NASA

1
NASAs Laser Risk Reduction Program- Accomplishm
ents and UpdateUpendra N. Singh
William S. Heaps Chief Technologist, SEC,
NASA LaRC NASA/GSFC 757-864-1570u.n.s
ingh_at_larc.nasa.gov
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Outline

• Background
• LRRP Strategy and Synergies
• Objectives and deliverables
• Recent Accomplishments
• Future Plans
• Conclusions

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Laser Risk Reduction Program Origins

• Earth Science Independent Laser Review Board
  empanelled in 2000 in response to multiple laser
  instrument mission issues
• Panel reviewed past and present NASA ESE laser
  remote sensing missions
• CALIPSO, ICESat, LITE, SPARCLE (NMP/EO-2), VCL
• Panel report included 11 recommendations, the
  most key being
• NASA should identify and intensively develop
  critical fundamental technologies applicable to
  multiple missions and investigate formation of
  interagency coalition to assure supply of diode
  pumped lasers
• NASA should create a Laser Research Super
  Center managed by NASA HQ and drawing from laser
  research teams at the field centers
• An interagency technology alliance should be
  formed for the development of space-based active
  optical sensors and associated critical enabling
  technologies (especially transmitter-class
  lasers)
• NASA Administrator mandated formulation of an
  Agency-level lidar technology development plan
• Laser Risk Reduction Program (LRRP) was
  established, based on recommendations from joint
  LaRC/GSFC strategy team
• Program initiated in FY02
• Co-funded by ESTO and Code R Enabling Concepts
  and Technologies (ECT) program

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INLSST Charter

• Develop lidar technology for NASAs future
  measurements
• Assemble in-house NASA team with end-to-end lidar
  capability (theory to hardware to validation)
• Collaborate with industry, academia, and
  government
• Validate technology to reduce risk of space-based
  lidar missions before the proposal process
• Transfer technology to industry

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Overview
Laser based instruments are applicable to a wide
range of Earth Science, Aerospace Technology,
Space Science, and Space Flight Enterprise
needs Risk in lidar missions can be significantly
reduced by progress in a few key
technologies Modest NASA investment towards
proposed strategy will have significant impact on
future space-based active remote sensing
missions Strategic alliance with other government
organizations, industry, and academia for
leveraging and accelerating advancement of key
technologies
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Integrated NASA Lidar Systems Strategy Team Report

• Presentation to
• Daniel S. Goldin, NASA Administrator
• By
• Ghassem R. Asrar Samuel L. Venneri
• Associate Administrator Associate
  Administrator
• Earth Science Enterprise Aerospace Technology
  Enterprise
• Jeremiah F. Creedon Alphonso V. Diaz
• Director, NASA LaRC Director, NASA GSFC
• Upendra N. Singh and William S. Heaps
• Co-Leaders
• Integrated NASA Lidar Systems Strategy Team
  (INLSST)
• June 18, 2001

Draft Copy
Preliminary Draft For Agency Use Only
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Lidar is a Multi-Enterprise Need
Clouds/Aerosols Tropospheric Winds Ozone Carbon
Dioxide Biomass Burning Water Vapor Surface
Mapping Laser Altimetry Oceanography
NASA Enterprises Needs
Earth Science
Aerospace Technology
Laser Technology
Space Science
Space Flight
Mars Lander Guidance/Control
Mars Atmospheric Sensing
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Earth Sciences Application Foci

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

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Lidar Techniques and Measurements

• Differential Absorption Lidar (DIAL)
• Ozone
• Carbon Dioxide

• Doppler Lidar
• Wind Fields
• River Flow

• Backscatter Lidar
• Cloud
• Aerosol

• Altimetry Lidar
• Ice Sheet Mass Balance
• Vegetation Canopy
• Land Topography

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Earth Sciences Application Foci
2 Lasers, 4 Techniques, 6 Priority Measurements
Pulsed Laser Development
2.05 micron
DIAL CO2
Backscatter Lidar Aerosols/Clouds
Coherent Ocean/River Surface Currents
2 MICRON
2.05 micron
Atmosphere Lower Upper

