Achromatic half-wave plate for submillimeter instruments in cosmic microwave background astronomy: modeling and...

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Birefringent devices are crucial for polarization control in optical systems.
• Accurate modeling of their frequency-dependent optical properties is essential for device design.

Purpose of the Study:

• To develop and validate a high-precision simulation model for multiple-plate birefringent devices.
• To assess the performance of a specific achromatic five-plate device.

Main Methods:

• Adopted and modified an existing formalism for optical simulations.
• Simulated transmission, reflection, and absorption as a function of frequency.
• Validated the model by comparing simulation results with measured properties of a five-plate device.

Main Results:

• The model accurately predicts optical properties of birefringent devices.
• An achromatic five-plate device demonstrated excellent performance with minimal phase shift variation (< 2 degrees) over a broad bandwidth (Deltav/v ≈ 1).
• The device operates effectively at millimeter wavelengths.

Conclusions:

• The developed formalism is a powerful design tool for birefringent polarization modulators.
• The model enables high-accuracy specification of optical properties for these devices.