A miniature frequency-stabilized VCSEL system emitting at 795 nm based on LTCC modules

We present a compact frequency-stabilized laser system locked to the Rubidium absorption line of a micro-fabricated reference cell. A printed circuit board (PCB) is used to carry all the components and part of the electronics, and low-temperature co-fired ceramic (LTCC) modules are used to temperature-stabilize the laser diode and the miniature Rubidium cell (cell inner dimensions: 5 mm diameter and 2 mm height). The measured frequency stability of the laser, in terms of Allan deviation, is ≤8×10⁻¹⁰ for integration times of 10³–10⁵s. The current overall dimensions of the system are 70×40×50 mm³, with good potential for realization of a frequency-stabilized laser module with few cm³ volume.