lecture 18 photonic signals and systems an introduction by
TRANSCRIPT
Lecture 18
Photonic Signals and Systems- An Introduction
- By- Nabeel A. Riza *
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• Text Book Reference: N. A. Riza, Photonic Signals and Systems – An Introduction, McGraw Hill, New York, 2013.
Optical MEMS-based Photonic Designs - Overview
The TI Digital Micromirror Device (DMD)
The optical MEMS DMD-based laser beam profiler
DMD-based camera
MEMS-based broadband fiber-optic (FO) SMF variable optical attenuator (VOA).
DMD-based fiber-optic SMF variable optical attenuator
DMD-based fiber-optic SMF multi-wavelength equalizer.
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The TI Digital Micromirror Device (DMD)The Figure 5.21 device as shown resembles the layout of the famed Texas Instruments (TI) Digital Micromirror Device (DMD) where over one million tiny mirrors are electrically actuated to produce one of two 1D tilt states, for example, +12° and -12°. Hence, a highly reliable digital state optical device is formed.
The DMD has been extensively used for color projectors.
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2-D Micromirror Array Chip with 1 million micro-mirrors
From Texas Instruments (TI)
Each micromirror is about 14 micron square and tilts by +12 degrees or – 12 degrees
Optical Micro-Electro-Mechanical (MEMS) Devices
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2D DMD Operation – The Micromirror has 2 tilt states
The DMD is a two-tilt state-micromirror-array device. Each micromirror in the DMD is programmed such that a +θ (black-color micromirror) and - θ -state (white-colormicromirror) vertical boundary exists.
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2D Digital Micromirror Device (DMD) based Laser Beam PROFILER
2D DMD chip operating as a software-programmable moving pin-hole to sample the laser light beam pattern. The +θ state micromirror forms the moving PINHOLE. The - θ beams of light are the non-pinhole sites with light directed to the block.
The point photo-detector measures the +θ optical power for the pinhole locations, one at a time, at different locations on the DMD.
All pin-hole optical power data is used to construct the optical irradiance (intensity) map on the incident laser beam.
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DMD-based Optical Camera
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SMF broadband high-dynamic-range VOA design usingmicromechanics
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Fault-tolerant 100 % reliable SMF fiber-optic variable optical attenuator using DMD
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Fault-tolerant SMF fiber-optic multi-wavelength equalizer using DMD (a digital MEMS device)
GRIN Lens
Control the state of the Many Micromirrors in each beam spot to control how much lightTravels back into fiber GRIN lens and fiber and back to the circulator. E.g., 16 attenuationlevels controlled by Controlling 16 micromirrors in the DMD for that specific wavelength.
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