Update On The NASA Laser Risk Reduction Program (LRRP) Michael J. Kavaya, Upendra N. Singh NASA/LaRC Working Group on Space-Based Lidar Winds Oxnard, CA Feb. 17, 2003

History Of New LRRP Initiative Code Y Space Lidar Mission Risks External Review & Recommendations (11/00, Alejandro et al) New Code R ’02 Initiative Integrated NASA Lidar Systems Strategy Team (INLSST) Studies & Recommendations New Code Y ’02 Initiative (6/01, Singh, Heaps, et al)

Independent Laser Review Panel Alejandro, Hardesty, Hicks, Killinger, Lapp: NASA should: Develop critical technology elements before a science mission Insist on advanced TRL before science mission approval Insist on science-technology tradeoff Maintain internal laser expertise etc.

Key Priority Measurements for Earth Science Enterprise Cloud/Aerosols and Radiative Forcing Tropospheric Winds Tropospheric Ozone Carbon Cycle (CO2, Biomass) Surface Mapping Oceanography

NASA Laser Risk Reduction Program 2 Lasers, 4 Techniques, 6 Priority Measurements Pulsed Laser Development 2.05 micron DIAL: CO2 Backscatter Lidar: Aerosols/Clouds 2 MICRON 2.05 micron Atmosphere: Lower Upper Doppler Lidar Coherent Winds Key Technologies in Common Laser Diodes Laser Induced Damage Frequency Control Electrical Efficiency Heat Removal Ruggedness Lifetime Contamination Tolerance High Accuracy High Resolution Lower Trop. & Clouds Coherent Hybrid Lidar Winds Noncoherent Winds Direct Global Coverage Medium Resolution Medium Accuracy Mid/Upper Atmosphere 0.355 micron X3 1 MICRON X2 Altimetry: DIAL: Ozone 1.06 micron Surface Mapping, Oceanography Backscatter Lidar: Aerosols/Clouds X2 0.532 micron 0.30-0.32 micron OPO

Components Of LRRP GSFC Areas of Concentration: 1-Micron Laser Development Pump Diode Characterization (808 nm) Wavelength Conversion From 1-Micron to UV, High P LaRC Areas of Concentration: 2-Micron Pulsed Transmitter Laser Development Pump Laser Diode Arrays Development, Characterization, & Qualification (792 nm) Wavelength Conversion From 1-Micron to UV, High E Detector/Receiver Advancement For Coherent and Direct Detection at 2-Microns

LRRP Roadmap - LaRC C E B A D AAdvance AContamination Multi-Joule & Lifetime Study and Tests Material Res & Quantum Mech. Modeling Rad & Damage Tests Laser Resonator Power Efficiency Multi-Joule 12 Hz 2-Micron Transmitter Laser E Packaging (Flight-Hardened System) Global Winds & CO2 B Conductively-Cooled Laser Head Laser Oscillator Laser Amplifier Test/Charact. Facility A Rad Th/Vac Tests Test Perf./Reliability Life Test Quality Laser Diodes Availability Life/Quality AAdvance Laser Diode Technologies Define Reqmts & Innovations AContamination & Handling Protocols Qualification Procedures Characterization Facilities Low-Noise Detector for CO2 Meas. Receiver Subsystem Efficiency Size/Mass Lightweight Scanning Telescope Global Ozone Meas. Define Reqmts & Innovations Highly-Efficient Heterodyne Receiver D Non-linear Material Res. & OPO Modeling Dual Pump Parametric Oscillator Wavelength Conversion Power Efficiency 500 mJ X 10 Hz 308nm &320 nm 2% Efficiency Efficient, High E Conver to UV Damage/Rad/ Life Tests Packaging Lab Demo High Power Conversion to UV Normal Mode Intra-cavity SHG Pump Laser FY 02 FY 03 FY 04 FY 05 FY 06 FY 07 FY scale not exact

LRRP Roadmap - GSFC E D ATest Set A C C B 1 µm Laser What? How? Define Reqmnts Define Architecture/ Prel. Design E Design/Pack aging Stage I Fabrication/ Integration Stage II Fabrication/ Integration Compo- nent Dev. D Test Set Life Damage Rad Test Freq. Control/ Con- version What? How? ID Candidate Materials Packaging Scaling Seeder Develop- ment 1J 100W TBD micron TBD mJ 50 Hz TBD W 1 micron ATest Set Procure LDA’s Scaleup Scaleup Laser Diodes Supply? Life/Qual? Life Test/Qual A Radiation Test C Clean/ Cont Protocols/ Flows Conta- mination/ materials What? How much? Control? Innovative Technique Develop Processes Current Practice Survey C Establish How much/ what vs damage Thermal Control What? How? Stage I Dev Stage II Dev B Scaling/ Innovative Techniques FY02 FY03 FY04 FY05 FY06

