Modulator-free sub-doppler rubidium cooling using an electrically controllable PZT photonic resonator

Programmable, precision control of laser frequency is essential for quantum experiments and applications such as atomic clocks, quantum computers, and cold-atom sensors. A major challenge in implementing these systems is reducing size, weight, power, and cost (SWaP-C). This includes laser frequency control, which often involves rapid jumps and ramps, such as those used in polarization gradient cooling (PGC) and resonant detection. To avoid the use of power-hungry modulators and frequency shifters like acousto-optic and electro-optic modulators (AOMs, EOMs), we demonstrate an electrically controllable, photonic-integrated PZT-actuated resonator cavity that provides rapid, modulator-free optical frequency control. Locking a 780-nm DBR laser to the cavity, we demonstrate magneto-optical trapping and sub-Doppler cooling of rubidium-87 atoms to 16 µK without external modulators. The device achieves a tuning strength of 1 GHz/V, a modulation bandwidth of 11 MHz, and consumes only 10 nW of electrical power. Additionally, we present a low-cost, accessible, and deployable control system for cold-atom setups based on the Arduino Due platform. The platform is capable of single-microsecond sequencing across 16 channels and arbitrary waveform generation. Finally, we outline a path toward a compact, low-power, chip-scale atomic gravimeter, demonstrating the potential for field-deployable quantum sensors.