SS Chart Template

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LIDAR Technologies Benefiting from SPARCLE
Small Business Innovation Research
Coherent Technologies Inc. Lafayette, Colorado
A key innovation on SPARCLE the Space Readiness
Coherent LIDAR Experiment was the development
of environmentally ruggedized (temperature- and
vibration-insensitive) single-frequency lasers,
as needed for injection-seeding lasers in a
space-borne environment. These lasers were also
frequency-offset locked to each other over a
10GHz range, which is suitable for correcting for
space platform motion in coherent detection
systems.
INNOVATION

• ACCOMPLISHMENTS
• Existing single-frequency laser designs at
  Coherent Technologies were ruggedized for
  operation from a space-based platform to survive
  expected Shuttle launch loads.
• Two such single-frequency lasers were frequency
  offset-locked with a 5 kHz step-size resolution
  over a range of /- 4.5GHz. The short-term
  frequency jitter of the locked laser matched that
  of the reference laser at lt100kHz over a 5
  meter/second (ms) timescale. No additional noise
  was introduced by the locking servo.
• The frequency offset-locked laser was used to
  seed a 125mJ, 6Hz Q-switch pulsed Tm,HoYLF laser
  at 2051nm, generating bandwidth-limited pulses
  over the full /-4.5GHz tuning range of the seed
  laser.
• A detailed design was established for a coherent
  Doppler wind LIDAR transceiver, implementing the
  frequency-agile single-frequency lasers and the
  Q-switch pulsed Tm,HoYLF slave laser. The design
  was in accordance with the requirements set out
  in the Hitchhiker Customer Accommodations and
  Requirements Specifications (CARS) document for
  transporting and operating hardware on the Space
  Shuttle.
• COMMERCIALIZATION
• The ruggedized design of the single-frequency
  lasers developed on SPARCLE has been adopted into
  CTIs standard single-frequency laser METEOR
  product line. While SPARCLE developed only lasers
  at 2051nm (suitable for seeding Tm,HoYLF), the
  METEOR product line has since been expanded
  under CTI and government funding to include a
  variety of materials, including NdYA, YbYAG,
  Yb,Erglass.
• Frequency-agile single-frequency lasers have not
  shown commercial benefit to date but are
  currently being applied to the area of carbon
  dioxide differential absorption LIDAR (DIAL),
  where significant commercial opportunity exists.

Frequency-Agile Single Frequency Lasers.

• GOVERNMENT/SCIENCE APPLICATIONS
• SPARCLE provided the government with a detailed
  design for a coherent Doppler wind LIDAR suitable
  for global wind measurement from the Space
  Shuttle using the Hitchhiker Accommodation
  System.
• The ruggedized and frequency-agile laser
  designs established on SPARCLE are being applied
  to other government contracts/activities by way
  of CTIs METEOR product line, where a
  single-frequency laser is being used as part of a
  larger system. Examples include systems being
  developed at CTI for coherent carbon dioxide DIAL
  measurements for NASA and vibration imaging of
  hard targets for military applications.

Contacts MSFC, Tom Knight 256-544-5353 CTI,
Mark Phillips 303-604-2000, ext. 139 NAS8-40640
(1994 Phase II), NAS8-97320 ( Phase III), and
NAS8-98087 (Phase III)
Marshall Space Flight Center Subtopic 8.03,
LIDAR Remote Sensing Technology August 2002