NASA Laser Risk Reduction Program Differential Absorption Lidar (DIAL) Carbon Dioxide Ozone Laser Design Pump Diodes Wavelength Conversion Space Qualification Doppler Lidar Wind Fields River Flow Heat Removal (All Conductive) Laser Physics OPO/OPA Performance Contamination Materials SHG/THG Compact Packaging Modeling Optics Damage (2G/3 yr) Backscatter Lidar Cloud Aerosol Efficiency (Green=30% UV=20%) Coupling Energy (1 J)/ Power (10-100W) Lifetime (2G Shots) Failure Mechanisms Efficiency (4% WPE) Beam Quality Beam Quality/ Spectrum Lifetime Effects Availability (COTS) Altimeter Lidar Ice Sheet Mass and Topography Vegetation Canopy Land Topography Oceanography S/C-S/C Ranging 2-Micron Laser NMP 1-Micron Laser 2003 2007 Missions

LRRP Funding Gross Funding ($M): FY02 FY 03 FY 04 FY 05 FY 06 FY 07 Total LaRC OAT (R) 1.8 2.5 14.3 OES (Y) 2 12 GSFC 1 13.5 6.8 9 51.8

2-Micron Pulsed Transmitter Laser Products Personnel Dr. Jirong Yu Dr. Yingxin Bai Dr. Songsheng Chen Dr. Hyung Lee George Lockard Ed Modlin Keith Murray Mulugeta Petros Bo Trieu SWALES FY02 Accomplishments FY03 Milestones Evaluated techniques to couple laser diode pump light into 2-micron solid state laser crystal Completed versatile modular fully conductively cooled 2-micron solid state laser head design Completed partially conductive cooled laser head design and manufacture; began testing 95 mJ, 10 Hz PCC LuLF demonstrated Demo 3-9 micron ZnGeP2 OPO 6/03 - Complete fabrication of fully conductive cooled laser head 9/03 - Evaluate head assembly and thermal management performance 9/03 - Complete engineering hardened partially conductive cooled laser head design

Pump Laser Diode Advancement and Validation Products Personnel Efficient, Reliable, High Power, Conductively-Cooled Laser Diode Arrays suitable for long lifetime space missions. Dr. Farzin Amzajerdian Ned Baker Thomas Gabany Dr. Carl Magee Byron Meadows Dr. Vikas Sudesh Industrial Partners Laser Diode Array FY02 Accomplishments FY03 Milestones 3/03 - Complete assembly of laser diode characterization facility 4/03 - Fabricate an advanced laser diode array package 5/03 - Develop thermal map/heat dissipation test setup 9/03 - Complete lifetime test automation 9/03 - Characterize 792 nm laser diode arrays in standard A and G packages Initiated construction of laser diode characterization facility (LDCF) Initiated collaboration with GSFC and industry Completed LDCF Characterized 25 LDAs Fabricated 7 advanced LDAs

UV Wavelength Conversion Technologies from 1 Micron Products Personnel Dr. Larry Petway Chris Edwards Matthew Turner Julie Williams-Byrd DOE Sandia National Laboratory FY03 Milestones 2/03 - Optimize performance of modified commercial Nd:YAG pump laser 3/03 - Demonstrate highest possible depletion of pump beam energy in RISTRA OPO 9/03 - Obtain maximum UV output at 320 nm using sum frequency mixing of OP output and Nd:YAG laser 2nd harmonic. With a goal to demonstrate 200 mJ at 320 nm with 1 micron to UV efficiency of 15 to 20% at LaRC 9/03 - Obtain maximum UV output at 320 nm using sum frequency mixing of OP output and Nd:YAG laser 2nd harmonic. With a goal to demonstrate 200 mJ at 320 nm with 1 micron to UV efficiency of 15 to 20% at Sandia FY02 Accomplishments Reached 150 mJ of UV at 320 nm with 10% 1 micron to UV efficiency; reached 115 mJ at 308 nm (world records) Established UV collaboration with Sandia National Laboratory (DOE); trying for 200 mJ & 20% 1-UV efficiency at 320 nm Developed plan to merge 2 novel technologies

