Design and Fabrication of Grating Demultiplexer Using Hollow Optical Waveguide

Abstract

We present the design and fabrication of a grating demultiplexer with a hollow optical waveguide. The use of a hollow optical waveguide enables temperature-insensitive operations as well as wavelength tunability with the help of microelectro-mechanical system (MEMS) technology. We present the design of a compact reflective concave grating demultiplexer using a hollow optical waveguide whose wavelength resolution is less than 1 nm. In order to reduce the insertion loss, we use a hollow optical waveguide with either metal thin-film coating or dielectric multilayer mirror. We fabricate Au-coated hollow waveguide grating demultiplexers with various device lengths. We measure the spectral response from the fabricated demultiplexers, exhibiting a possibility of high wavelength resolution of below 1 nm. We also present the evaluation of multi-channel operations using a fabricated demultiplexer.

Tunable hollow optical waveguides and their applications for photonic integrated circuits

“…18, by patterning the shape of the circular diffraction grating at the termination of the slab hollow waveguide, a multichannel optical multiplexer/demultiplexer with a diffraction grating type can be produced [2]. Figure 19 shows the initial demultiplexer characteristics of a demultiplexer with a device length of 1 mm on a GaAs substrate [11]. This device allows control of the diffraction grating shape by micromachining.…”

Micromachined vertical cavities and hollow optical waveguides for widely tunable devices

“…We expect temperature insensitive operation as well as wide wavelength tuning at the same time, which has been very difficult for conventional waveguide devices. As an application for tunable optical devices, we are working on a waveguide multiplexer using a hollow waveguide and concave grating [19]. The concave grating has functions of multiplexing and focusing.…”

Investigation and Theoretical Analysis of Low-Loss Three-Dimensional Hollow Waveguides for Widely Tunable Optical Devices

“…Keeping temperature-insensitivity and wide tunability as our target, we have proposed and demonstrated widely tunable hollow optical waveguides with either dielectric multilayers or semiconductor multilayers, as well as a number of widely tunable optical devices based on the hollow waveguide with unique features like temperatureinsensitivity, wide tunability and polarization-insensitivity. 1) These devices include a variable optical attenuator, 2) a tunable multi/demultiplexer based on a concave grating slab hollow waveguide, 3) a tunable spot size converter based on a tapered hollow waveguide, 4) tunable group delay and chromatic dispersion control devices, 5) a tunable hollow waveguide Bragg reflector, 6) a tunable optical switch, 7) and others. The air core of hollow waveguides can be changed using a micro-electro-mechanical system (MEMS) element, which leads to the tunability of propagation characteristics.…”