Second- and higher-order waveguide grating filters. 2: experiment

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Waveguide Technology

Background:

• Waveguide grating filters are crucial optical components.
• Accurate characterization of their spectral response is essential for device design.
• Previous theoretical models require validation through experimental data.

Purpose of the Study:

• To experimentally determine reflection, transmission, and radiation loss coefficients for waveguide grating filters.
• To investigate the wavelength dependence of these optical coefficients.
• To validate a Green's function calculation method for grating filter spectral response.

Main Methods:

• Systematic measurements of reflection, transmission, and radiation loss.
• Characterization of second- and third-order waveguide grating filters.
• Comparison of experimental data with theoretical calculations.

Main Results:

• Precise coefficients for reflection, transmission, and radiation loss were obtained.
• The dependence of these coefficients on incident light wavelength was detailed.
• Experimental measurements showed excellent agreement with Green's function calculations.

Conclusions:

• The Green's function approach provides a simple and accurate method for predicting grating filter spectral responses.
• Experimental validation supports the utility of this theoretical framework.
• This work advances the understanding and design of waveguide grating filters.