2-Micron Detector Development - Direct Products Personnel Dr. Nurul Abedin Dr. Tamer Refaat FY03 Milestones 4/03 - Materials growth and substrate preparation 7/03 - LPE epitaxial growth and optimization 9/03 - Device design and fabrication 9/03 - Carrier transport model for the homojunction InGaSb-based avalanche devices 12/03 - Analysis of the dark currents and their dependence on temperature, electric field and trap/defect density for the homojunction InGaSb APD device Conceptual Design of 2-Micron APD FY02 Accomplishments Developed numerical model and verified with InGaAsSb photodetector experimental data Completed characterization of several IR detectors

2-Micron Receiver Subsystem - Coherent Products Lightweight Scanning Lidar Telescope Personnel Integrated Heterodyne Photoreceiver Dr. Farzin Amzajerdian Jonathan Branson JPL MSFC Industrial Partners Detectors, processing electronic, and Semiconductor Local Oscillator Laser Integrated on a Single Chip Thermally-stable Telescope Using Metal Alloy Shell Optics and Structure FY02 Accomplishments FY03 Milestones 3/03 - Complete design of an optimized heterodyne photoreceiver based on measured detector parameters 3/03 - Fabricate nickel shell pathfinder flat mirrors 9/03 - Fabricate a 15-cm demonstrator mirror 9/03 - Fabricate integrated fiber-coupled detector/amplifier based on dual balanced detectors Completed fabrication of integrated detector/preamplifier Established in-house team for design, integration, and test Developed collaboration plan with JPL Produced first plasma sprayed nickel shell mirror test pieces

Laser Physics, Quantum Mechanical Models, and Advanced Materials Research Products Personnel Develop a simple, line tunable laser system based on diode pumped Nd laser technology for lidar applications in the ultraviolet such as ozone and sulphur dioxide. Develop a narrow spectral bandwidth, long pulse length, low average power pump laser for wavelength control of lidar systems. Continuous laser systems require too much power and short pulse laser systems have timing issues. Dr. Norman Barnes Dr. Theresa Axenson Don Reichle Dr. Brian Walsh Boston College Industrial Partners FY02 Accomplishments FY03 Milestones 1/03 - Diode-pumped Nd:YAG ring oscillator 6/03 - Relaxation oscillation suppressed oscillator 9/03 - Optimize second harmonic generation 3/03 - Measure Nd:YAG efficiency on feasible laser transitions 12/03 - Demonstrate 2-wavelength oscillation Quantum mechanical model improved and results presented at conference; measured material spectra Demonstated tuning of pulsed Nd:YAG Designed, assembled, demonstrated dual wavelength laser Demonstrated laser wavelength mixing for ozone application

Mobile Lidar Technologies Test Bed Products Personnel Dr. Grady Koch Bruce Barnes Dr. Jeffrey Beyon Joseph Goad, Jr. California State University University of Colorado FY02 Accomplishments FY03 Milestones 1/03 - Install refurbished 2-micron pulsed laser 2/03 - Test SPARCLE telescope 4/03 - First intercomparison 5/03 - Install and test data acquisition system 9/03 - Field testing Vector wind profiles measured with mobile trailer lidar Best ever precision (5%) of coherent DIAL CO2 demonstrated

Back Up Slides

NASA Enterprises Needs NASA Laser Risk Reduction Program Clouds/Aerosols Tropospheric Winds Ozone Carbon Dioxide Biomass Burning Water Vapor Surface Mapping Laser Altimetry Oceanography Turbulence detection Wind shear detection Wake vortices NASA Enterprises Needs Earth Science Aerospace Technology Laser Technology Space Science HEDS Mars Lander Guidance/Control Atmospheric Sensing Automatic Rendezvous and Docking for ISS Wind profiling for shuttle launch and landing

NASA Laser Risk Reduction Program E-O Scanner Integrated Photo- Receiver Lightweight Telescope Automatic Alignment Low-Noise Detector Lidar Technologies Frequency Controller Space CO2 Lidar 2- micron Lidar Transmitter Amplifier Space Wind Lidar Aeronautic Lidar IR Wavelength Converter Chem/Bio Lidar 1- micron Lidar Transmitter UV Wavelength Converter Space Ozone Lidar

NASA Laser Risk Reduction Program Lidar Techniques Differential Absorption Lidar (DIAL) Carbon Dioxide Ozone Doppler Lidar Wind Fields River Flow loff lon Transmit Pulses Returns Concentration = log[ I(lon)/ I(loff)] Wavelength fDoppler Frequecy Transmit Pulse Return Velocity = (l/2) fDoppler Backscatter Lidar Cloud Aerosol TArrival Time Transmit Pulse Return Density = IS/IT Range = (c/2)Tarrival IT IS TArrival Time Transmit Pulse Return Range = (c/2)TArrival Altimeter Lidar Ice Sheet Mass and Topography Vegetation Canopy Land Topography Oceanography