A highly linear superconducting bolometer for quantitative THz Fourier transform spectroscopy

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• Transition Edge Sensors (TES) are highly sensitive detectors used in various scientific applications.
• Silicon composite bolometers are commonly used but have limitations in dynamic range and linearity.
• Terahertz (THz) spectroscopy requires detectors with broad spectral coverage and excellent performance.

Purpose of the Study:

• To design and develop a superconducting Transition Edge Sensor (TES) bolometer for terahertz (THz) spectral range (0.1–3 THz).
• To achieve a higher dynamic range and linear response compared to existing silicon composite bolometers.
• To enable advanced Fourier transform spectroscopy applications.

Main Methods:

• Design of a TES bolometer utilizing a thin film metal mesh absorber.
• Integration of a superconducting thermistor and Si3N4 membrane technology.
• Fabrication and characterization of a prototype bolometer.

Main Results:

• The designed TES bolometer operates effectively in the 0.1–3 THz spectral range.
• The prototype demonstrated a higher dynamic range and a highly linear response.
• Performance metrics were comparable or superior to commercially available silicon composite bolometers.

Conclusions:

• The developed superconducting TES bolometer is a promising alternative for THz Fourier transform spectroscopy.
• The design offers significant advantages in linearity and dynamic range.
• Successful prototype implementation validates its potential for advanced scientific applications.