Recent Development of the Laser Interferometer for Taiji Space Gravitational Wave Detection

Area of Science:

• Astrophysics and Space Science
• Gravitational Wave Detection

Background:

• The Taiji program aims to detect low-frequency gravitational waves.
• Interferometer systems are critical for measuring minute displacements in gravitational wave detectors.

Purpose of the Study:

• To design and specify a full-function interferometer optical bench for the Taiji program.
• To construct and test a first-generation Taiji interferometer optical bench and ground system.
• To analyze and mitigate noise sources affecting the interferometer's performance.

Main Methods:

• Designed a full-function interferometer optical bench (OB).
• Provided detailed parameter specifications for the interferometer system.
• Constructed a ground test system for preliminary testing and calibration.
• Conducted a comprehensive analysis of noise sources (laser frequency, power, thermal drift, angular jitter).

Main Results:

• Achieved noise levels of 1.1 pm/Hz^1/2 at 1 Hz, 5 pm/Hz^1/2 at 0.1 Hz, and 8 pm/Hz^1/2 at 0.01 Hz.
• Demonstrated that the noise levels satisfy the requirements for the Taiji-2 mission.
• Successfully transitioned the interferometer system from a principle prototype to an engineering prototype.

Conclusions:

• The developed interferometer OB meets the stringent noise requirements for the Taiji-2 mission.
• This work represents a significant step towards the engineering prototype phase of the Taiji program's interferometer system.
• The detailed specifications and testing pave the way for future development and deployment.