Linear variable optical filter-based ultraviolet microspectrometer.

Area of Science:

• Optics and Photonics
• Spectroscopy
• Microfabrication

Background:

• Developing compact and high-resolution spectrometers for ultraviolet (UV) applications is crucial.
• Existing UV spectral analysis tools may lack portability or sufficient resolution.
• Integrated circuit (IC)-compatible components offer pathways to miniaturized optical systems.

Purpose of the Study:

• To fabricate an IC-compatible linear variable optical filter (LVOF) for the UV spectral range (310–400 nm).
• To integrate the LVOF with a CMOS camera to create a UV microspectrometer.
• To develop and implement a novel calibration technique for accurate UV spectral measurements.

Main Methods:

• Fabrication of the LVOF using resist reflow and optimized dry-etching techniques.
• Integration of the LVOF onto a commercial CMOS camera.
• Development of a calibration method using a xenon lamp for spectral reconstruction of other sources, like mercury lamps.
• Implementation of a signal processing algorithm for spectral analysis.

Main Results:

• Successful fabrication of an IC-compatible LVOF operating in the 310–400 nm UV range.
• Assembly of a functional UV microspectrometer by mounting the LVOF on a CMOS camera.
• Demonstration of a calibration technique enabling accurate spectral reconstruction.
• Achieved a spectral resolution of 0.5 nm with the developed LVOF-based microspectrometer.

Conclusions:

• The fabricated IC-compatible LVOF is suitable for constructing high-resolution UV microspectrometers.
• The novel calibration technique effectively enhances the accuracy of UV spectral measurements.
• The LVOF-based microspectrometer offers a promising solution for portable and precise UV spectral analysis.