CoSy

• Compact module for Doppler-free and Doppler-broadened absorption spectroscopy
• Integrated absorption cell filled with Rubidium (Rb), Cesium (Cs), and Potassium (K)
• Designed for laser frequency stabilization
• Can be combined with TOPTICA locking solutions
• Integrated magnetic field compensation for improved measurement accuracy and reproducibility
• Provides long-term optical frequency stability better than 1 × 10⁻⁹
• Supports top-of-fringe stabilization using modulation techniques
• Saves valuable space and setup time in laboratory experiments
• Optional high-frequency modulation version with bandwidth up to 5 MHz

The CoSy system generates both purely Doppler-free and purely Doppler-broadened absorption saturation spectra, which can be fed directly to appropriate stabilization electronics. It can conveniently be used for top-of-fringe stabilization with a modulation technique. The CoSy module helps the customer to save time and space in his experiment. The absorption cell of the Cosy is filled with Rb, Cs and K and one can easily reach a long-term stability of the optical frequency below 1 MHz (corresponding to a relative stability of 10-9) for the considered transitions.

Product Type: Compact Saturation Spectroscopy Module
Spectroscopy: Doppler-free and Doppler-broadened absorption spectroscopy
Atomic Species: Rb, Cs, K
Input Power – Cs: 0.1–3 mW (recommended)
Input Power – Rb: 0.5–3 mW (recommended)
Input Power – K: 0.5–3 mW (recommended)
CoSy Head Dimensions: 80 × 80 × 114 mm³
Control Unit Dimensions: 88 × 125 × 209 mm³
Control Unit Height: 2 height units
Glass Cell Temperature: Adjustable from 20 to 70°C
Cooling: No cooling
Magnetic Field Compensation: Optional AC or DC magnetic field
Input Voltage: 100–120 V / 220–240 V AC
Frequency: 50–60 Hz
Voltage Detection: Automatic
Standard Modulation Bandwidth: 50 kHz–1 MHz*
High-Frequency Modulation Option: Up to 5 MHz

*The modulation bandwidth of the standard CoSy depends on gain and stabilization configuration. TOPTICA also offers a 5 MHz version as an option.

Quantum Physics & Quantum Optics
Laser frequency stabilization for experiments involving atomic and quantum systems, including quantum optics, atom optics, and fundamental quantum technology research.

Quantum Sensing & Metrology
Provides stable atomic frequency references for precision measurement and quantum sensing applications where accurate and reproducible optical frequencies are required.

Laser Frequency Stabilization
Used as an atomic reference for stabilizing laser frequency and improving long-term frequency stability.

Atomic & Molecular Physics
Suitable for experiments requiring precise laser interaction with atomic transitions of Rb, Cs, or K.

Spectroscopy
Generation of Doppler-free absorption signals for high-resolution spectroscopic measurements and laser locking.

Cold Atom & Ultracold Atom Experiments
Can serve as a frequency reference for laser systems used in atom cooling, trapping, and related quantum physics experiments.