Prototype of an ultra-stable optical cavity for space applications

Area of Science:

• Physics
• Optical Engineering
• Space Technology

Background:

• Ultra-stable cavities are essential for high-precision frequency standards.
• Space missions require robust systems resistant to environmental perturbations.

Purpose of the Study:

• To design and characterize an ultra-stable cavity prototype for space applications.
• To optimize thermal and vibration sensitivities for space environments.
• To evaluate the system's performance under operational constraints.

Main Methods:

• Finite element modeling for optimization of thermal and vibration sensitivities.
• Mechanical design featuring rigid mounting for perturbation decoupling.
• Thermal isolation using gold-coated aluminum shields within a stainless steel enclosure.
• Experimental evaluation of vibration sensitivity and fractional frequency instability.

Main Results:

• Achieved axial vibration sensitivity of (4 ± 0.5) × 10⁻¹¹/(m·s⁻²).
• Transverse vibration sensitivity below 1 × 10⁻¹¹/(m·s⁻²).
• Fractional frequency instability of ~1×10⁻¹⁵ at short integration times, reaching 5-6×10⁻¹⁶ at 1 second.
• Designed for transportability, high acceleration tolerance (up to several g), and a wide temperature range [-33°C; 73°C].

Conclusions:

• The prototype demonstrates high stability and robustness suitable for demanding space missions.
• The engineered mechanical interface effectively decouples the cavity from environmental disturbances.
• The achieved performance metrics meet the stringent requirements for future space-based frequency standards.