Variable-finesse wideband Fabry-Perot wavemeter for far-infrared and millimeter waves

Area of Science:

• Physics
• Optical Engineering
• Spectroscopy

Background:

• Far-infrared and millimeter wave spectroscopy require precise wavelength measurement tools.
• Fabry-Perot interferometers are established for spectral analysis but often limited in bandwidth or tunability.
• Polarizing optics offer unique control over light properties, potentially enhancing wavemeter performance.

Purpose of the Study:

• To develop a high-bandwidth scanning Fabry-Perot wavemeter for far-infrared and millimeter wave applications.
• To investigate the use of polarizing reflectors for tunable spectral analysis.
• To achieve a broad wavelength measurement range using controlled interference fringes.

Main Methods:

• Fabrication of a scanning Fabry-Perot wavemeter incorporating two striped polarizing reflectors.
• Adjustment of the relative angle between the strip directions of the polarizing reflectors.
• Exploitation of variations in reflectivity finesse based on the angle adjustment to generate interference fringes.
• Experimental validation of the wavemeter's performance across a wide spectral range.

Main Results:

• Successful development of a high-bandwidth scanning Fabry-Perot wavemeter.
• Demonstration that varying the relative angle of polarizing reflectors tunes the reflectivity finesse.
• Generation of Fabry-Perot interference fringes across a broad spectrum.
• Experimental verification of a wavelength measurement range from approximately 100 to 3000 micrometers.

Conclusions:

• The developed polarizing reflector-based Fabry-Perot wavemeter is effective for broadband far-infrared and millimeter wave measurements.
• The angular control of polarizing reflectors provides a versatile method for tuning wavemeter characteristics.
• This technology significantly expands the accessible wavelength range for spectral analysis in the far-infrared and millimeter wave spectrum.