30p-K-6 Frequency-Locking of Diode Laser Cooling of K Atoms

Carl E. Weiman

Peter D. McDowall, Mikkel F. Andersen

We report on an inexpensive commercial laser diode stabilized to the D(2)-line in rubidium using a simple scheme. The linewidth was reduced to 1.3 MHz without an external cavity, making it suitable for laser cooling and trapping. The system is very robust and the laser frequency can be changed rapidly (within 51 micros) while the laser remains in lock. The frequency of the locked laser drifts less than 850 kHz peak-to-peak over 25 h. We demonstrate laser cooling and trapping using our system.

Takeshi Ikegami, Shinichi Ohshima, Y. Nakadan

Sarah Nagel

The diode laser system for laser cooling on the 1S 0 → 3P1 intercombination line of strontium discussed in this thesis allows us to cool and trap an atomic strontium sample to 15 muK. Samples in this temperature range are useful for the development of the next generation of atomic frequency standards, cold collision studies, and as a step towards quantum degeneracy. This laser system consists of a Littrow configuration external-cavity diode laser, which is frequency locked to a high finesse cavity. The cavity is subsequently locked to an absorption feature to produce a few mW of tunable, stabilized, single mode power at the target wavelength. We present the design and characterization of this system, including a linewidth measurement of 70 kHz, as well as preliminary results from cooling and trapping.

S. Chakrabarti, Ayan Ray, A. Bandyopadhyay +5 more

We report a frequency stabilization technique of a diode laser in a Doppler-free atomic transition used for obtaining the magneto-optical trapping of Rb atoms. This technique, based on side locking to an atomic transition using a servo controller, is very simple and can be implemented straightforwardly to lock the laser at the red detuned frequency position required for laser cooling experiments. The number of trapped atoms and the temperature of the cold cloud have been determined. The effect of trapping the magnetic field on the cloud radius has also been analyzed.

F. G. Major