High-performance 1-10  THz integrating sphere

Area of Science:

• Astronomy and Astrophysics
• Optical Engineering
• Terahertz Science

Background:

• The SPICA far-infrared instrument (SAFARI) requires a calibration source for its transition edge sensor readout circuits.
• High-performance integrating spheres operating at 34-230 µm are essential for SAFARI's calibration needs.

Purpose of the Study:

• To develop a novel process for preparing terahertz integrating spheres.
• To create a high-performance calibration source for the SPICA far-infrared instrument (SAFARI).

Main Methods:

• A novel preparation process involving sandblasting, wet-etching, and gold plating of aluminum surfaces was developed.
• Characterization of surface morphology and reflectance in the 1-10 THz range.
• Numerical simulations of output power distribution were performed.

Main Results:

• The developed process resulted in aluminum surfaces with rough morphology but high reflectance (0.91) at terahertz frequencies.
• Measured output power distribution closely matched numerical simulation results.
• The integrating sphere is suitable for SAFARI's operational wavelengths (34-230 µm).

Conclusions:

• A novel method for creating terahertz integrating spheres with high reflectance has been successfully demonstrated.
• The developed integrating sphere meets the performance requirements for calibrating the SPICA far-infrared instrument (SAFARI).
• The findings support the advancement of infrared astronomy instrumentation.