Doppler Lidar Wind
Key Technologies in Common Laser Diodes Laser
Induced Damage Frequency Control Electrical
Efficiency Heat Removal Ruggedness
Lifetime Contamination Tolerance
Coherent Winds
Coherent
Direct
Noncoherent Winds
0.355 micron
X3
1 MICRON
X2
Altimetry
Surface Mapping, Oceanography
1.06 micron
DIAL Ozone
X2
0.30-0.32 micron
Backscatter Lidar Aerosols/Clouds
0.532 micron
OPO
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Laser Transmitter Testbeds
Laser Induced Damage Now 15 J/cm2 for 5
nsec Goal 60 J/cm2 for 5 nsec
Contamination Tolerance Now 50, A/10 Goal
Better Tolerance
Ruggedness Now 1 min _at_ 10G Goal 1 min _at_ 15 G
Lifetime Now 850? M shots Goal 2 G shots
2 µ Test Bed
Knowledge
1 µ Test Bed
Heat Removal Now 110 Watts Goal 300 Watts
Frequency Control Now lt .25 pm Goal lt .005 pm
Electrical Efficiency Now 3-4 Goal 6
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Recommendations

• Establishing Space-hardened Laser Transmitter
  Test Beds (1µm laser at GSFC 2µm at LaRC)
• Development and Qualifications of Space-based
  Laser Diode Arrays ( 808nm diodes at GSFC
  792nm at LaRC)
• Advancing Wavelength Conversion Technology
  for Space-based Lidars ( Low Energy/HRT at
  GSFC High Energy/LRT at LaRC)

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NASA Laser Risk Reduction Program

• Deliverables
• Space-hardened 1- and 2-micron Laser Transmitters
  (Efficient, Conductively-cooled)
• Space-hardened Conductively Cooled Laser Diode
  Arrays
• Non-linear Optical Parametric and Harmonic
  Generation for Ozone, Chemical and Biological
  Species, and Water Vapor Detection

Funding (M) FY 03 FY 04 FY 05 FY 06 FY 07 FY 08
OAT 5 5 5 5 5 5
OES 4 4 4 4 4 4
Total 9 9 9 9 9 9
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Laser Risk Reduction Management Model
NASA HQ
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LRRP Description

• Pro-actively targets deficiencies in laser
  technology for focused development and risk
  mitigation
• Technology readiness overestimated in past due to
  extrapolation from prior heritage
• Flight lasers are still at the build-to-order
  RD stage
• Primary focus is on high-power (i.e.,
  transmitter-class) lasers for space-based remote
  sensing applications
• High-performance NdYAG systems (1 µm)
• Emerging holmium- and thulium-doped lasant
  materials (2 µm)
• Nonlinear generation schemes based on 1- and 2- µ
  m pump sources
• Harmonic generation
• Optical parametric amplification/oscillation
  (OPA/OPO)
• Small investments in ancillary enhancing and
  enabling technologies which offer potential to
  reduce demand for laser power (detectors,
  innovative receiver approaches)

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LRRP Application Driven Elements

• 2-micron laser transmitter
• Demonstrate technologies leading to a
  conductively cooled, diode-pumped 2-micron laser
  suitable for space-based lidar application
• Address major laser development issues High
  energy, high efficiency, laser-induced optical
  and thermal damage, system thermal management
• High-power diode laser pump arrays
• Develop, scale, and qualify long-lived,
  space-compatible laser diode arrays with current
  vendors
• Evaluate currently available laser diode arrays
  for performance, life and configuration required
  for future space-based laser missions
• Establish Characterization and Lifetime Test
  Facility to address laser diode issues
• Limited reliability and lifetime
• Lack of statistical and analytical bases for
  performance and lifetime prediction
• Conceive advanced laser diode array architectures
  with improved efficiency and thermal
  characteristics
• Nonlinear optics research for space-based ozone
  DIAL
• Spectrally narrow, tunable, robust UV laser
  architectures
• Develop long-lived, efficient, space-compatible,
  nonlinear optical materials/techniques
• Receiver technologies
• Develop integrated heterodyne receiver to
  demonstrate 3-dB improvement of coherent lidar
  system efficiency with 80 reduction of required
  local oscillator power
• Develop improved quantum efficiency
  photon-counting detectors at 2 micron
• Laser physics and advanced materials research
• Develop line tunable diode-pumped Nd laser system
  for pumping nonlinear UV generation schemes
• Develop narrowband, long pulse, low average power
  pump laser for wavelength control of lidar systems

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NASA Laser Risk Reduction Program

• Differential Absorption Lidar (DIAL)
• Carbon Dioxide
• Ozone

Wavelength Conversion
Space Qualification
Pump Diodes
Laser Design

• Doppler Lidar
• Wind Fields
• River Flow

Heat Removal (All Conductive)
Laser Physics
OPO/OPA
Performance
Contamination
Materials
SHG/THG
Compact
Packaging
Heritage derived from both Earth and Solar System
apps.
Modeling

