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Curvature Wavefront Sensor Curvature Wavefront Sensor Arbitrary Waveform GeneratorArbitrary Waveform Generator
Kenyan KawauchiKenyan Kawauchi
Subaru Telescope (NAOJ)Subaru Telescope (NAOJ)
Mentor: Stephen ColleyMentor: Stephen Colley
Subaru Adaptive OpticsSubaru Adaptive Optics
Earth’s atmospheredistorts light
Telescopeimages blurred
Removes effectsof atmospheric
distortion
Image resolutionimproved
Without AO With AO
AO System ComponentsAO System Components
Wavefront SensorWavefront Sensor
Visible light reflectsoff one sideof membrane
Measure lightintensity
APDs count photonsin each lenslet
Calculate wavefrontphase shift
What vibrates membrane?What vibrates membrane?
Other side of membrane
ProblemProblem
SolutionSolution
• Design your own AWG!
• Use DAC40 board
• Field Programmable Gate Array (FPGA)
• Digital-to-Analog Converters (DACs)
AWG SpecificationAWG Specification Range of period – 100 Hz to 4 kHzRange of period – 100 Hz to 4 kHz Number of points – 1000Number of points – 1000 Voltage resolution – 14 bits (DAC40 DACs) Voltage resolution – 14 bits (DAC40 DACs) Update rate for new waveforms – 0.1 seconds Update rate for new waveforms – 0.1 seconds
(10 Hz)(10 Hz)
Voltage Amplitude
Time
Logic Block DiagramLogic Block Diagram
AWG
Timing Memory
A B
Implement using Quartus IIImplement using Quartus II
Design FlowDesign FlowDesign Entry
(VHDL)Compilation Simulation
ProgramDevice
Simulate DesignSimulate DesignDesign Entry
(VHDL)Compilation Simulation
ProgramDevice
ConclusionConclusion
Dual-stroke waveform conceptDual-stroke waveform conceptEfficient – Only 1 wavefront sensorEfficient – Only 1 wavefront sensorAstronomical objects appear 2.5X brighterAstronomical objects appear 2.5X brighter
In the FutureIn the Future- Interface DAC40 to oscilloscopeInterface DAC40 to oscilloscope- Test AWGTest AWG- Implement in next generation AO systemImplement in next generation AO system
AcknowledgementsAcknowledgements
Stephen ColleyStephen ColleyOlivier Guyon – Subaru AstronomerOlivier Guyon – Subaru AstronomerHideki Takami – AO Project ManagerHideki Takami – AO Project ManagerSubaru Telescope (NAOJ)Subaru Telescope (NAOJ)Center for Adaptive OpticsCenter for Adaptive Optics Funding provided through the Center for Adaptive Funding provided through the Center for Adaptive
Optics, a National Science Foundation Science and Optics, a National Science Foundation Science and Technology Center (STC), AST-987683Technology Center (STC), AST-987683