A versatile microwave source for cold atom experiments controlled by a field programmable gate array.

We present a microwave source that is controlled by a commercially available field-programmable gate array (FPGA). Using an FPGA allows for precise control of the time dependent microwave-dressing applied to a sample of trapped cold atoms. We test our microwave source by exciting Rabi oscillations in a Na spinor Bose-Einstein condensate. We include, as supplements, the complete source code, parts' lists, pin connection diagrams, and schematics to make it easy for any group to build and use this device.

Field-programmable gate array based locking circuit for external cavity diode laser frequency stabilization.

We present a locking circuit for external cavity diode lasers implemented on a field-programmable gate array (FPGA). The main advantages over traditional non-FPGA-based locking circuits are rapid reconfigurability without any soldering and a friendly user interface. We characterize the lock quality by measuring the linewidth of a locked laser using electromagnetically induced transparency in a Rb vapor cell.

Tunable four-pass narrow spectral bandwidth amplifier for use at approximately 508 nm.

We report the implementation of a tunable, narrow-spectral-bandwidth, pulsed, four-pass dye-laser amplifier with strongly reduced amplified spontaneous emission. We present temporal pulse profiles, pulse spectra, and gain measurements of the amplifier output for the case of Coumarin 307 dye as the gain medium, seeded at wavelengths of approximately 508 nm and pumped at 355 nm.

Stark slowing asymmetric rotors: weak-field-seeking states and nonadiabatic transitions.

Stark deceleration is one of the few methods that can be used to slow polyatomic molecules. We present calculations of Stark shift energies, a quantitative analysis of nonadiabatic transition probabilities, and orientational distribution functions applicable to typical Stark slowing conditions for the two small asymmetric rotors nitromethane and acetaldehyde. We show that asymmetric polyatomic molecules are good candidates for Stark slowing.