impact on laser-based sensor performance.
Servo Design and Laser Stabilization
A more specialized example of the unique electronics capability of the IR sensing group is that of advanced servo system design. One application of this is precision temperature controllers, allowing sub-milliKelvin control of lasers, cells, etc., which in turn supports precision operation of lasers and sensor systems. A high speed application of the same capability allows the frequency stabilization of laser systems by locking them to optical cavities or molecular transitions. Uses include ultra fine resolution molecular spectroscopy through to ultra narrow line width systems for very long distance laser radar or active heterodyne applications.