Compact and robust design of the optical system for cold atom interferometer in space

Area of Science:

• Atomic physics and interferometry
• Space-based instrumentation
• Optical engineering

Background:

• Atom interferometers (AI) are crucial for precise measurements but are complex, especially for space applications.
• Existing AI optical systems face challenges in terms of size, weight, and environmental stability.

Purpose of the Study:

• To design and develop an integrated and robust optical system for the China Space Station atom interferometer (CSSAI).
• To optimize the design for reduced complexity while enabling dual-species AI capabilities in a space environment.

Main Methods:

• Utilized a fused silica optical bench with bonding technology for compactness and thermal stability.
• Incorporated spatial structures for vibration isolation and heat transfer management.
• Assembled and tested the optical system, including thermal and mechanical evaluations before space launch.

Main Results:

• The optical system measures 250x240x104 mm and weighs 5.2 kg.
• Successfully passed pre-launch thermal and mechanical tests.
• Demonstrated stable laser power (<15% change from ground to space) and low long-term fluctuations (<2.5% over months in space).
• Achieved cold atom preparation and interference in the space environment.

Conclusions:

• The developed optical system is highly integrated and robust for space-based atom interferometry.
• It provides a foundational design for future cold atom payloads on space missions.
• The system's performance in space validates its suitability for demanding scientific applications.