• Backscatter Lidar
• Cloud
• Aerosol

Optics Damage (2G/3 yr)
Efficiency (Green30 UV20)
Coupling
Energy (1 J)/ Power (10-100W)
Lifetime (2G Shots)
Failure Mechanisms
Beam Quality
Efficiency (4 WPE)
Lifetime Effects
Beam Quality/ Spectrum
Availability (COTS)

• Laser Altimeter
• Ice Sheet Mass and Topography
• Vegetation Canopy
• Land Topography
• Ocean Mixed Layer Depth
• S/C-S/C Ranging

Flight Demonstrations
2-Micron Laser
1-Micron Laser
2003
2007 Missions
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Enabling Technology Elements
Customers
Laser Transmitter Technologies
Lidar Technologies
Measurements
Y S
UV Wavelength Converter
1-Micron Lidar Transmitter
Clouds/Aerosols
X
X
IR Wavelength Converter
X
Global Winds
X
X
Amplifier
X
X
Chem/Bio Sensing
Frequency Controller
CO2 Profiling
X
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Laser Risk Reduction Program

• Pump Laser Diodes Risk Reduction
• LaRC to advance diodes in 790 nm wavelength
  region
• Lifetime and characterization testing
• Radiation testing performed at GSFC
• Conductively cooled laser
• 2-micron partially conductively-cooled laser is
  precursor to fully conductively-cooled
  space-capable design
• Contamination
• GSFC Contamination protocols will be made
  available to support the contamination lifetime
  study and tests at LaRC
• Non-Linear Material OPO Modeling
• LaRC to develop high peak power OPOs
• Non-linear materials to be included in diode
  radiation test
• Design and Packaging
• Packaging methodology for space flight-capable
  laser

A
B
C
D
E
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Laser Risk Reduction ProgramLaRC Component
C Contamination Lifetime Study and Tests
Material Res Quantum Mech. Modeling
Rad Damage Tests
Laser Resonator Power Efficiency
Multi-Joule 12Hz 2-micron Transmitter Laser
Global Winds CO2
E Packaging (Flight-Hardened System)
B Conductively-Cooled Laser Head
Laser Amplifier
Laser Oscillator
A Rad Th/Vac Tests
Test/Charact. Facility
Life Test Quality
Test Perf./Reliability
Laser Diodes Availability Life/Quality
A Advance Laser Diode Technologies
A Contamination Handling Protocols
Define Reqmts Innovations
Qualification Procedures
Low-Noise Detector for CO2 Meas.
Characterization Facilities
Receiver Subsystem Efficiency Size/Mass
Lightweight Scanning Telescope
Global Ozone
Highly-Efficient Heterodyne Receiver
Define Reqmts Innovations
Dual Pump Parametric Oscillator
D Non-linear material OPO modeling
Wavelength Conversion Power Efficiency
100mJ _at_ 100Hz 308nm 320nm 2 efficiency
Efficient conversion to UV
Damage/Rad/ Life Tests
Packaging
Lab Demo High Power Conversion to UV
Normal Mode Intra-cavity SHG Pump Laser
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Laser Risk Reduction Program2-micron technology
roadmap
Partially conductively-cooled osc
1.5J, 2Hz Partially conductively-cooled 2-micron
laser
Laser Resonator Design
Partially conductively-cooled laser head
Validation tool
Partially conductively-cooled amp
Design Lessons
Design Lessons
Design Lessons
Fully conductively-cooled osc
1.5J, 10Hz Fully conductively-cooled 2-micron
laser
Space-capable design
Fully conductively-cooled laser head
Fully conductively-cooled amp
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2-Micron Pulsed Transmitter Laser
Objective Develop a high energy, high
efficiency, conductively-cooled solid-state
2-micron laser for space lidar applications. Appli
cation Measurement of global CO2 and winds from
LEO.
1 J

• Accomplishments
• Successful demonstration of Ho,TmLuLF laser
  system with 1050 mJ Q-switched output energy.
  This was accomplished by one power oscillator and
  two amplifiers operating in double pulse mode.
  Single-pulse output is 0.6 J.
• Notional space-based wind profiling missions
  require pulse energies from 1 to 5 J, depending
  on the scenario
• Milestone achieved with 2-Hz PRF gt12 Hz desired
  for LEO

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Pump Laser Diode Advancement and Validation
Objective

• Develop state-of-the-art characterization and
  life-time test facility and address 792-nm laser
  diode issues
• Limited reliability and lifetime
• Lack of statistical and analytical bases for
  performance and lifetime prediction
• Limited commercial availability
• Develop advanced laser diode array (LDA)
  architectures with improved efficiency and
  thermal characteristics

