Continuously variable Fourier filters fabricated using varying angle glancing angle deposition for chip-scale...

Area of Science:

• Optics and Photonics
• Spectroscopy
• Materials Science

Background:

• Low-cost spectroscopy is crucial for applications like food inspection and disease detection.
• Existing spectroscopic systems are often mechanically fragile due to multiple optical components.
• Previous work utilized thin dielectric films for Fourier filtering, but required multiple fabrication steps.

Purpose of the Study:

• To develop a simplified and more robust method for creating Fourier filters for spectroscopy.
• To overcome the limitations of multi-step lithographic processes for filter fabrication.
• To demonstrate a novel single-step deposition technique for continuously variable Fourier filters.

Main Methods:

• Employed a single-step electron-beam evaporation technique.
• Utilized glancing angle deposition with a continuously varying angle.
• Produced multiple variable Fourier filters in a single deposition run.
• Integrated the variable filter onto a 38-channel linear detector.

Main Results:

• Successfully fabricated continuously variable Fourier filters using a novel single-step method.
• Demonstrated the capability to produce numerous filters with varying characteristics simultaneously.
• Validated the performance of the integrated filter and detector system.

Conclusions:

• The developed technique offers a significant advancement in fabricating Fourier filters for low-cost spectroscopy.
• This method enhances mechanical robustness and simplifies the manufacturing process of spectroscopic devices.
• The approach holds potential for broader applications in fields requiring accessible spectroscopic analysis.