Jump to first page Optical Channel Optical Channel Monitor Monitor Liang-yu Chen Liang-yu Chen Jian Li Jian Li Arvind Narayanaswamy Arvind Narayanaswamy Dilan Seneviratne Dilan Seneviratne Zhenhai Zhu Zhenhai Zhu Mentored by Mentored by Prof. George Barbastathis Prof. George Barbastathis
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Jump to first page Optical Channel Monitor Liang-yu Chen Jian Li Arvind Narayanaswamy Dilan Seneviratne Zhenhai Zhu Mentored by Prof. George Barbastathis.
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Prof. George BarbastathisProf. George Barbastathis
OutlineOutline
• IntroductionIntroduction
• Grating DesignGrating Design
• ActuatorActuator
• FabricationFabrication
• Sub-componentsSub-components
• Drive signalDrive signal
• Assembly and alignmentAssembly and alignment
• SummarySummary
Goals Goals
DeviceDevice• Monitor optical power in fiber carrying WDM Monitor optical power in fiber carrying WDM
signalssignals
ApplicationsApplications• Real-time optical performance monitoring of Real-time optical performance monitoring of
DWDM networks DWDM networks • Optical add/drop monitoring and diagnosticsOptical add/drop monitoring and diagnostics• EDFA gain balancing EDFA gain balancing
Design RequirementsDesign Requirements
• Scan 10 wavelengths (Scan 10 wavelengths (11 … … 1010) in 10ms) in 10ms
• Central wavelength: 1.5Central wavelength: 1.5mm
• Operate under 50VOperate under 50V
• +/- 10% variation between +/- 10% variation between 11 and and 1010
Device conceptDevice concept
Grating operationGrating operation
actuatoractuator
gratinggrating
OutlineOutline
• IntroductionIntroduction
• Grating DesignGrating Design
• ActuatorActuator
• FabricationFabrication
• Sub-componentsSub-components
• Drive signalDrive signal
• Assembly and alignmentAssembly and alignment
• SummarySummary
Grating designGrating design
• Type of grating - amplitude or Type of grating - amplitude or phasephase
• Pitch and spacing between Pitch and spacing between beams (nominal duty cycle)beams (nominal duty cycle)
xx
sspp
tt
xx
11
00sspp
Amplitude gratingAmplitude grating
Phase gratingPhase grating
Grating DesignGrating Design• Angle of incidence Angle of incidence • Thickness of beams Thickness of beams
00
+1+1
-1-1
00
+1+1
-1-1
--22
Normal incidenceNormal incidence Incidence at an angleIncidence at an angle
Design challengesDesign challenges
• Focusing on the detectorFocusing on the detector spot size
spot overlap
detectordetector
Design challengesDesign challenges
• Focusing on the detectorFocusing on the detector spot overlap
-40 -30 -20 -10 0 10 20 30 40-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
nnn-1n-1 n+1n+1
Overview of the Whole DeviceOverview of the Whole Device• Large number of grating beams neededLarge number of grating beams needed• Natural Frequency is too lowNatural Frequency is too low• Split into piecesSplit into pieces• Efficiency reduction caused by comb drive and space between two piecesEfficiency reduction caused by comb drive and space between two pieces
GratingCombDrive
AnchorFlexure
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....
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OutlineOutline
• IntroductionIntroduction
• Grating DesignGrating Design
• ActuatorActuator
• FabricationFabrication
• Sub-componentsSub-components
• Drive signalDrive signal
• Assembly and alignmentAssembly and alignment
• SummarySummary
Lumped model Resonant frequency >1khZ, for fabrication limitation
and operation limitation
Grating AnchorFlexure
FF ...
F
F
Grating DesignGrating Design
Grating Design (2)Grating Design (2) Resonant frequency
• Grating beam: 4khZ• Whole system: 1.5khZ
Number of gratings for each piece: N=500 Displacement of the gratings: N*22.5nm=11.3um Actuation force Needed: k*22.5nm=53uN
ActuatorActuator
• Requirements: Requirements: Displacement: 11.3um Force 53N Voltage 0-50V
• Options:Options: Electrostatic: Ease of fabrication, Low power, high stroke Piezoelectric: Low strain Thermal: High power, long response time