Thermal Image of Diamond LDA
Accomplishments Fabricated and tested an
advanced LDA package utilizing diamond substrate
and heatsink. Demonstrated 17 reduction in
thermal resistance relative to the
standard BeO/Cu package that can translate to
increased lifetime and reliability.
Diamond Package cools 36 faster
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LRRP Recent Accomplishments

• Reached 150 mJ (record) of UV at 320 nm with 10
  (record) 1µm-UV efficiency reached 115 mJ at 308
  nm
• Developed innovative UV generation architectures
• Critical to trop ozone profile measurement from
  space

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Laser Risk Reduction Program- Collaborations

• Current partnerships and collaborations

• JPL
• Tunable LO Laser
• Integrated Receiver

• VLOC, CVI
• Optics
• Coatings

• Coherent, CEO,
• Laser Diodes

• Northrop Gruman
• Solid State Lasers

LaRC GSFC
NASA Laser/Lidar Risk Reduction Program

• Swales, UMD
• Cond. Cool. Pkg.

• DOE
• UV Laser

• ITT
• UV Laser

• JHU, APL
• Non Linear Op

• Schafer,
• Plasma Processes
• Lightweight Telescopes

• Sci. Material
• Laser Crystals

• Boston College
• Quan. Mech. Model.

• DOD
• Laser Diodes,
• EO Scanner

• Industry
• University
• Government

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Proposal for a Multi-Agency AORS Consortium

• National Consortium for Excellence in Active
  Optical Remote Sensing (AORS)
• Purpose To establish and maintain critical
  national expertise needed to ensure long term
  progress in AORS mount compelling case for new
  USG initiative in FY05-06 timeframe
• Participants
• A multi-agency entity (e.g., NASA, NOAA, IPO,
  DoD, DoE, FAA, Homeland)
• Engages members of academia and industry
• Approach
• Leverages complementary activities ongoing in
  each of those organizations
• Primary interchange through open discussions

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Proposed Consortium Partners and
Measurement Needs
Clouds/Aerosols Wind Trop. Chemistry Carbon
dioxide Biomass Water Vapor Land/Ice
Topography Wake Vortices Ocean Mixed Layer Solar
System Science
NSF
Chem-Bio Detection Aviation Safety Wake
Vortices Turbulence Wind Shear
Academia
Industry
NASA
FAA
Chem-Bio Det Aerosols Wind Aviation Safety
Multi-Agency Active Optical Remote Sensing
Consortium
Wind Water Vapor CO2 Aerosols
Home- land
NOAA
Wind Humidity Aerosols
Wind Aerosols Chem-Bio Detection Target
Recognition Tactical Imaging
IPO
DoD
DoE
Water Vapor Chem- Bio Detection Clouds and
Aerosols
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Consortium Structure
Executive Council
Steering Committee
Working Groups
Clouds/ Aerosols
Ranging
Aviation Safety

• NASA
• USGS
• DOD
• Homeland

• NOAA
• NASA
• IPO
• DOD
• Homeland

• NASA
• FAA
• DOD
• Homeland

Water Vapor
Wake Vortices

• NOAA
• NASA
• IPO
• DOE
• EPA

• FAA
• NASA
• DOD

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Advanced AORS Technology Elements
AORS System Demonstration Packaging
Hardening Flight Validation
DETECTOR
TELESCOPE
SCANNER
RECEIVER
LASER LASER
1 micron Laser Testbed 2 micron Laser Testbed
Wavelength Conversion Laser Diode Pump Space Hardening Packaging Wavelength Conversion Laser Diode Pump Space Hardening Packaging
Auto-Alignment
POINTING
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Summary

• Developing AORS technology supports NASAs Vision
  and Mission and enables a key building block
• A focused technology effort will enable the
  promise of AORS by closing critical remaining
  gaps in capability
• AORS will address key high resolution measurement
  needs within Codes Y and S and support other
  national needs

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Backup Charts
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Technology Roadmap 2-micron UV Sources
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LRRP Recent Accomplishments

• Developed diode laser characterization facility
• Diagnostics to understand failure modes of solid
  state lasers
• Enables active wind CO2 measurement from space

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LRRP Recent Accomplishments
792 nm Diamond Package LDA
Diamond Package dissipates excess heat more
efficiently than standard BeO/Cu package
resulting in increased lifetime.
Thermal resistance of diamond package is 17
lower than BeO/Cu package
Pulsewidth 0.1 1.0 msec Current 80 A Rep
Rate 10 Hz Op Temp 15oC
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Thermal Characteristics of Diamond LDA

• Enables all lidar measurements

Diamond Package cools 36 faster