2-D digital micromirror array forms multiple-wavelength add-drop filter

Researchers at the University of Central Florida Center for Research and Education in Optics and Lasers (CREOL) and department of electrical and computer engineering have shown that a two-dimensional (2-D) digital micromirror (DMD) can act as a fault-tolerant add-drop filter for dense-wavelength-division-multiplexing applications. The DMD was coupled by free-space optics to fiber-connected array-waveguide-grating (AWG) multiplexers that form a 2-D in-out feed. Most add-drop filters for telecommu

2-D digital micromirror array forms multiple-wavelength add-drop filter

Researchers at the University of Central Florida Center for Research and Education in Optics and Lasers (CREOL) and department of electrical and computer engineering have shown that a two-dimensional (2-D) digital micromirror (DMD) can act as a fault-tolerant add-drop filter for dense-wavelength-division-multiplexing applications. The DMD was coupled by free-space optics to fiber-connected array-waveguide-grating (AWG) multiplexers that form a 2-D in-out feed. Most add-drop filters for telecommunications rely on on-chip planar technology with interconnections such as fibers or on-chip arrays of integrated-optic waveguides and switches.

The CREOL design took light at 488, 532, and 632.5 nm through the AWG multiplexers to the very-high space-bandwidth-product DMD (more than 0.5 ¥ 106 mirrors), where macropixels of several hundred micromirrors each switched individual wavelengths. The design is fault-tolerant, partly because individual mirror failures have less effect on optical-alignment sensitivity and because of the overall robustness of the device. Graded-index (GRIN) fiber to GRIN-fiber coupling was shown to be effective when the DMD was the active routing element. The next step is to test the filter at the 1550-nm telecommunications wavelength.

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