Multiband wavelength demultiplexer based on digital planar holography for on-chip spectroscopy applications

Area of Science:

• Photonics and optical engineering
• Integrated optics
• Spectroscopy

Background:

• On-chip spectroscopy requires efficient wavelength separation.
• Existing demultiplexers face limitations in channel density and spectral resolution.
• Digital planar holograms offer a novel approach for integrated optical devices.

Purpose of the Study:

• To propose and demonstrate a novel multiband wavelength demultiplexer for on-chip spectroscopy.
• To leverage computer-designed digital planar holograms for precise light manipulation.
• To report on the fabrication and characterization of the proposed device.

Main Methods:

• Computer-aided design of digital planar holograms with millions of precisely located lines.
• Fabrication of the holographic demultiplexer chip.
• Characterization of the device's performance across four visible light bandwidths.

Main Results:

• Successful fabrication and characterization of the digital holographic demultiplexer.
• Operation in four distinct visible bandwidths (477.2-478.0 nm, 528.8-529.9 nm, 586.4-587.7 nm, 628.9-630.4 nm).
• Achieved 96 spectral channels with a minimum channel spacing of 0.0375 nm/channel.

Conclusions:

• The proposed digital holographic demultiplexer is a viable technology for on-chip spectroscopy.
• The device demonstrates high channel density and spectral resolution.
• This technology opens new possibilities for miniaturized spectroscopic systems.