Planar Rowland spectrometer for fiber-optic wavelength demultiplexing

Area of Science:

• Optics and Photonics
• Fiber Optics Communications
• Spectrometer Design

Background:

• Multimode fiber optics require efficient wavelength demultiplexing.
• Planar optical devices offer miniaturization and integration potential.

Purpose of the Study:

• To fabricate and characterize a planar Rowland spectrometer for multimode fiber-optic wavelength demultiplexing.
• To evaluate the device's performance, including cross-talk isolation.

Main Methods:

• Fabrication of a planar multimode glass waveguide spectrometer.
• Integration of a cylindrical concave grating.
• Characterization using semiconductor lasers (0.825–0.845 µm).

Main Results:

• Achieved 18 dB cross-talk isolation between adjacent fibers (175 µm separation, 100 Å wavelength difference).
• Identified performance limitations including grating efficiency, optical aberrations, and waveguide losses.

Conclusions:

• The planar Rowland spectrometer shows promise as a wavelength demultiplexer for multimode fiber optics.
• Further optimization is needed to overcome performance limitations for practical applications.