Optimizing the Throughput of Optimizing the Throughput of an Optical Systeman Optical System

Lisa PhillipsLisa Phillips

Textron SystemsTextron Systems

Mentor: Robert NolanMentor: Robert Nolan

Advisor: Robert LercariAdvisor: Robert LercariR&D Team: Tim Georges, Curtis KruppR&D Team: Tim Georges, Curtis Krupp

Chris Matsuura, Donna Rohrer, Clint SmithChris Matsuura, Donna Rohrer, Clint Smith

Home Institution: Maui Community CollegeHome Institution: Maui Community College

OutlineOutline

The Air Force and Textron SystemsThe Air Force and Textron SystemsThe Laser Beam Director (LBD) The Laser Beam Director (LBD)

Transmitting TelescopeTransmitting TelescopeThe Beam Relay Optics SystemThe Beam Relay Optics SystemThe Focus of My ProjectThe Focus of My Project

Component LimitationsComponent Limitations Measuring Light Throughput EfficiencyMeasuring Light Throughput Efficiency

Results and AnalysisResults and Analysis

The Air Force and Textron The Air Force and Textron

The Air ForceThe Air ForceActive imaging ladar systemsActive imaging ladar systemsMission of tracking and identifying dim space Mission of tracking and identifying dim space

objectsobjects

Textron SystemsTextron SystemsDeveloped technology to support this Developed technology to support this

missionmission

The Maui Space Surveillance The Maui Space Surveillance SiteSite

AEOS3.6m

LaserBeam

LaserReturn

LBD0.6m

The Laser Beam Director (LBD) The Laser Beam Director (LBD) Transmitting TelescopeTransmitting Telescope

LaserLaserLBD telescopeLBD telescopeBeam relay opticsBeam relay optics Laser

LBD Coude Path

Beam Relay Optics

The Beam Relay Optics SystemThe Beam Relay Optics System

• Two JobsTwo Jobs• Direct the laser beamDirect the laser beam• Modify the laser beamModify the laser beam

• IncludesIncludes• MirrorsMirrors• Beam expandersBeam expanders• Cube beam splitterCube beam splitter

The Focus of My ProjectThe Focus of My Project

• Maximize the light throughput of the beam Maximize the light throughput of the beam relay optics systemrelay optics system• To increase the amount of light illuminating To increase the amount of light illuminating

the object of interestthe object of interest

Light Throughput LossLight Throughput Loss

• Light loss occurs whenever light isLight loss occurs whenever light is• AbsorbedAbsorbed• ReflectedReflected• TransmittedTransmitted

• Every component of the system Every component of the system contributes to light throughput losscontributes to light throughput loss

Mirrors

• Use• to change the direction of the laser beam

• Limitations of Real Mirrors• Part is reflected (specular reflection)• Part is absorbed• Part is scattered (diffuse reflection) http://www.play-hookey.com

Beam Expander

• Use• Increase the diameter• Decrease the divergence

• Limitations• Mirrors• Structure

http://www.arachnoid.com

Cube Beam Splitter

• Use• Splits a beam into two beams

• Limitations• Part is transmitted• Part is reflected• Part is absorbed

http://rp-photonics.com

Measuring Light Throughput Efficiency

• Use a power meter• To measure Power In and Power Out

• Light throughput efficiency• (Power out/Power in)*100%

• High efficiency

Cube Beam Splitter

• Problem• Estimated reflecting 30%

• Test Results

Time (s) Power In (mW)

Power Out (mW)

0 127 104

10 128 104

20 128 103

30 128 103

40 128 103

50 128 103

60 128 104

average 128 103

Analysis of the Cube Beam Analysis of the Cube Beam SplitterSplitter

• Light throughput efficiencyLight throughput efficiency• (103mW/128mW)*100% = 80%(103mW/128mW)*100% = 80%

Pellicle Beam SplitterPellicle Beam Splitter

• BenefitsBenefits• Thin membraneThin membrane

• LimitationsLimitations• Thin membraneThin membrane

• Test resultsTest results

http://www.cvilaser.comTime (s) Power In

(mW)Power Out (mW)

0 127 120

10 128 120

20 128 120

30 128 120

40 128 119

50 128 118

60 128 120

average 128 120

Analysis of the Pellicle Beam Analysis of the Pellicle Beam SplitterSplitter

• Light throughput efficiencyLight throughput efficiency• (120mW/128mW)*100% = 94%(120mW/128mW)*100% = 94%

Pellicle vs. CubePellicle vs. Cube

• Improvement of the light throughput Improvement of the light throughput efficiencyefficiency• 94% - 80% = 14%94% - 80% = 14%

Conclusion

• Pellicle

• Optical System Analysis• Beam Expanders

• Mirrors

Acknowledgments•Textron

•Don Ruffatto•Robert Nolan•Robert Lercari•Timothy Georges•Curtis Krupp•Chris Matsuura•Donna Rohrer•Clint Smith•David Schultz•Charles Thurber•Lianne Combo•Caroline Fuji•Arlen Hall•Kelly Kobayashi

•Captain Wright (USAF)•Maui Community College

•Mark Hoffman

•Center for Adaptive Optics & Akamai Workforce Initiative

•Lisa Hunter•Lani Lebron•Nina Arnberg•Mike Nassir

•Short Course Instructors•Dave Harrington•Mike Foley•Mark Pitts

The 2009 Maui Akamai Internship Program is funded by the University of Hawaii, the Department of Business, Economic Development, and Tourism, the National Science Foundation Center for Adaptive Optics (NSF #AST - 9876783)..