We show that a highly reliable and compact wavemeter incorporating a reference laser and traveling Michelson interferometer can be controlled, and the unknown wavelength determined, using readily programmable microcontroller circuits. These chips, powered by a supply, each replace a network of many electronic components and enable equipment to be built and debugged in a very short time, to occupy a very small footprint and to be easily modified. With this wavemeter we demonstrate the ease with which programmable microcontrollers can play an important role in a physics research laboratory. We also present, for the first time, the stabilization of an internal mirror HeNe reference laser through direct compression of the glass tube, resulting in stable, mode power balanced operation for a period of more than . This novel stabilization scheme enables a much higher bandwidth and shorter settling time of the servo system than previous heater-based approaches by overcoming technical problems associated with the thermal conductivity of the heater/laser system. The accuracy of the wavemeter has been confirmed by measuring the wavelength of a tunable diode laser as it was scanned across the D1 and D2 lines of , detected through optogalvanic spectroscopy.
REFERENCES
We have provided details of the particular components we used to assist readers who wish to duplicate our procedures. Components from other manufacturers may of course offer similar or better performance.
